THE KENYA POWER AND LIGHTING COMPANY LIMITED

KENYA ENERGY SECTOR RECOVERY PROJECT DISTRIBUTION REINFORCEMENT AND UPGRADE

BIDDING DOCUMENTS FOR

Contract: IX

Design, Supply and Installation of Substations & Lines

GROUP SCHEMES

(Additional Credit)

VOLUME II

August 2010

Part 1 Bidding Procedures

Part 3 Conditions of Contract and Contract Forms

Part 2 Employer’s Requirements

These Bidding Documents have been prepared following the guidelines of the World Bank Standard Bidding Document for Procurement of Plant Design, Supply, and Installation of August 2010

Table of Contents

VOLUME I

PART 1 – BIDDING PROCEDURES

Section I: Instructions to Bidders (ITB)

Section II. Bid Data Sheet (BDS)

Section III. Evaluation and Qualification Criteria

Section IV Bidding Forms

Section V. Eligible Countries

PART 3 CONDITIONS OF CONTRACT AND SAMPLE FORMS

Section VII. General Conditions (GC)

Section VIII. Particular Conditions (PC)

Section IX: Contract Forms

VOLUME II

PART 2 SECTION VI EMPLOYERS REQUIREMENTS

1.0 Specifications

1 – 1 Technical Specifications

1 – 4 Technical Schedules

2.0 Scope of Supply

2 – 5 Scope of works Lines

2 – 6 Scope of work distribution substations

3.0 Drawings

4.0 Forms of Contract and procedures

Acronyms

AFD Groupe Agence Francais de Devloppement

BDS Bid Data Sheet

CIF Cost, Insurance and Freight

CIP Carriage and Insurance Paid to (place)

CPM Critical Path Method

EDI Electronic Data Interchange

EIB European Investment Bank

ENAA Engineering Advancement Association of Japan

EXW Ex factory, ex works or ex warehouse

FCA Free Carrier

FIDIC Fédération Internationale des Ingénieurs Conseils (International Federation of Consult-ing Engineers)

FOB Free on Board

GCC General Conditions of Contract

IBRD International Bank for Reconstruction and Development

ICC International Chamber of Commerce

IDA International Development Association

IFB Invitation for Bids

ITB Instructions to Bidders

NDF Nordic Development Fund

SBD Standard Bidding Document

SCC Special Conditions of Contract

TS Technical Specifications and Drawings

UNCITRAL United Nations Commission on International Trade Law

REPUBLIC OF KENYA

THE KENYA POWER & LIGHTING COMPANY LIMITED

Technical Specifications

33KV,11KV AND 0.433KV Lines And Pole Mounted substations

The Kenya Power & Lighting

Co. Ltd.

Table of Contents 1.0 General Specifications ………………………………………………………….. 3 1.1 Scope………………………………………………………………………...3

1.2 Description of the Project ………………………………………………. 4 1.3 Standards…………………………………………… ……………...…… 4 1.4 Unit of measurement ……………………………………………………. 4 1.5 Service Conditions …………………………...……………………….... 4 1.6 Working stress and design…………………………………………….. 6 1.7 Basic Requirements for Electrical Equipment ……………………......... 10 1.8 Earthing systems, Electrodes and connections……………………………. 14 1.9 Materials and Workmanship ……………………………………………….17 1.10 Safety Precautions …………………………………………………… 20 1.11 Protection, Clearing and Painting ……………………………………… 21 1.12 Embedded Metal Work, Opening, etc. ………………………………… 22 1.13 Spare Parts …………………………………………………………….. 22 1.14 Packing ………………………………………………………………… 23 1.15 Delivery ………………………………………………………………... 24 1.16 Cleaning and Material Disposal ……………………………………….. 24 1.17 Programme and Progress ……………………………………………… 25 1.18 Drawings and Data to be Supplied by the Contractor …………………. 25 1.19 Operating and Maintenance Instructions ………………………………. 27 1.20 Test Procedure Instructions ……………………………………………. 28 1.21 Equipment testing at place of manufacture……………………. …… 28 1.22 Photographs ……………………………………………………………. 29

2.0 Technical Specifications for Substations ……………………………………..... 29

2.0 Distribution Transformers……………………………………………….... 29 2.01 Single phase distribution transformers ........................................................ 29 2.1 Specification for three phase distribution transformer..................................35 2.2 Local Station Service Transformer ……………………………………. 41 2.3 33kv Circuit breaker ………… ……………………………………. 41 2.4 33KV Three Phase Isolators…………………………………………….. 41 2.5 33KV Voltage Transformers……………………………………………… 44 2.6 33kv Current Transformers…………………………………………..……...44 2.7 33kv Surge Arresters……………………………………………………... ...44 2.8 11kv Autoreclosers…………………………………………………………..46 2.9 11kv metal clad indoor switchgear………………………………………......51 2.10 Protection relays, controls and measuring devices panels…………….……. 51 2.11 Electrical protection relays………………………………………….…….....52 2.12 Energy meters……………………………………………………….……….52 2.13 Battery and charger……………………………………………….………….52 2.14 Substation low voltage panels………………………………………………..51 2.15 11kv isolators………………………………………………………………...52 2.16 11kv surge diverter…………………………………………………………..54 2.17 Low Voltage cables………………………………………………………… 55 2.18 Insulators, fittings and substation structures………………………..………..57 2.19 Electrical cables and fittings…………………………………………………59 2.20 Civil Engineering and Building works………………………………………59 2.21 Test at site …………………………………………………………………...68

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3.1 General Requirements………………………………………………………60 3.2 Overhead construction materials.…………………………………… 62 3.3 Overhead Aluminuim Conductors Steel reinforced…………………………63 3.4 All Alumium conductor soft drawn…………………………………………67 3.5 PVC covered copper conductors…………………………………………….69 3.6 Bare copper conductors……………………………………………………..71 3.7 33 and 11kv Composite insulators…………………………………………..73 3.8 33 and 11kv porcelain insulators…………………………………………….74 3.9 Low voltage insulators………………………………………………………76 3.10 Line supports and foundations………………………………………………77 3.11 Stay, Stay Insulators and Stay Blocks ………………………….................. .81 3.12 Fasterners and washers for overhead lines…………………………………..87 3.13 Overhead lines fittings……………………………………………………….92 3.14 Binding wires and stirrups…………………………………………………...96 3.15 Pole signs and accessories…………………………………………………....98 3.16 Conductor sleeve joint………………………………………………………..99 3.17 Steel works for Ovehead lines………………………………………………..105 3.18 Earthing………………………………………………………………………123 3.19 11kv Expulsion fuse links……………………………………………………126 3.20 11kv expulsion fuse cutout…………………………………………………..127 3.21 33kv expulsion fuse cutout…………………………………………………..129 3.22 33kv expulsion Fuse holder………………………………………………….131 3.23 low voltage cartridge fuses………………………………………………….. 133 3.24 Low voltage fuse cut-out…………………………………………………… 136 3.25 Low voltage Air Bundled Cables…………………………………………… 138 3.26 Single core LV Aluminium cable 300 & 630mm sq…..…………………… 142 3.27 Single core LV Copper cable ……………………..………………..…… 144 3.28 Four core LV aluminium cable………………………………………………146 3.29 Terminal lugs…………………………………………………………………146 3.30 Cable glands………………………………………………………………….148 3.31 Concrete cable covers………………………………………………………...154 3.32 Pole mounted low voltage circuit breakers..................................................... 162 3.33 EP Voltage regulating transformers................................................................. 165 3.34 Insulating Tapes……………………………………………………………... 166 3.35 Operation Devices and Protection systems………………………………….. 166 3.36 Protection against Overvoltages…………………………………………….. 166 3.37 Environmental Requirements ………………………………………………. 166 3.38 Wayleaves ………………………………………………………………….. 166

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TECHNICAL SPECIFICATIONS & DRAWINGS

1. GENERAL SPECIFICATIONS 1.1 SCOPE OF WORKS:

The contract covers the supplying, testing before shipment, painting, packing for transport, insuring, shipping, delivering to the port of Kenya, landing, customs clearing, transporting from the port to the site, erecting, constructing, installing, site pre-commissioning testing and commissioning of the plant works as generally described below.

Subsequent paragraphs will give detailed descriptions and requirements as to the plant specified herein.

33kV/11kv overhead lines Poles or other line support structures and associated materials Conductors and accessories Insulators Air break switches and fittings Stays and stay blocks

33kv /11kv substations Steel support structures and associated materials Switchgears and Control Equipment Control, Measuring and Protective relaying equipment. Surge arrestors 33kv/11kv line Tee-off from feeder Poles or other line support structures and associated materials Conductors and accessories Insulators Air break switches and fittings Surge arrestors 33/0.433 kV outdoor Equipment 25,50,100,200,315 KVA pole- mounted transformers Low voltage distribution board. Substation Building works. 11/0.433 kV outdoor Equipment 15,25,50,100,200,315 KVA pole- mounted transformers Low voltage distribution board. Substation Building works. Low voltage overhead lines Poles or other line support structures and associated materials. ABC cables and accessories. AA PVC conductor Stays and stay blocks.

Service cables

Cables and accessories.

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Cable trenches and slabs for three phase cables. Cut-outs.

1.2 DESCRIPTION OF THE PROJECT

As described under vol.1 Section VII 1.4 preamble.

1.3 STANDARDS Ratings, characteristics, tests and test procedures, etc. for the electrical equipment encompassed by this Specification shall comply with the provisions and requirements of the standards of the International Electro-technical Commission (IEC), and or KPLC operational standards unless otherwise expressly stated in Particular Technical Specifications. Where the IEC standards do not fully cover all provisions and requirements for the design, construction, testing, etc. and for equipment and components that are not covered by IEC Recommendations recognized national standards shall be applied.

The latest revision or edition in effect at the time of Bid Invitation shall apply. Where references are given to numbers in the old numbering scheme from IEC it shall be taken as to be the equivalent number in the new five-digit number scheme. The Bidder shall specifically state the Precise Standard, complete with identification number, to which the various equipment and materials are manufactured. The Bid Documents do not contain a full list of standards to be used, as they only are referred to where useful for clarification of the text.

1.4 UNIT OF MEASUREMENT AND LANGUAGE In all correspondence, in all technical schedules and on all drawings prepared by the

Contractor, the metric units of measurement shall be used. On drawings or printed pamphlets where other units have been used, the equivalent metric measurements shall be added. All documents, correspondence, drawings, reports, schedules instructions, and nameplate readings of the equipment shall be in the language stated in the Bid Data sheet.

1.5 SERVICE CONDITIONS From the geographical condition, the project area is categorized into the tropical climate zone.

In choosing materials their finishes, due regard shall be given to the humid tropical conditions under which the plant shall be called upon to work. The contractor shall submit details of his usual practice which have proven satisfactory and which he recommends for application to the parts of the work, which may be affected by tropical conditions. The materials and finishes used shall be approved by the Employer. All switchgear and control cubicles shall also be rodent and vermin proof.

1.5.1 Environment

Unless otherwise specifically stated in Particular Technical Specifications or Scope of Works, any equipment, component and assembly shall be designed for the following service conditions:

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Parameter Max Min Ambient air temperature Outdoor +40°C -1°C Indoor +40°C -1°C 24 hour average maximum +30°C -1°C Ambient temperature for cables in the ground +40 °C -1°C Relative humidity 90% Height above sea level 1800 m EMC Class (IEC 61000) Industrial environments Seismic coefficient 1.5 Wind pressure on project area of conductors and cylindrical objects

400 N/m²

Maximum wind pressure on steel members on 1.5 times projected area

820 N/m²

Rainfall conditions Average 800-1700 mm/year Maximum 160mm in 24 hrs Annual mean isokeraunic level Max 180 thunderstorm days Pollution (IEC 60815) Heavy :class II

Wherever any of these maximum or 24 hour average temperatures exceed the normal service condition temperatures of the IEC Recommendations for the relevant equipment, or of such other standard which is approved to be applied, the permissible temperature rises of the IEC Recommendations or the standard shall be reduced by the same amount as the difference between the above figures and the normal service condition temperatures. The Contractor shall guarantee these reduced temperature rises.

All air cooled equipment shall be cooled with convection (i.e. without fans) provided other cooling methods are not explicitly allowed for in the specifications.

1.5.2 Acoustics, Noise measurement The equipment shall as far as possible not generate undue vibrations or bothersome noise. Provided nothing else is specified the following requirements shall not be exceeded: Area of equipment location Maximum noise level dB(A) Machine hall, workshop etc. (one meter from the machine)

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Office, control room, day room etc 55 Emergency diesel generator (7 meter from engine room)

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1.5.3 Tropicalization

a) All equipment must be designed for operations in the severe tropic climate conditions and

fully comply with climatic aging tests as per IEC 60932-class 2.

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b) In choosing materials and their finishes, due regard shall be given to the humid tropical

conditions under which the plant will be called upon to work. Where it is not specifically called for, the contractor shall submit details of his usual practice which have proven satisfactory and which he recommends for application to the parts of the work, which may be affected by tropical conditions. The materials and finishes used shall be approved by the Employer. All switchgear and control cubicles shall also be rodent and vermin proof.

Enhanced description. (i) Metals:

Iron and Steel are generally to be painted or galvanized as appropriate. Indoor parts may alternatively have chromium or copper-nickel plates or other approved protective finish. Small iron and steel parts(other than rustles steel) of all instruments and electrical equipment, the cores of electromagnets and the metal parts of relays and mechanisms shall be treated in an appropriate manner to prevent rusting.

(ii) Screws, Nuts, Springs, Etc.

The use of Iron and steels shall be avoided in instruments and electrical relays wherever possible. Steel screws shall be zinc, cadmium or chromium plated or where plating is not possible owing to tolerance limitations, shall be of corrosion resisting steel. Instrument screws(except those forming part of a magnetic circuit) shall be of brass or bronze. Springs shall be of non-rusting material, e.g., phosphor-bronze or nickel silver, as far as possible.

(iii) Rubbers:

Neoprene and similar synthetic compounds, not subject to deterioration due to the climatic conditions, shall be used for gaskets, sealing rings, diaphragms, etc. TROPICALIZATION TO BE IN COMPLIANCE WITH

CLIMATE GRAPH NO. 8 OF THE IEC 721-2-1, TEST B: DRY HEAT IEC 68-2-2 TEST Bd; DAMP HEAT, CYCLIC IEC 68-2-30.

1.6 WORKING STRESS AND EQUIPMENT/APPARATUS DESIGN

1.6.1 General a) The design, dimensions and materials of all parts shall be such that they will not suffer

damage under the most adverse conditions nor result in deflections and vibrations, which might adversely affect the operation of the equipment. Mechanisms shall be constructed to avoid sticking due to rust or corrosion.

b) The equipment and apparatus shall be designed and manufactured in the best and most

substantial and workmanlike manner with materials best suited to their respective purpose and generally in accordance with up-to-date recognized standards of good practice.

c) All parts which will or might have to be dismantled for the purpose of serving or

replacement shall be assembled with anti-corrosive fasteners. The type, material and size

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of all fasteners shall be selected to safely withstand the maximum superimposed direct, alternating, kinetic and all loads induced by workmen when installing or removing the fasteners during the life of the equipment.

d) Suitable structural steel bases or frames shall be provided where necessary to transmit to

the concrete foundations all loads imposed by the various parts of the equipment. Such bases or frames shall be supplied complete with suitable anchor bolts and shall be so proportioned that the bearing loads imposed on the concrete foundations will not exceed 50kg per square centimeter.

e) The equipment shall be designed to cope with 0.15G acceleration of seismology on the

centres of gravity.

f) Whenever possible, all similar parts, including spare parts, shall be made interchangeable. Such parts shall be of the same materials and workmanship and shall be constructed to such tolerances as to enable substitution or replacement by spare parts easily and quickly.

g) All equipment shall be designed to minimize the risk of fire and consequential damage, to

prevent ingress of vermin, dust and dirt, and accidental contact with electrically energized or moving parts. The plant shall be capable of continuous operation with minimum attention and maintenance in the exceptionally severe conditions likely to be obtained in a tropical climate.

h) Upon request by the Employer complete information regarding the design assumptions,

loading and operating conditions, deflections and unit stresses used in the design shall be provided by the Contractor.

i) The Contractor shall be deemed to have examined the specification and drawings

herewith, and unless stated specifically to the contrary in the schedule of proposed conditions and /or deviations from the specification to have concurred with the design and layout of the applicable project features as being sufficient to insure reliability and safety in operation, freedom from undue stresses, adequate drainage and other essentials for a satisfactory working plant.

1.6.2 Strength and quality

a) All steel castings and weldings and all site weldings shall be stress-relieved by heat treatment before machining, and castings shall be stress-relieved again after repair by welding.

b) Liberal factors of safety shall be used throughout, especially in the design of all parts

subject to alternating stresses or shocks. 1.6.3 Design data low voltage equipment

Low voltage installation shall be designed in accordance with EMC directives. The rating and design criteria for low voltage equipment shall be as follows:

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a) AC system

Rated voltage between phase 415V Connection type 3ph 4wire Rated voltage between phase to earth 240V Grounding system PME Frequency 50hz Voltage variation +/-6% Frequency variation +/-2% Power frequency Test Voltage 1 min 3 kV Thermal rating of conductors 120 % of load Max short-circuit Current 25 kA

The three-phase supply shall be used for power circuit and the single-phase supply for lighting, indication, motor controls and similar small power circuits. The single phase supply within, cubicles and panels shall be transformed down to 110Volt AC if necessary. Unless otherwise specified, the equipment provided under this contract is to be capable of reliable operation at voltages as low as 85% of the rated voltage, and to withstand continuously upto 110% supply voltage above the rated value of 240V or 415V AC.

b) DC system

Rated voltage between phase 110V/30V dc Connection type 2 wire Voltage variation +/-6% Thermal rating of conductors 120 % of load Max short-circuit Current 25 kA

1) The Dc system shall be used for essential controls indication, alarm, protection relays, emergency lighting circuit breaker tripping and closing circuit.

2) All equipment and apparatus including protective relays and electronic equipment shall be capable of satisfactory operation at 80% to 125% of the rated supply voltage.

3) DC loads from the batteries/charger and associated MCB ratings shall be calculated by the contractor and the calculations results shall be submitted to the employer for approval.

4) The rating of the Station Auxiliary DC supply will be such that the station DC supply controlled operations will function normally for at least 10 hours following the loss of Auxiliary AC supply to the Battery Charger.

1.6.4 Design data High and medium voltage plant and equipment

The rating and design criteria for the HV and MV plant and equipment shall be as follows:

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Item Parameters SYSTEM PARAMETER System description 33 kV 11 Kv

1 System description 50 Hz, 3 phase, 3 wire 2 Neutral point earthing Solid earthed 3 Nominal voltage of networks 33 kV 11 kV 4 Highest system voltage as defined by

IEC-60038 36 kV 12 kV

5 3ph & 2ph Short circuit and earth fault current, symmetrical r.m.s. value (min breaking current) not less than

25 kA 25 kA

6 Thermal short-circuit current, not less than 3 second

25kA 25kA

7 Dynamic peak current (min making current)not less than

63 kA 63 kA

8 Rated current of busbars and bus coupler .

1250A 800A

10 Insulation level according IEC 60071: 10a Lightning impulse withstand voltage

(1.2/50 µs kVpeak) upto 1000m a.s.l for all external insulation

170kv

75 kV

Lightning impulse withstand voltage (1.2/50 µs kVpeak) at 1000m a.s.l for the whole equipment NB;-Some contracts have 2200 a.s.l

170kv 75kv

10c Test voltage at power frequency 1 min dry and wet. To earth and between phases upto 1000m a.s.l for all external insulation NB;-Some contracts have 2200 a.s.l

70kV

28 kV

Test voltage at power frequency 1 min dry and wet. To earth and between phases at 1000m a.s.l for the whole equipment. NB;-Some contracts have 2200 a.s.l

70kv 28kv

12 For the design and erection of the conductors for the lines, the following minimum clearances shall be observed

12a Phase to earth [mm] 480 300 12b Phase to phase [mm] 480 300 12c Live metal to oil pipe work (e.g in a

transformer) 480 300

12d Height to live parts above ground [mm]

2900 2 600

12e Height to live parts above ground at transformer transport routes [mm]

5000 5 000

12f Lowest part of insulators above ground [mm]

2 500

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Item Parameters SYSTEM PARAMETER System description 33 kV 11 Kv

13 Maximum temperature rise of conductors above ambient temperature (40 ºC)

40 ºC

14 Maximum wind pressure on conductors and cylindrical objects

430 N/m2

15 Maximum wind pressure on flat surfaces

820 N/m2

16 Minimum nominal creepage distance as defined in IEC 60815, Table II

25 mm/kV

Note 1) Ref IEC 60038, IEC 60071, IEC 60815 Note 2) Indoor equipment shall be arc tested in accordance with IEC 60298 amendment 2. The dynamic or momentary short circuit current on which the equipment design shall be based shall be computed by multiplying the r.m.s. value of the symmetrical short circuit current by the factor 1.8 x 2^0.5

Note 3) The next higher equipment rating shall be supplied during calculations for 2200 M altitude de-rating

1.7 BASIC REQUIREMENTS FOR ELECTRICAL EQUIPMENT

All materials supplied under this Contract shall be new and of the best quality and of the class most suitable for working under the conditions specified. They shall withstand the variations of temperature and atmospheric conditions arising under working conditions (including start and stop) without distortion deterioration or undue stresses in any parts and also without affecting the suitability of the various parts of the Works for which they were designed. The Plant shall be designed for a lifetime of 40 years. Equipment with a shorter life cycle shall be identified and so arranged that they are easy to replace.

1.7.1 Electrical controls, auxiliaries and power supplies

a) Responsibility for electrical control and auxiliaries.

The contractor shall provide all control, indication, alarm and protection devices and all auxiliary equipment with wiring and interconnecting cable which are integral parts of or are directly associated with or mounted on the equipment to be supplied under this contract.

b) Operation and control.

Interlocking devices shall be incorporated in the control circuit to ensure proper sequence and correct operation of the equipment.

1.7.2 Corona and radio interference

a) Switchgear shall electrically be designed to avoid local corona formation and discharge likely to cause radio interference.

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b) The design of all line conductor fittings, vibration dampers, insulator fittings, etc. shall avoid sharp corners or projections which would produce high electrical stress in normal operation.

c) The design of adjacent metal parts and melting surfaces shall be such as to prevent

corrosion of the contact surfaces and to maintain good electrical contact under service conditions.

d) Particular care shall be taken during manufacture of conductors and fittings and during

subsequent handling to insure smooth surface free from abrasion. 1.7.3 Insulators and fittings

a) All porcelain insulators and bushings for outdoor equipment shall be brown grazed and porcelain insulators. The resin insulators for indoor equipment may be of the inherent colour of the resin. All fittings shall be malleable iron hot-dipped galvanized alloy.

b) All the insulators and bushings shall have impressed thereon, before firing the glaze, the

name, initial or trade mark of the manufacturer, the year of manufacture and the mechanical strength.

1.7.4 Enclosure

a) The enclosures for switchgear, control and relaying equipment shall be dead-front, floor-standing or wall-mounting, rigid welded steel frames, completely enclosed by metal sheets and suitable for indoor or outdoor installation.

b) The completed sections shall have provisions for lifting and ample strength to withstand

all stresses incidental to shipping, installation and operation without distortion or other damage.

c) The floor-standing type enclosure shall be bolted at the bottom to suitable steel channel

and shall be of vermin-proof construction.

d) Suitable terminal blocks shall be provided for all outgoing power and control cables. All cable terminals shall generally be located for bottom entry and connections.

e) The enclosure shall be painted as specified under detailed specification for each

equipment.

f) Enclosures for electrical equipment shall have the following degree of protection (ref IEC 60034, IEC 60529 and IEC 60947):

Equipment Degree of protection Motors/Motor Terminal boxes IP 54/IP 65 Limit switches IP 65 Indoor switches IP 5x Outdoor switches IP 54 Outdoor switchgear IP 54 Out door marshalling kiosk IP 54 Indoor control and relaying equipment IP 51

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g) Interior illumination lamps operated by door switches shall be provided for each

enclosure. At least one 240V socket outlet of 3 point square shall be provided for each enclosure at a convenient location.

h) Space heaters for 240-volt A.C. shall be provided inside the enclosures to prevent

moisture condensation. A hygrostat control unit with variable temperature and humidity control shall be installed to control the heater.

1.7.5 Measuring instruments

a) All measuring instruments, including energy meters, shall be of flush-mounted, back-

connected, dust-proof and heavy-duty switchboard type. Each measuring instrument shall have a removable cover, either transparent or with a transparent window. Each instrument shall be suitable for operation with the instrument transformers shown on the drawing under both normal and short-circuit conditions.

b) For analog type instruments, scale plates shall be of a permanent white circular or

rectangular finish with black pointer and markings. The scale range shall be determined from the current transformer and voltage transformer ratios. Where double ratios are specified, both scale plates shall be supplied or alternatively the same plate to have both ranges on either side inscribed.

c) All measuring instruments of analog type shall be approximately 110mm2 enclosures and

shall be provided with clearly readable long scale, approximately 240 degrees. The maximum error shall be not more than one and a half (1.5) percent of full-scale range.

1.7.6 Indicating lamps

a) Indicating lamp assemblies for the enclosures shall be of the switchboard type, insulated for30-volt D.C. service, with appropriately colored lens and integrally mounted resistors for 30-volt service. The lens shall be made of a material, which will not be softened by the heat from the lamps.

b) Red indicating lamps shall be used for “ON” position, green lamps for “OFF” position

and Amber for Transition . 1.7.7 Nameplate and Escutcheon Plates

a) Nameplates and Escutcheon Plates Each cubicle, panel, meter, switch and device shall be provided with a nameplate or

escutcheon plate for identification with both IEC Numbers and English description. Each equipment shall be provided with a rating plate containing the necessary information specified in the relevant IEC standards.

b) The plates shall be made of weatherproof and corrosion-proof materials and shall not be

deformed under the service conditions at the site. The entries on the plates shall be indelibly marked by engraving to black letter on a white background. The language of all plates shall be English.

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1.7.8 Wiring

a) General i) All wiring inside the switchboards shall be done with PVC insulated wire not less

than 2.5 sq.mm flexible cable except for electronics devices. A suitable wiring duct system shall be installed for all inter-panel and front-to-rear panel wiring which will provide easy access for inspection and replacement. As far as possible all wiring shall be installed in wiring ducts.

ii) Wiring between terminals of the various devices shall be point to point. Splices or

tee connection will not be acceptable. Wire runs shall be neatly trucked or clamped. iii) Exposed wiring shall be kept to a minimum, but where used shall be formed into

compact groups suitably bound together and property supported. iv) Instrument transformer secondary circuits shall be grounded only at the first panel

entered, and shall not be grounded at any point or outside of the enclosures. v) Cable supports and clamp type terminal lugs shall be provided for all incoming and

outgoing power wiring terminated at each panel. All wire shall be marked near each terminal end with circuit or wire designation. These markers shall be of an approved type and permanently attached to the conductor insulation. The method of ferruling shall be subject to approval by the Employer

vi) All cables shall have 25 % spare wires for future use.

b) Phase arrangement The standard phase arrangement when facing the front of the panel shall be R-S-T-N, and P-

N from the left to right, from top to bottom, and front to back for A.C three-phase and single-phase circuits. For DC circuit it shall be N-P from left to right, P-N from top to bottom and front to back . All relays, instruments, other devices, buses and equipment involving three-phase circuit shall be arranged and connected in accordance with the standard phase arrangement where possible.

(c) Wiring colour code

All wires shall have ferrules at all terminations to distinguish each terminal. In addition, the wire shall have the following colours:

Circuit Colour Voltage transformers/ Current transformers R, Y, B, BLK A.C. Circuit R or Y or B and BlK D.C. Circuit s Grey. Auxiliary D.C supply R & Blk Grounding circuit Green with yellow stripe

(d) Phase and polarity colour code Following coloured ferrules shall be provided on each wire in order to identify phase and polarity.

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Phase and Polarity Colour A.C., three-phase, First phase Red

Second phase Yellow Third phase Blue Neutral Black

A.C., single-phase, First phase Red Second phase Yellow Neutral Black Ground Green with yellow stripe

Auxiliary Supply Positive Red Negative Black

Cable markers and wire Numbers system must be submitted to the Employer for approval before commencing the works.

1.7.9 Terminal blocks

a) Terminal blocks for control wiring shall be rated not less than 600V AC .

b) White or other light-coloured marking strips, fitted to each block, shall be provided for circuit designation.

c) The terminal arrangement, including the terminal blocks for VT and CT circuit

connections, shall be subject to the Employer’s approval. 10 % Spare marking strips shall be furnished with each block.

1.8 EARTHING SYSTEMS, ELECTRODES AND CONNECTIONS 1.8.1 GENERAL

The earthng for all equipment and the provision of earthing systems, electrodes and connection shall be in accordance with the recommendations in the “Guide for safety in substation grounding” ANSI/IEEE No. 80 – 1986 and the requirements of British Standards BS 6651, BS 7430 and this Section.

1.8.2 EXTENT OF WORK

The work under this section comprises the design, supply and installation of earthing systems and connection to all electrical apparatus supplied under this contract. Also included is the provision of portable earthing devices. The contractor will be required to prepare installation drawings and schedules of material to be provided. These drawings and schedules shall be submitted to the Employer for approval together with calculations of step, touch and mesh potentials.

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1.8.3 DESIGN OF EARTHING SYSTEMS i) General

New sites shall be provided with an earth grid of buried conductors designed for an earth fault current of 25 Ka for 1 second. The preliminary design shall be such that the potential rise shall not exceed 5k V. The contractor shall submit his preliminary design for the earthing systems for approval by the Project manager. This shall include measurement of soil resistivity , calculations of resistance, potentials and current ratings for current flowing into or out of the ground. Step and touch voltages both inside and outside the station shall not exceed 313V and 885V respectively assuming a crushed stone surface with a resistivity of 3000 ohm-meteres, and a maximum exposure time of 0.5 seconds. The earth shall also be connected by 95 mm copper conductor to the earthwires of overhead lines and to the terminal structures . Earthing points shall be provided such that the combined resistance of the earth grid and all other earthing points does not exceed one (1) ohm under any climatic condition.

1.8.4 CONSTRUCTION OF EARTH GRIDS

The earth grids shall be of high conductivity copper conductor, area not less than 200sq mm and shall be installed by the Contractor at a 500mm depth. Any excavation and back filling necessary will be carried out by the Contractor and installation of the earth grid shall be carried out to suit the civil works program.

1.8.5 EARTHING POINTS.

The number of earthing points necessary shall be verified by site earth resistivity tests after the letting of the contract. Earthing points: each shall consist of not less than four and not more that eight 15mm diameter copper rod electrodes, each 3.5 meters and driven or drilled into undisturbed ground at spacings of not less than the length of the rods. Each electrode shall be complete with approved non-ferrous clamps for the connection of earthing conductors and with a hardened steel tip and cap for driving by means of a power hammer. Test link chambers and covers for each point shall be provided and a drawing showing the proposed arrangement shall be submitted by the contractor for approval . Locations for the electrode chambers and the interconnection arrangement shall be approved by the Engineer when the results of the site earth resistivity tests are known.

1.8.6 CONNECTION OF EARTHING POINTS AND SYSTEM NEUTRALS

The electrodes of an earthing point shall be arranged in two groups with a conductor from each group to the test link and there shall be duplicate conductors from each test link to the earth grid. Each connection to the earth grid shall be at a link chamber adjacent to the grid

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with two conductors from the grid connected to one terminal. Where the electrode groups are close to the grid the group connection can be made directly to a link chamber at the grid. Any neutral points for high voltage systems within a substation shall have duplicate connections to the closest link chamber(s) of an earthing point(s). Conductors interconnecting the electrodes to a test link and between the tests links and the earth grid shall have a cross-sectional area or not less than 95sq. mm copper. There shall be at least two such connections from each link to the electrodes and to the earth grid. Duplicate connection may be in the form of rings. Earthing conductors shall be of annealed high conductivity copper stranded in accordance with Table 4 in BS.6346 and protected with an extruded PVC sheath of 1000 volts grade. Earthing conductors shall normally be buried directly in the ground but where necessary they may be cleated to walls, fixed to cable racks or laid in the cable trenches as convenient.

1.8.7 EARTHING OF EQUIPMENT.

The frames of all electrical apparatus and the bases of all structural steelworks shall be connected by branches of the same cross section area to the earth grid or to subsidiary branches running to a group of equipment. All disconnector bases, earth terminals and earthing switches, neutral current transformers, power transformers, surge arrester bases and towers and gantries on which overhead earth wires are terminated shall be connected to the earth grid. Surge arrester installed for the protection of transformers shall be connected by direct low reactance paths both to the transformer tank and the earth grid. Capacitor voltage transformers used in connection with line traps shall be connected by direct low reactance paths to a single earth rod in addition to the earth grid. Where station fences are in un-insulated metallic material, they shall be connected to the earth grid at all supporting posts and to a 35 sq. mm copper conductor buried in 1m outside the fence at a depth of 500mm. Disconnector and earthing –switch operating mechanisms and circuit breaker control kiosks not integral with the circuit breaker shall be connected to the earth system by a branch entirely separate from that employed for earthing the Disconnector, earthing-switch or circuit breaker structure. Such branches shall be connected to a ground mat which shall be provided beneath the position where an operator will stand. Galvanized steel structures with sufficient area and current carrying capacity may be used as part of the earth connection to post and strain insulators and to overhead earth conductors which shall be terminated directly on the steel works.

Buildings containing electrical equipment shall be provided, at each level, with a ring of earthing conductors which shall have duplicate connections to the earth grid outside the building. The frames of all switchgear, control and relay panels and other electrical equipment and exposed structural metal work shall be connected by branches to a ring. The ring and branch conductors shall be of the same material as the earth grid.

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Strip run within buildings, inside cable trenches or above ground level apparatus shall be neatly supported in non-ferrous clamps.

1.8.8 JOINTING AND BONDING

Connections to plant and equipment shall be made using the earthing terminals specified in the contract. Where a strip has to be drilled to fit an earth terminal the diameter of the hole shall not be greater than a quarter the width of the strip. Stranded earthing conductors shall be terminated with sweated or crimped cable lugs.

1.8.9 MV LINE EARTHING

On 33kV lines where aerial earthwire is to be provided, metalwork on every pole is to be bonded and connected to the earthwire. The earthwire shall be connected to earth at every 4th span. The resistance of the aerial earthwire with earth shall not exceed 0.2 ohm per kV of line voltage.

1.9 MATERIALS AND WORKMANSHIP 1.9.1 General

a) Materials shall be new; the best quality of their respective kinds and such as are usual and suitable for work of like character. All materials shall comply with the latest issues of the specified standard unless otherwise specified or permitted by the Employer.

b) Workmanship shall be of the highest class throughout to ensure reliable and vibrations

free Operations. The design, dimensions and materials of all parts shall be such that the stresses to which they may be subjected shall not cause distortion, undue wear, or damage under the most severe conditions encountered in service.

c) All parts shall conform to the dimensions shown on and shall be built in accordance with

approved drawings. All joints, datum surfaces and meeting components shall be machined and all castings shall be spot faced for nuts. All machined finished shall be shown on the drawings. All screw, bolts, studs and nuts and threads for pipe shall conform to the latest standards of the International Organization for Standardization covering these components and shall all conform to the standards for metric sizes. The Contractor shall never incorporate any standards or size system by his own account, regardless of that accepted and incorporated in this Contract.

d) All materials and works that have cracks, flaws or other defects or inferior workmanship

will be rejected by the Employer. All defective materials shall be promptly removed from the site by the Contractor, and inferior workmanship shall be cut out and replaced.

1.9.2 Standard Specifications The design, materials, manufacture, testing, inspection and performance shall, unless

otherwise specified in the Special requirements of these Specifications, conform to the authorized standards of the International Electrotechnical Commission (IEC) or equivalent

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national standards in additional to KPLC Operational procedures. The Contractor shall include a statement of the standards, intended to be used.

1.9.3 Assembly

Necessary items of equipment shall be assembled in the factory and/or site prior to shipment

and type tests shall be performed by the contractor as may be required to demonstrate to the satisfaction of the Employer the adequacy of equipment and its component parts. All tests should simulate normal operating conditions as closely as possible. All dismantled parts shall be properly match marked and doweled to ensure correct assembly in the field.

1.9.4 Casting

a) Casting shall be true to pattern, of workmanlike finish and of uniform quality and

condition, free from blowholes, porosity, hard spots, shrinkage defects, cracks or other injurious defects, shall be satisfactorily cleaned for their intended purpose.

b) Major defect on castings shall not be repaired, plugged, or welded without permission of

the Employer. Such permission will be given only when the defects are small and do not adversely affect the Strength, use or merchantability of the castings. The Contractor shall give the distinction between major and minor defects. Excessive segregation of impurities or alloys at critical points in a casting will be a cause for its rejection. The largest fillets compatible with the design shall be incorporated wherever a change in section occurs. All castings shall be stress-relieved before machining and again after repair by welding.

c) Plates to be joined by welding shall be accurately cut to size and rolled by pressure to the

proper curvature, which shall be continuous from the edges. Flattening in the curvature along the edges with correction by blows will not be allowed. The dimensions and shape of the edges to be jointed shall be such as to allow thorough fusion and complete penetration, and the edges of plates shall be properly formed to accommodate the various welding conditions.

1.9.5 Forging

a) The ingots from which the forgings are made shall be cast in metal moulds. The workmanship shall be first-class in every respects and the forgings shall be free from all defects affecting their strength and durability, including seams, pipes, flaws, cracks, scales, fins, porosity, hard spots, excessive non-metallic inclusions and segregations.

b) The largest fillets compatible with the design shall be incorporated wherever a change in

section occurs. All finished surfaces of forgings shall be smooth and free from tool marks.

c) The forging shall be clearly stamped with the heat number in such locations to be readily

observed when the forging is assembled in a completed unit.

1.9.6 Welding

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a) Wherever welding is specified or permitted by the project Manager, a welding process, including stress relieve treatment as required if necessary, conforming to an appropriate and widely recognized professional standard shall be used. All welders and welding operators shall be fully qualified by such a standard.

b) After the welding process has been approved by the Employer, the Contractor shall record

it on a special drawing, which shall thereupon become one of the drawings of the Contract.

c) Radiograph inspection shall be carried out by the Contractor when required by the

standards, Specifications, or the design criteria employed. All welds which, in the opinion of the Employer, may be subject to the full stress induced in the adjacent plate, or which in the opinion of the Employer, do not appear to conform to the welding standard shall be radiographed when required.

d) All defects in welds shall be chipped out to sound metal and such areas shall be

magnetically or ultrasonically tested to ensure that the defect has been completely removed before repair welding.

e) Plates to be joined by welding shall be accurately cut to size and rolled by pressure to the

proper curvature, which shall be continuous from the edge. Flattening in the curvature along the edges with correction by blows will not be allowed. The dimensions and shape of the edges to be jointed shall be such as to allow through fusion and complete penetration, and the edges of plates shall be properly formed to accommodate the various welding conditions.

f) The surfaces of the plates adjacent to the edges to be welded shall be thoroughly cleaned

of all rust, grease and scale to bright metal. All important welding shall be stress-relieved by heat treatment before machining.

1.9.7 Galvanizing

a) Unless specifically mentioned to the contrary, iron and steel shall be galvanized in the

factory after fabrication. The zinc coating shall be uniform, clean, smooth and as free from spangle as possible. Galvanizing shall be applied by the hot dip process for all parts other than steel wires. All steel wires shall be galvanized by a recognized trade standard.

b) The minimum quantities of zinc coating shall be 350 gram/sq. metre for bolts and nuts

and 550 gram/sq. Metre for all other parts except steel wires, unless otherwise specified in the Contract Documents. The uniformity of zinc coating, tested by dipping surface shall be exposed until the surface has been dipped four times for bolts and nuts, and six times for all parts.

c) The preparation for galvanizing and the galvanizing itself shall not distort or adversely

affect the mechanical properties of the materials.

d) Special treatment during galvanizing to prevent the formation of “White rust” during shipment or storage is required. The Tenderer shall state in his Tender the treatment to be used.

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1.9.8 Colour standard

The final colour of each item shall be as described under each item.

1.9.9 Nameplate a) To facilitate operation and maintenance it is very important that all equipment e.g, valves,

instruments, switches, pipeline, etc., shall be clearly identified by nameplates showing the function and proper use of each item. Such identification shall be in English and must be intelligently and carefully designed to minimize errors and to avoid maloperation in operation or maintenance.

b) The nameplates shall be permanently legible, clearly worded, weather proof when

outdoors and securely mounted in conspicuous and logical locations. Outdoor equipment labeling shall be legible from the ground.

c) A table showing materials, dimensions, location, mounting and wording shall be

submitted to the Employer for approval.

1.9.10 Building cabling and wiring a) The conductor used in substation and switching station shall be continuous between

outlets, and no junction shall be made except within outlets or junction boxes. The conductor shall be drawn through ducts or conduits after they have been cleaned. Oil or grease shall not be used as a lubricant for the drawing operation, but an approved compound may be used for this purpose.

b) Rigid steel conduit shall be galvanized inside and outside, or enameled inside. It shall be

of a minimum thickness of 2.3 millimetres and have a minimum inside diameter of 16 millimetres.

c) Conduits shall be concealed within the walls, ceilings and floors where possible.

Exposed runs of conduit shall be supported within a space of not more than 150 centimetres.

d) Conduits shall be installed perpendicular to walls, structural members and ceilings.Only

threaded joints shall be used. Conduit, which are crushed or deformed, shall not be used in the works.

e) Conduit shall be installed in such a manner as to ensure that the inside remains in a dry

condition. Conduit shall be securely fastened to all sheet-steel outlets, junction and pull boxes with galvanized locknuts and bushings.

f) Exposed conduits shall be finished with the same colour paints as the finished colour of

the wall or ceiling against which the conduits are placed.All joints and terminations shall comply with the weatherproof or explosion proof requirements as applicable.

1.10 SAFETY PRECAUTIONS

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a) Prior to any of the work being energized, the Contractor shall be responsible for supplying and fixing in prominent positions near to each item of the work concerned, large temporary signs giving clear warning of danger in areas which might previously have been regard as safe.

b) During erection and tests the Contractor shall provide all temporary scaffolding ladders,

platforms with toe boards and handrails as required for safe and convenient access of workmen, inspectors and other authorized persons. All dangerous opening or holes shall be provided with handrails or covers. Measures shall be taken to protect workmen from falling. The maximum possible safety shall be afforded to personnel directly engaged on this Contract or to those who frequent the working area or to those who in the normal course of their occupation find it necessary to utilize temporary works erected by the Contractor.

c) The Contractor shall demonstrate that he has facilities and personnel for conducting a

safety programme commensurate with the works on the site. He shall submit in writing a proposed comprehensive safety programme to the Employer for approval prior to the start of construction operation on the site. The Contractor shall designate a competent safety officer to carry out his safety programme as per Vol 1 on personnel.

1.11 PROTECTION, CLEANING AND PAINTING 1.11.1 Embedded steelwork

All parts to ultimately be buried in concrete shall be cleaned and protected before leaving the manufacturer’s plant by cement wash or other approved method. Before being installed they shall be thoroughly desiccated and cleared of all rust and adherent matter, or be treated according to a method approved by the Employer. Such cleaning or treatment shall not detrimentally affect the strength or final operation and function of the equipment.

1.11.2 Steel exposed to atmosphere .

a) All machined parts or bearing surfaces shall be cleaned and protected from corrosion before leaving the manufacturer’s plant by the application of an approved rust preventive coating, or a peelable plastic film. Where the latter is impracticable, such parts shall be heavily covered with high melting point grease. After erection such parts shall be cleaned with solvent and lapped or polished bright.

b) All parts, other than machined parts, which will be exposed after erection shall be

thoroughly cleaned and galvanized or given with two coats of best quality approved primer and one coat of best quality approved finish paint before leaving the manufacturer’s plant and a further one coat of paint of an approved quality and colour after erection and touching up on the site, expect such apparatus as panels and instruments which shall be finished painted under approved procedures.

c) All outside panel surfaces shall be primed, filed where necessary, and given not less than

two coats of synthetic undercoat. The finishing coat for the outdoor and indoor installations shall be a gloss paint.

d) Primer shall be applied to surfaces prepared in accordance with the plant manufacturer’s

instructions. The surface shall be wiped clean immediately prior to applying the paint.

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The primer and finish coats of paint shall be applied using the methods and equipment recommended by the manufacturer.

e) The internal surface of all pipelines shall be cleaned out by the approved methods before

installation and again prior to commissioning, to ensure freedom from dirt, rust, scale, welding slag, etc. all exposed pipes shall be painted with an identifying colour after erection is completed. The colour code system shall be approved by the Employer.

f) All steel surfaces, which are in permanent contact with oil, shall be given three coats of

approved oil resistant.

g) No painting or protection is required for finished or unfinished stainless steel parts.

h) The final colour of all equipments, frames for meters and relays, and switch handle shall be as described under each particular item.

i) The humid and tropical conditions shall be taken into account on selection of the paints

and painting procedure.

1.12 EMBEDDED METAL WORK, OPENING, ETC

a) The Contractor shall supply and install all enters, fasteners, embedded metalwork’s, piping, conduit and sleeves associated with and required for the equipment being provided and installed under this Contract, except as otherwise provided in the specifications.

b) The Contractor shall indicate the location and details of foundations, openings, block-out

and all embedded components on his drawings and shall be responsible for the completeness and accuracy of his drawings and the information supplied to others. The Contractor shall be responsible for the adequacy and accuracy of location of all embedded components supplied by him.

c) The foundation bolts, embedded steel parts, anchors, braces, posts, supports, shims, etc.,

and all metal works as may be required for temporary or final support of anchorage of the equipment shall be provided and installed by the Contractor as part of this contract.

d) Any metal work, which is to be built into the concrete foundations, shall not be painted

nor coated unless otherwise approved. 1.13 SPARE PARTS

a) The Contractor shall furnish spare parts as listed under each particular item. Other mandatory spares shall be provided as listed in the price schedules.

b) The spare parts supplied shall be packed or treated in such a manner as to be suitable for

storage under the climate conditions at the Site for a period of not less than two years, and each part shall be clearly marked with the description and purpose on the outside of the package. The manner of storage shall be recommended by the Contractor.

c) Spare parts so provided shall be delivered into such stores as may be designated by the

Employer. Delivery of spare parts will not be deemed to be complete until the packages have been opened by the Contractor, their contents checked by a representative of the

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Employer and the articles reprotected and repacked by the Contractor to the satisfaction of the Employer, or assembled into units at the employer’s option. The method of package and package materials shall be suitable for the satisfactory re-package.

d) The Contractor shall supply the net quantities plus 5% of all permanent bolts, screws and

other similar items and materials required for installation of the works at the site. Any such rivets, bolts, screws, etc., which are surplus after the installation of the equipment has been completed shall become spare parts and shall be wrapped, marked and handed over to the Employer.

1.14 PACKING

a) Each item shall be packed properly or protected for shipment from the place of

manufacture to the site. b) Each crate of package shall contain a packing list in a waterproof envelope and a copy in

triplicate shall be forwarded to the Employer prior to dispatch. All items of material shall be clearly marked for easy identification against the packing list.

c) All cases, packages, etc, shall be clearly marked on the outside to indicate the total

weight, to show where the weight is bearing and the correct position of the slings and shall bear an identification mark relating them to the appropriate shipping documents.

d) Cases, which cannot be marked as above, shall have metal tags with the necessary

marking on them. The metal tags shall be securely attached to the package with strong steel wire or equivalent.

e) Long pieces of steel angles shall be packed in bundles and properly tied together by an

approved method and care taken to ensure that they are robust and not of excessive length and weight for handling in transit.

f) Short pieces of steel angles and steel plates shall be bolted or wired together through

holes and packed in stout timber cases.

g) Bolts, nuts, washers and fillers shall be bagged in sealed vinyl and packed in steel cans. The cans shall bear the contents and be crated together.

h) Packing together of components of dissimilar metals shall not be acceptable.

i) Conductors and overhead earthwire shall be packed on drums stoutly constructed of good

quality wood. Drums shall be securely battened around the perimeter to give maximum protection to the conductor and the earthwire and correct direction of rolling indicated with an arrow in a manner not easily removable and the length of the conductor.

j) The first layer of conductors or earthwire on drums shall be secured to the hub in manner

avoiding damage to subsequent layers.

k) All drums shall be protected from deterioration on site by termite or fungus attack by an approved impregnation treatment at the works before dispatch.

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l) The Employer shall reserve the right to inspect and approve the equipment and the packing before the items are dispatched. The Contractor shall be entirely responsible for ensuring that the packing is suitable for transit and such inspection will not relieve the Contractor from responsibility for any loss or damage due to faulty packing.

m) It shall be the responsibility of the Contractor to improve and to reinforce the road

facilities when the weight and dimension of the cargo exceed the above specification. All packing materials except all drums shall remain the property of the Contractor

and shall be removed from the Site at the earliest opportunity and disposed off to the satisfaction of the Employer.

(a) Consignee: COMPANY NAME

(b) Name of Project: (33KV, 11KV AND 0.433KV LINES AND SUBSTATIONS FOR R.E TURNKEY PROJECTS)

(c) Contract No.: KPLC/RE/Turnkey/1-C-2006 (d) Port of destination: MOMBASA (e) Item Number, if applicable, Package number in sequence, and quantity per package: ………………………………………………. (f) Description of Contents: ……………………………………………… Net and gross weight, cubic measure: ………………………………… The shipping mark is finally subject to the Employer’s approval.

1.15 DELIVERY

a) The Contractor shall deliver all materials and equipment including Contractor’s

equipment supplied under the Contract to the site in adequate time for its preparation and erection according to the Schedule.

b) Each notification shall include a complete shipping list of the contents of each package to

be delivered and shall indicate the anticipated date of delivery and the serial number for each component to be used for identification and evidence of the insurance cost arranged for it. The contractor shall notify the Employer of goods arrival at site in good time for inspection with relevant store documents attached

c) The Contractor shall be responsible for the reception on Site of all deliveries for the

purpose of the Contract.

1.16 CLEANING AND MATERIAL DISPOSAL

The Contractor shall at all times during the course of the work prevent the accumulation on the premises of debris caused by the Works. Whenever it is necessary, in the opinion of the Employer and in all events upon completion of the Works, the Contractor shall remove from the premises all temporary buildings and facilities, tools, scaffolding, surplus materials,

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debris and all work and materials condemned by the Employer and shall leave the premises in a clean, safe and sanitary conditions. The Contractor shall prevent at any time unnecessary accumulation and scattering of debris, materials, tools and equipment around the premises, and shall conduct the work in an orderly manner. In case the Contractor fails to comply with the above provision, or in case of dispute, the employer shall have the RIGHT to order removal by others of debris, materials, tools or equipment, and to charge the cost of such removal and/or repairs to the Contractor. All Cable drums, replaced poles and oil Drums shall be returned to KPLC Regional stores.

1.17 PROGRAMME AND PROGRESS a) Within one month after the Date of Commencement or contract signing, the Contractor

shall prepare his construction program in a Software form covering the design, manufacture, delivery, erection testing and commissioning of the Works, in sufficient detail to define the various tasks of the Works, including parts to be supplied by the Contractor. A Soft and hard copy shall be submitted to the Employer for approval.

b) Upon approval of the program by the Employer, it should thereafter be referred to as the

approved Construction Program and shall become a part of the Contract.

c) Monthly progress reports shall be provided by the Contractor, indicating the actual state of progress of all items during the course of manufacture and work at the Site, in the form given by the Employer.

d) A brief weekly report covering the following week on the construction work at the Site

shall also be submitted by the Contractor to the Employer.

e) From time to time during the execution of Contract, the Employer is empowered to call meetings, either in his home office or at the manufacturer’s offices or Employer’s Nairobi office or at the Site, as he deems necessary, for the purpose of co-ordination and control. The employer is required to call regular meetings or any other meeting in addition to the monthly meetings. If required by the Employer, responsible representatives of the Contractor shall attend such meetings at his own expense.

f) In executing the Approved Construction Program of this Contract, the Contractor shall

co-operate with the Employer and other contractors on the Site in order to effect the timely completion of the Project as a whole.

1.18 DRAWINGS AND DATA TO BE SUPPLIED BY THE CONTRACTOR a) Before starting manufacture of the equipment, dimensioned drawings and data showing

all significant details of the equipment and materials to be used shall be submitted to the Employer for approval, at least 3 weeks before the commencement of the manufacturing process.

b) These drawings shall be submitted within the times mentioned hereunder, measured in

calendar month from the Date of commencement. The drawings shall be modified as necessary if requested by the Employer, and resubmitted for final approval.

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c) When the Contractor prepares his construction schedule, as required herein, he shall make allowance for the drawing approval time and indicate it on the schedule. A period of at least two(2) weeks shall be allowed for such approval after receipt by the Employer. Claims or extensions of time will not be approved if they are related to the late submission of drawings to the Employer or if they involve delays caused by drawings not being approved by the Employer.

d) After approval of drawings by the Employer, the Contractor shall supply the approved

drawings to the Employer according to the table given below.

e) If after the said 2 weeks the employer has not approved the drawings, the Contractor will notify the employer in writing and proceed with the manufacturing process.

f) The contractor shall also give the Employer at least one(1) weeks notice for progress of

work inspection and or material inspection at site

g) It is to be understood, however, that approval of the drawings will not relieve the Contractor of any responsibility in connection with the work.

h) All drawings submitted for approval or sent to the Employer for any other reason shall be

sent by courier.

i) After items of the work have been manufactured and erected, complete sets of prints and negatives of the finally corrected drawings shall be furnished according to the following table.

To the Employer During the work Drawing for approval 3 copies Approved drawings 3 copies After completion of the work (final drawings) AutoCad (latest version) 2 Cds Complete set of bound prints (as built) 3 sets 33KV, 11kV and 0.433 KV lines: -Pole schedules Additional copies of particular Network drawings from the employer related to the contract are to be provided if required, at the Contractor’s expense.

1.19 OPERATING AND MAINTENANCE INSTRUCTIONS a) The Contractor shall submit to the Employer for approval, general instructions concerning

the correct manner of assembling, operating and maintaining the work. This instruction manual shall be submitted immediately following final approval of the drawings.

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b) When finally approve, Four (4) copies of the instruction manual shall be furnished to the

Employer. The contractor shall ensure that his erection supervisor has a copy in his office at the Site.

c) The instruction manual shall describe in detail the erection procedure and use of all

erection equipment and measurement devices. The method for assembling, adjusting, operating and dismantling of each device, system and machine shall be described and illustrated. The maintenance details of each component shall also be described, including the frequency of inspections and lubrication.

d) The instruction manual shall include a separate and complete section describing the

normal and emergency operating procedures for the control of the switching equipment, and shall include explanatory diagrammatic drawings of equipment to facilities understanding the description.

e) The Contractor shall, in preparing the instruction manual, take into account the lack of

experience and familiarity of the operators with this type of equipment.

f) The manual shall give specific information as to oil, grease, or any other materials needed for maintenance operations. This information shall include brand names and manufacturer’s numbers or designations, for at least two brands available in Kenya, preferably manufactured in Kenya.

g) The manual shall include a complete list of all drawings prepared for the Contract, spare

parts list, and a parts list for each component of the equipment. The parts list shall apply only to the equipment supplied and shall not include general reference or description of similar equipment which is of the same model but different only in detail. The manual shall be prepared on the English language.

1.20 TEST PROCEDURES AND INSTRUCTIONS

a) The Contractor shall prepare and execute a testing program which will establish that specified requirements have been met and that the items furnished and installed will perform as specified and required.

b) The Contractor shall submit to the Employer for approval, during or immediately

following the submission of drawings, testing program describing each test to be performed during commissioning and performance tests. The program shall establish the sequence of the test, the equipment preparation and operation procedures to be followed and the detailed procedure for conducting each test. The program shall also contain performance guarantees, design values, technical particulars, or other criteria and distributed in the same manner as the drawings.

c) A file containing a list of all the Pre-commissioning Tests carried out on all the

equipment and Protection and Control schemes and the primary equipment, including system balanced and unbalanced fault analysis for relay coordination and scheme settings shall be submitted to the Employer prior to the commissioning of the project. It is

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mandatory that these group tests shall be witnessed and signed by the Employer’s representative.

d) Three copies of the Pre-Commissioning Report shall be submitted to the Employer.

1.21 EQUIPMENT TESTING AT PLACE OF MANUFACTURE

a) The manufacturers shall be responsible for performing or for having performed all the required tests specified under the specification for all the equipment . Tenderers shall confirm the manufacturer’s capabilities in this regard when submitting tenders. Any limitations shall be clearly specified.

b) Tender documents shall be accompanied by copies of Type test and Routine test

reports & certificates for similar rated equipment as requested for the purpose of tender evaluation Type Tests Reports shall be carried out by a laboratory independent from the manufacturer or with the witness of independent laboratory. Current contact information of the testing and certification authority shall be provided.

c) Upon completion of the manufacturing process, routine tests shall be carried out as

per the respective standards of each equipment and the results endorsed by the NSTA of the country of manufacture.

d) The Contractor shall arrange for the Employer’s staff members to witness tests of

major items of equipment in the manufacturer’s plant as follows:

e) Where required, the equipment mentioned above shall be subjected to inspection by

two KPLC Engineers or her representative at place of manufacture for 5 days per equipment and all routine tests and other tests specified under each specification carried out in their presence. KPLC representatives shall approve shipment of the equipment if they are satisfied that the requirements of the specification are fully met. The supplier shall quote separately as in Vol 1 for these inspections. The full cost of the visit, including air tickets, and accommodation shall be borne by the supplier of the equipment

1.22 PHOTOGRAPHS

a) The Contractor shall keep photographic records of the progress of each phase of the work. The determination of each particular phase shall be agreed upon between the contractor and the employer after contract signing. Upon completion of the work, the Contractor shall submit three sets of colour photographs or a CD with explanatory description adequately edited in book form to the Employer’s satisfaction.

b) The Contractor shall provide himself with necessary access to the work and temporary

facilities to photograph his part of the work at any stage of construction or manufacture.

2 TECHNICAL SPECIFICATIONS FOR SUBSTATION EQUIPMENT 2.0 DISTRIBUTION TRANSFORMERS

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2.0.1 SINGLE PHASE DISTRIBUTION TRANSFORMERS 2.0.1.1 SCOPE a) This specification is for oil – immersed, air – cooled single phase distribution transformers

for 11kV and 33kV distribution system operated at 50 Hz. b) This specification covers transformers of the following voltage ratios and ratings.

(i) 11000/250 volts single phase distribution transformer;- 5KVA, 15 KVA and 25 KVA (ii) 33000/250 volts single phase distribution transformer;- 25 KVA

2.0.1.2 REFERENCES The following documents were referred to during the preparation of this specification, in case of

conflict the requirements of this specification take precedence. BS 137: Insulation of ceramic material or glass for overhead lines with a nominal voltage greater than 1000V. 2.0.1.3 TERMS AND DEFINITIONS For the purpose of this specification, the definitions in IEC 60076 shall apply.

2.0.1.4 REQUIREMENTS 2.0.1.5 SERVICE CONDITIONS

2.0.1.5.1 Operating conditions The transformers shall be suitable for continuos operation in tropical areas with the following

atmospheric conditions.

(a) Altitude: From sea level up to 2200m above mean sea level.

(b) Humidity: Polluting saline atmosphere and where humidity is 90%.

(c) Ambient temperatures of +30 C average, (+40 C Max. and -1 C Min).

(d) Isokeraunic value: 180 thunderstorm days per year

2.0.1.5.2 System characteristics

2.0.1.5.2.1The transformer will be connected to overhead system which is of unearthed (i.e. without aerial earth wire) construction

2.0.1.5.2.2The primary system is having a nominal voltage of 33000 volts and 11000 volts and system highest voltage of 36000 volts and 12000 volts respectively. The primary system

30

is 3 – phase 3 – wire 50 Hz and the secondary is 433 volts three phase 4 – wire and 250 volts single phase 2 – wire.

2.0.1.5.3 DESIGN DETAILS AND INFORMATION

a) The transformer shall be oil immersed core-type and shall be designed, manufactured and

tested as per IEC 60076. Wound core transformer shall not be accepted. The transformer shall be sealed type and no drain plug shall be fitted. Oil gauge shall be

provided on all transformers and shall be of dial or floater type. The oil gauge shall be clearly readable by an operator standing at ground level a distance of 5 meters away from the transformer mounting. The oil level mark shall be clearly visible from ground level.

Transformer shall be provided with a oil temperature indicator equipped with a maximum

temperature indicator and positioned on the top cover. The temperature indicator shall have a scale ranging from 0°C to 120°C, preferably uniformly divided. A reset knob shall be provided on the Maximum indicator.

Transformer shall be provided with a pressure relief valve. The pressure relief device shall not

protrude higher than the height of the transformer bushings above the top cover. b) The complete transformer shall be “dry painted” to protect against corrosion, and the final

colour of the exterior surface shall be Dark Admiralty Grey colour No. 632 as per BS 381C. The total thickness of the paint coat shall not be less than 80 μm at any point. The inside of the tank shall be coated with oil resisting varnish or paint so that oil cannot come into contact with tank or metal at any point.

c) The transformers shall be fitted with a mounting bracket for single wood pole mounting. The mounting bolt shall be shear type to deter unauthorised removal of the transformer. d) Construction drawings (external & internal) and documentation for each size of transformer tendered shall be given, clearly detailing important dimensions, clearances, accessories, fittings and any special feature of your design. 2.0.1.6 CONSTRUCTION a) The transformer tank shall be constructed of mild steel plates fabricated by pressing or

rolling. The transformer tank shall be sealed by means of suitable gasket and be fitted with earth

terminals. At least 2 Non – standard shearing bolts to deter unauthorised opening shall be used, and shall be distributed evenly on the top cover. Where welded covers is the requirement, this shall be stated specifically in Schedule A. All bolts, nuts and washers shall be Hot Dip galvanised to BS 729.

Single phase transformers shall not have a drain plug. b) The cores shall be constructed of high quality low loss grain oriented electrical steel

laminations and designed to ensure no hot sections due to overfluxing or circulating currents across the laminations. The flux density at any point shall not exceed 1.65 tesla.

31

The cores shall be clamped effectively with metal cross-arms and be fitted with core lifting lugs.

c) The windings shall be of electrolytic copper capable of sustaining short circuit forces on the

transformer as required in clause 4.4.2.

The primary windings shall be of full coil copper wires as opposed to segmented winding and the secondary windings shall be coil or foil of copper or foil of aluminium.

d) The HV and LV windings shall be separated so as to allow for cooling and ease of repair. Insulated crepe paper shall be used for insulating the transformer tappings.

e) The high voltage winding of the single phase transformers shall have tappings at 5%

operated by an off-circuit switch (external tapping links are accepted) with marked position indicators. Switch position No. 1 shall correspond to highest voltage on the HV side.

Tapping details shall be included on the transformer name plate.

The make contacts of the tap changer shall be robust and of sufficient surface area and insulation.

f) The single phase transformer shall be wound to give a 2 - wire supply. g) Outdoor brown and glazed weatherproof bushings, provided with external stud for conductor from 7.8 mm to 18.2 mm diameter shall be mounted on the tank cover except for LV bushings which may be on the side. Clamp connections (replaceable) shall be provided where specifically requested in appendix A. The bushings shall be constructed, arranged and fitted in such a manner as to be changed without opening the transformer.

The minimum external electrical clearances and minimum creepage distance of the bushing are as indicated below, these shall be corrected in accordance with service conditions given in clause 4.1.

Nominal System Voltage between Phases 250V 11kV 33kV Minimum clearances between phase to earth mm 80 300 480 Minimum Clearances between phases mm 250 435 Minimum Creepage distance mm 60 300 900 h) The high voltage bushing shall be fitted with adjustable double-gap arcing horns set at 2 X

25mm gaps for 11kV and 2 X 55mm gaps for 33kV. Provision shall be made in form of a removable jumper, to provide for good electrical connection between the top cover and the transformer tank. The jumper shall be sufficiently rated to carry the fault currents without damage.

i) Cooling of the transformer shall be by natural circulation of oil and natural circulation of air

(ONAN). Loading will be as per IEC 60354 j) The transformer shall be filled with new mineral oil. The oil shall meet the requirements of

class 1(un-inhibited) oil specified in IEC 296.

32

k) Each transformer shall be provided with a metal name plate giving the required particulars. In addition , the name plate shall include load and no load losses for the highest, lowest and nominal tap changer positions, temperature class of insulation, connection diagram and the inscription 'PROPERTY OF KENYA POWER AND LIGHTING'.

2.0.1.7 RATINGS a) The transformer shall be capable of carrying its full normal rated current continuously under

the tropical conditions stated, and at any tappings without the temperature rise in the hottest region exceeding 55 C and 60 C in oil and winding respectively. Documents to support this shall accompany the tender.

b) The transformer shall be capable of sustaining short circuits on the low voltage side with

power maintained on the high voltage side without damage or distress for 2 seconds. Our design distribution fault level for 11 kV and 33 kV is 25 kA and 21 kA respectively.

c) The impedance voltage measured at the normal tap shall not exceed the value indicated in the

following table.

RATING (KVA) PHASE SYSTEM VOLTAGE (KV)

% IMPEDANCE

5 1 11 4.35 15 1 11 4.35 25 1 11 4.4 25 1 33 4.5

d) The guaranteed maximum sum total of the transformer losses, measured at full load

operation, unity power factor and rated voltage shall be as indicated in the table below. The loss measurements shall be adjusted to 75 degree Celsius. Further more, values of measured no load and load losses at 125%, 100%, 75%, 50% and 40% transformer loading shall be provided.

For purpose of comparison of tenders, measured total winding losses and core losses at 100%

loading adjusted to 75 degree Celsius shall be used as specified in evaluation criteria.

RATING (KVA)

PHASE SYSTEM VOLTAGE (KV)

TOTAL TRANSFORMER LOSSES (Fe + Cu) in watts

5 1 11 150 15 1 11 345 25 1 11 485 25 1 33 485

2.0.1.8 CAPITALISATION OF TRANSFORMER LOSSES

NB:- Only the allowed maximum transformers losses as per Vol 1 will be considered during tender evaluation. Transformer Capitalisation shall be carried out if the contractor fails to meet the guaranteed value as specified in Vol 1 after manufacture

33

Evaluation will be carried out to establish the capitalised values of no-load losses and load losses at nominal rating of a transformer. This cost will be added to the bid price (landed cost) of the tender. The no load and load losses provided by the manufacturer for tender evaluation shall not be subjected to further tolerance after the award.

Transformer losses shall be capitalised at the following rates

oad (winding) Losses US$ 1902 per kW for 15 years ad (core) Losses US$ 4504 per kW for 15 years

Where tenders are being compared, losses will be capitalised at the above rate and added to the bid

price according to the below formula Gep = Gbp + G($) Gep = bid evaluation price Gbp = bid price G($) = Adjustment for the cost of the operation and maintenance for 15 years And is obtained by using the following formula G($) = 1902 X full load winding losses(kW) + 4504 X no load losses(kW)

2.0.1.9 TESTS a)The manufacturer shall be responsible for performing or for having performed all the required tests specified in this specification. Tenderers shall confirm the manufacturer’s capabilities in this regard when submitting tenders. Any limitations shall be clearly specified.

Tender documents shall be accompanied by copies of Type test and Routine test reports & certificates for similar rated equipment as requested for the purpose of tender evaluation .Type Tests Reports shall be carried out by a laboratory independent from the manufacturer or with the witness of independent laboratory. Current contact information of the testing and certification authority shall be provided.

a) Routine Tests Each transformer shall have the following tests performed on it

Measurement of winding resistance Measurement of voltage ratio and check of voltage vector relationship Measurement of impedance voltage, short circuit impedance and load loss Measurement of no-load loss and current Dielectric tests Insulation oil test

34

b) Type Tests and Special Tests Type Test shall be in accordance with IEC 76. In addition the Employer may call for type tests and special tests to be carried out at the Manufacturer's Works and witnessed by the Employer or representative. Such test would be on random samples at the discretion of the Employer and failure to meet the conditions of test could result in the rejection of a complete batch of transformers. When such tests are called for they will comprise the following:

Impulse voltage test Temperature rise test Short-circuit test Acoustic sound level measurements

b)A detailed list & contact address of previous customers shall be submitted with the tender. The manufacturer shall indicate the monthly & annual production capacity and experience in the production of the type and size of transformer he is offering. List of workshop tools and equipment shall also be appended. These shall be confirmed during factory visit. 2.1 SPECIFICATION FOR THREE PHASE DISTRIBUTION TRANSFORMERS: Pole -

Mounted 3 Phase Transformers (50 – 315KVA) 2.1.1 SCOPE 2.1.1.1 This specification is for oil-immersed, air-cooled, outdoor type three phase

distribution transformers for 11kV and 33kV distribution systems operated at 50 Hz. 2.1.1.2 The specification covers transformers of the following voltage ratios and ratings. (i) 11000/433V: 50 KVA, 100 KVA, 200 KVA and 315 KVA

(ii) 33000/433V: 50 KVA, 100 KVA, 200 KVA and 315 KVA 2.1.2 SERVICE CONDITIONS

Specified in clause 1.5 and 2.2.5.1 of these specifications.

2.1.3 REFERENCES

The following documents were referred to during the preparation of this specification, in case of conflict the requirements of this specification take precedence.

IEC 60076: Power Transformers

BS 171: Power Transformers

BS 381C: Specification for colours for identification, coding and special purposes

35

IEC 296: Specification for unused mineral insulating oil for transformers and switchgear

IEC 60354: Loading guide for oil – immersed power transformers.

ESI 35 - 1: Distribution Transformers BS 729:Hot Dip Galvanized Coating on Iron and Steel Articles 2.1.4 TERMS AND DEFINITIONS For the purpose of this specification, the definitions given in IEC 60076 shall apply. 2.1.5 REQUIREMENTS 2.1.5.1 SERVICE CONDITIONS 2.1.5.1.1 Operating conditions The transformers shall be suitable for continuous operation outdoors in tropical areas at

altitudes of up to 200m above sea level, humidities of up to 90%, average ambient temperature of +30ºC with a minimum of -1ºC and a maximum of +40ºC and heavy saline conditions along the coast.

2.1.5.1.2 System characteristics 2.1.5.1.2.1 The transformer will be connected to overhead system which is of either earthed or

unearthed (i.e. with or without aerial earth wire) construction. 2.1.5.1.2.2 The primary system is having a nominal voltage of 11000 volts and 33000 volts and

system highest voltage of 12000 volts and 36000 volts respectively. The primary system is 3 – phase 3 – wire 50 Hz and the secondary is 433 volts three-phase 4 – wire.

2.1.5.2 DESIGN AND CONSTRUCTION 2.1.5.2.1 General The transformer shall be three phase, oil immersed type, air cooled, outdoor, core-type and

shall be designed, manufactured and tested as per IEC 60076. The transformer shall be either free breathing type or sealed type as specified in Appendix A

and B.

Free breathing transformers shall be provided with a conservator, and a dehydrating breather. The conservator shall be in such a position as not to obstruct the electrical connections to the transformer and oil gauge provided at one end of the conservator marked with oil levels.

36

The complete transformer shall be painted to protect against corrosion, and the final colour of the exterior surface shall be Dark Admiralty Grey colour No. 632 as per BS 381C. The total thickness of the paint coat shall not be less than 80 μm at any point. Dry Painting is also accepted. The inside of the tank shall be coated with oil resisting varnish or paint so that oil cannot come into contact with tank or metal at any point.

Each transformer shall be suitable for ‘H’ pole mounting.

Drawings and documentation for each size of transformer tendered shall be given, clearly

detailing important dimensions, clearances, accessories, fittings and any special feature of the offered design.

2.1.5.2.2 Tank

The transformer tank shall be constructed of mild steel plates fabricated by pressing or rolling. Manufacturer shall state tank thickness in Appendix A & B.

The transformer tank shall be sealed by means of suitable gasket and be fitted with earth terminals. Eight (8No.) non-standard shearing bolts to deter unauthorised opening shall be used on bolted corners and centres of sides of top cover. All bolts, nuts and washers shall be Hot Dip galvanised to BS 729.

2.1.5.2.3 Core The cores shall be constructed of high quality low loss grain oriented electrical steel

laminations (wound core transformers shall not be accepted). The design shall ensure no hot sections due to overfluxing or circulating currents across the laminations. The flux density at any point shall not exceed 1.65 Tesla.

The cores shall be clamped effectively with metal cross-arms and be fitted with core lifting lugs. The manufacturer shall demonstrate experimentally or via a previous test report, that the whole structural frame-work supporting the transformer windings and the core can definitely withstand repeated transformer short-circuits.

2.1.5.2.4 Windings The windings shall be of electrolytic copper capable of sustaining short circuit forces on the transformer as required in clause 2.2.5.2.9.

The primary windings shall be of full coil copper wires as opposed to segmented winding and the secondary windings shall be coil or foil of copper or foil of aluminium.

2.1.5.2.4.2 The HV and LV windings shall be separated so as to allow for cooling and ease of

repair. Insulating sleeves for the transformer tappings shall be in crepe paper or better.

2.1.5.2.5 Tapping The high voltage winding shall have tappings at 2 X 2.5% operated by an

off-circuit switch with marked position indicators. Tapping details shall be included on the transformer name plate.

The switch shall be located at the transformer top cover with sufficient electrical clearance and well submerged in oil. Switch position No. 1 shall

37

correspond to highest voltage on the HV side.

The make contacts of the tap changer shall be robust and of sufficient surface area. Where request is for transformers without conservators, the transformer core

and all electrical parts inside the transformer shall be sufficiently submerged in oil by no less than 120mm from the minimum oil level mark.

2.1.5.2.6 Vector Group 2.1.5.2.6.1 The three phase transformer shall be wound to IEC vector reference Dyn11 or as

specified and approved by the Employer before manufacture. 2.1.5.2.6.2 The star point of the low voltage winding shall be brought out to a neutral bushing.

2.1.5.2.7 Bushings and Clearances 2.1.5.2.7.1 Outdoor brown glazed weatherproof bushings, provided with external stud for

conductor sizes from 7.8 mm to 18.2 mm diameter shall be mounted on the tank top cover.

2.1.5.2.7.2 Bushing stud clamp connectors shall be provided where requested for in appendix A

and B. 2.1.5.2.7.3 The bushings shall be constructed, arranged and fitted in such a manner as to be

changed without opening the transformer. 2.1.5.2.7.4 The high voltage bushing shall be fitted with adjustable double-gap arcing horns set at

2 X 25mm gaps for 11kV and 2 X 55mm gaps for 33kV. For bolted transformer covers, provision shall be made in form of a removable jumper, to provide for good electrical connection between the top cover and the transformer tank. The jumper shall be sufficiently rated to carry the fault currents without damage.

2.1.5.2.7.5 The minimum external electrical clearances and minimum creepage distances of the

bushings are as indicated below, these shall be corrected in accordance with service conditions given in clause 2.2.5.1.

Nominal System Voltage between Phases 433V 11kV 33kV Minimum clearances between phase to earth

mm 80 300 480

Minimum Clearances between phases mm >100* 250 435 Minimum Creepage distance mm 60 350 950

NB: 100* mm is for the 50kVA transformer. Manufacturer to provide larger clearances for higher rated transformers.

2.1.5.2.8 Oil and Cooling 2.1.5.2.8.1 Cooling of the transformer shall be by natural circulation of oil and natural circulation

of air (ONAN). Loading will be as per IEC 60354.

38

2.1.5.2.8.2 The transformer shall be filled with new (unused) mineral oil. The oil shall be uninhibited mineral insulating oil class I as per IEC 296.

2.1.5.2.9 Fittings and Accessories 2.1.5.2.9.1 No drain valve shall be fitted unless specifically requested in Appendix A and B. 2.1.5.2.9.2 Oil gauge shall be provided on all transformers and shall be of dial or floater type.

The oil gauge shall be clearly readable by an operator standing at ground level at a distance of 5 meters away from the transformer mounting. The oil level mark shall be clearly visible from ground level. The maximum and minimum oil level marks shall fall within range of the gauge. The nominal oil level shall be at the centre of the range.

2.1.5.2.9.3 Every transformer shall be complete with an oil temperature thermometer visible from

ground level and positioned in a secure position on the transformer.

Transformer shall be provided with a pressure relief valve. The pressure relief device shall not protrude higher than the height of the transformer bushings above the top cover.

2.1.5.2.10 Rating 2.1.5.2.10.1 The transformer shall be capable of carrying its full normal rated current continuously

under the tropical conditions stated (maximum ambient temperature of 40C) and at any tappings without the temperature rise in the hottest region exceeding 55C and 60C in oil and winding respectively. Documents to support this shall accompany the tender.

2.1.5.2.10.2 The transformer shall be capable of sustaining a three-phase symmetrical short circuit

on the low voltage side with power maintained on the high voltage side without damage or distress for 2 seconds. KPLC design distribution fault level for 11 kV and 33 kV is 25 kA and 21 kA respectively.

2.1.5.2.10.3 The specification is for transformers of the following sizes:

11000/433V: 50 KVA, 100 KVA, 200 KVA and 315 KVA 33000/433V: 50 KVA, 100 KVA, 200 KVA and 315 KVA

2.1.5.2.10.4 The rated withstand voltages (internal) for the transformers shall be as follows: Highest system

voltage (r.m.s.)Rated short duration power frequency withstand voltage (r.m.s.)

Rated lightning impulse withstand voltage (peak)

11/0.433kV Transformers

12kV 38kV 75kV

33/0.433kV Transformers

36kV 95kV 170kV

2.1.5.2.11 Impedance Voltage

39

2.1.5.2.11.1 The impedance voltage measured at the principal tap shall not exceed the values indicated in the following table.

Rating KVA Impedance Voltage % 11/0.433kV Transformers 50 4.35

100 4.35 200 4.5 315 4.5

33/0.433kV Transformers 50 4.5 100 4.5 200 4.75 315 4.75

2.1.5.2.12 Losses and Capitalization

2.1.5.2.12.1 The guaranteed maximum sum total of the transformer losses, measured at full load operation, unity power factor and rated voltage shall not exceed values indicated in the table below. Measured values of the iron losses and the full load copper losses shall be adjusted to 75 degree Celsius.

Rating KVA TOTAL TRANSFORMER LOSSES e.g. (Fe + Cu) Watts

11/0.433kV Transformers 50 940 100 1840 200 3250 315 4800

33/0.433kV Transformers 50 1050 100 2000 200 3400 315 5040

In addition, values of measured no load and load losses at 125%, 100%, 75%, 50% and 25% transformer loading shall be provided together with the corresponding transformer efficiencies. However, for the purpose of comparison of tenders, measured no load losses and load losses at 100% loading shall be used.

2.1.5.2.12.2 NB:- Only maximum Transformer losses shall be considered during evaluation Evaluation will be carried out to establish the capitalised values of no-load losses and load losses at nominal rating of a transformer. This cost will be added to the bid price (landed cost) of the tender.

Transformer losses shall be capitalised at the following rates:

Full load (winding) Losses US$ 1902 per kW for 15 years

No load (core) Losses US$ 4504 per kW for 15 years Where tenders are being compared, losses will be capitalised at the above rate and added to the bid price according to the formula below.

40

Gep = Gbp + G($) Gep = Bid evaluation price

Gbp = Bid price G($) = Adjustment for the cost of the operation and maintenance for 15 years And is obtained by using the following formula

G($) = 1902 X full load winding losses(kW) + 4504 X no load losses(kW) 2.1.5.2.13 Marking and Rating Plate 2.1.5.2.13.1 Each transformer shall be provided with a rating plate of weatherproof material, fitted

in a visible position, showing the appropriate details listed in IEC 60076. The entries on the plate shall be indelibly marked (either by etching, engraving or stamping).

2.1.5.2.13.2 In addition, the name plate shall include load and no load losses for the highest,

lowest and principle tap positions, temperature class of insulation, connection diagram and the inscription 'PROPERTY OF KENYA POWER AND LIGHTING CO.' all marked indelibly as in 4.2.13.1.

2.1.6 TESTS AND FACTORY INSPECTION Type Tests Reports shall be carried out by a laboratory independent from the manufacturer or with the witness of independent laboratory. Current contact information of the testing and certification authority shall be provided.

a) Routine Tests Each transformer shall have the following tests performed on it

Measurement of winding resistance Measurement of voltage ratio and check of voltage vector relationship Measurement of impedance voltage, short circuit impedance and load loss Measurement of no-load loss and current Dielectric tests Insulation oil test

b) Type Tests and Special Tests

Type Test shall be in accordance with IEC 76. In addition the Employer may call for type tests and special tests to be carried out at the Manufacturer's Works and witnessed by the Employer or representative. Such test would be on random samples at the discretion of the Employer and failure to meet the conditions of test could result in the rejection of a complete batch of transformers. When such tests are called for they will comprise the following:

Impulse voltage test Temperature rise test Short-circuit test Acoustic sound level measurements

41

2.2 SUB STATION LOCAL TRANSFORMER - NOT COVERED IN THIS PROJECT

2.3 33KV CIRCUIT BREAKERS- NOT COVERED IN THIS PROJECT

2.4 33KV THREE POLE DISCONNECTORS

2.4.1 SCOPE

a) This specification is for 33kV, 800 Amps Isolator for isolation of substation apparatus and line isolation .

b) This specification covers the following isolators.

33 kV isolator without earth switch

33 kV isolator with earth switch

2.4.2 REFERENCES

The following documents were referred to during the preparation of this specification, and may be referred to in case of conflict, the provision of this specification shall take precedence.

Unless otherwise specified, the latest revision, edition and amendments shall apply

IEC 60129: Alternating current disconnectors (isolators) and earthing switches.

BS 729 Hot dip galvanised coating on iron and steel articles.

2.4.3 SERVICE CONDITIONS

The service condition is as stated in clause 1.5 2.4.4 CONSTRUCTION

a) The isolator shall be vertical or horizontal opening, single break or double centre break rotating post type for use on a 33kV, 50 Hz, three phase system.

b) The mechanism box shall be equipped with a 240V AC space heater controlled by a

Hygrostat with variable humidity and temperature control settings. c) The isolator shall be complete with supporting base, phase coupling details, operating

rod, unions and guides.

d) The operating mechanism shall be provided with a universal joint to allow for a reasonable degree of out-of alignment of the operating rod.

e) The supporting underbase shall be hot dip galvanised steel as per the requirement of

BS 729.

42

f) The Isolator shall be provided with a manual operating mechanism with a locking device. The Locking device shall be lockable by a padlock and the operating condition of the locking device shall be easily recognizable from the outside.

g) The underbase shall be suitable for mounting on a steel structure.

h) All the three switches shall be arranged so that the phase units are mounted

independently and then finally interconnected with coupling tubes so as to ensure simultaneous operation of all switches by drive rods and operating manual handle.

i) The operating mechanism shall be fixed at the base frame, in a weather proof, vermin

proof and dust proof housing. The degree of protection shall be class IP 54 according to IEC 144.

j) Auxilliary switches, shall be provided for electrical interlocks with a circuit breaker.

k) The isolator shall be designed such that in fully open position, it shall provide

adequate electrical isolation between the contacts on all the three switches.

l) The Isolator shall be operable by one person safely and smoothly.

m) A set of at least 5 No and 5NC potential free contacts shall be provided for indication and interloacking and shall be wired to a terminal block in the housing

n) All current carrying parts be made of electrolytic high conductivity material with

switch contacts silver plated.

o) The isolator with the earth switch shall consist of a hinged type earth switch fixed at the base frame. The earth switch shall have the same rating as the isolator.

p) Separate hand operated handle shall be provided for the Isolator and the Earth Switch.

Mechanical as well as electrical interlocking (e.g coil) shall be provided for the Isolator/Earth Switch assembly so that any switch cannot be closed when the other switch is in closed position.

q) The isolator shall be provided with a padlocking facility such that it can be locked in

either OPEN or CLOSED position.

r) The mechanism box shall be provided with locking facilities.

s) The Isolator shall have a CLOSED and OPEN mechanical indicators next to the operating handle for status indication of the isolator. Status indications shall also be provided for the earth switch.

2.4.5 RATING

The ratings of the isolator, including its operating devices and auxiliary equipment shall be as under.

Rated lightening impulse withstand voltage 170 kV Rated Power frequency withstand voltage 70kV Rated frequency 50 Hz

43

Highest system voltage at 1200m altitude 36kv Highest equipment voltage To be stated

Rated normal current Line /S/station 800 Amps Rated short time withstand current for 3 seconds 25 kA Earth switch Rated short time withstand current for 3 seconds 25KA Minimum creepage distance of Insulators 25 mm/kv

Auxiliary A.C Voltage for heater 240 V, 50 Hz 2.4.6 TESTS

(see clause 1.20) a) The isolator shall be inspected and routine tested in accordance with the requirement of IEC

60129. b) The followings are the tests:

Routine tests Assembly and operation test Measurement of resistance between main terminals 1 minute Power frequency voltage tests 1 minute power frequency voltage tests on control and auxiliary circuits Temperature rise test

Type tests (Similar rated 33kv isolators) Mechanical endurance test Impulse voltage test Short circuit circuit current test

2.5 33KV VOLTAGE TRANSFORMERS - NOT COVERED IN THIS PROJECT

.

2.6 33KV CURRENT TRANSFORMERS- NOT COVERED IN THIS PROJECT

2.7 33KV SURGE ARRESTERS

2.7.1 SCOPE This specification is for 33kV metal-oxide type surge arresters without spark- gaps for

a.c. system.

2.7.2 REFERENCES

The following documents were referred to during the preparation of this specification, and may be referred to in case of conflict, the provision of this specification shall take precedence.

Unless otherwise specified, the latest revision, edition and amendments shall apply IEC 60099: Surge Arrester.

44

Part 4: Metal-oxide surge arresters without gaps for a.c. systems. IEEE Std.: C62.22 – 1991

IEEE Guide for application of metal-oxide surge arresters for alternating – current systems.

2.7.3 SERVICE CONDITIONS

The service condition is as stated in clause 1.5

2.7.4 CONSTRUCTION a) The surge arrester shall be metal-oxide type without spark gaps and

constructed as per the requirement of IEC 99-4. b) The surge arrester shall be outdoor, explosion proof, non-linear resistor type or

gapless type, and heavy duty substation class type, designed for a rated surge current of 10 kA.

c) The metal-oxide used shall be of quality to ensure thermal stability under

service duty of the surge arrester.

d) The completed surge arrester shall be housed in a spiral type solid core Silicon Polymer .The housing shall withstand the lighting impulse voltage of the arrester.

e) The surge arrester shall be sealed (end caps) with a controlled permanent seal

to ensure no moisture absorption or deterioration of the metal-oxide element for the surge arrester.

f) The steel plates or straps shall be galvanized as per the requirement of BS 729.

2.7.5 RATING .

The rating of the voltage transformer shall be as indicated herein:- Rated voltage 27kV Continuous operating voltage 21kV Rated frequency 50Hz Highest system voltage at 1200m altitude 36kv Nominal discharge current 10kA Long duration discharge class 1 Creepage distance of insulator 25mm/kv

2.7.6 TESTS

(see clause 1.20)

45

a) The surge diverter shall be inspected and routine tested in accordance with the requirement of IEC 99-4.

b) The followings are the tests: Routine tests

a. Power frequency 1 minute voltage withstand tests on housing b. Construction check c. Impulse spark over test d. Leakage current test e. Reference voltage

Type tests a. Residual voltage test b. Pressure relief test c. Operation duty test

2.8 33 KV AND 11 KV AUTO RECLOSERS 2.81 SCOPE

This specification is for outdoor 33 and 11kV autoreclosers together with controls and ancillary equipment.

2.8.2 REFERENCES

The following documents were referred to during the preparation of this specification, and may be referred to in case of conflict, the provision of this specification shall take precedence.

Unless otherwise specified, the latest revision, edition and amendments shall apply

IEC 56: High voltage alternating current circuit breakers.

IEC 144: Degree of protection of enclosures for low voltage switchgear and control

gear.

BS 5311: Specification for a.c. circuit breakers of rated voltage above 1kV.

IEC 99-4: Metal-oxide surge arresters without gaps for a.c. systems

IEEE Std C 62.22 – 1991: IEEE Guide for application of metal-oxide surge arresters for alternating – current systems.

Auto reclosers conforming to any other current international standards, which are equal to or higher but not less rigid than the standards stipulated in the specification may be offered. When such alternative international standards are used, reference to such standards shall be quoted and English Language copies of such standards shall be submitted with the tender document, clearly highlighting the relevant clauses IEC

2.8.3 SERVICE CONDITIONS

The service condition is as stated in clause 1.5

2.8.4 CONSTRUCTION

46

a) The auto recloser shall be out-door type, designed for three phase operation and

suitable for pole mounting. b) The auto recloser shall have Oil, Air or SF6 gas for electrical insulation and

employ Vacuum in the current interruption chamber. c) The Autoreclosures shall have 3 current transformers of appropriate class and

burden inbuilt to be used for protection functions . d) Manufacturers shall ensure that suitable and sufficiently sized brackets are fitted

on both sides of the auto recloser tank for fixing of surge diverters e) SF6, Air or Oil shall be used for insulation inside the Recloser Tank. If SF6 is

used, low Gas pressure shall cause the recloser control to Lockout in its current status. I.e. it shall trip the recloser but it shall not be able to close the recloser until the gas pressure is re-established. Loss of SF6 Gas shall not result in Flash over (internal Electrical Insulation Failure) of the unit.

f) Where SF6 Gas is used for insulation inside the recloser, Leakage of SF6 gas shall

be alarmed as an event on the control Unit and will also light an LED on the control Unit.

g) A valve or appropriate accessory shall also be provided on the recloser for re-

filling the Gas, to the required pressure. The appropriate re-filling nozzles shall be supplied with the reclosers

h) The oil or SF6 gas shall be suitable for use in the auto recloser when it is operated

under the service and system conditions.

i) The auto reclosers shall be supplied complete with operating mechanism, control cubicles and all necessary brackets for mounting on a pole(s) structure. The actual number of auto reclosers and control cubicles shall be indicated by KPLC in the BQs.

2.8.5 OPERATING MECHANISM

a) The duty cycle shall be suitable for up to four Autoreclose shots on fault. b) Provision of Operation counters in the Recloser Control, as has been specified

under the Control Box, shall also be supplied. c) Provision for manual mechanical close and open operations during maintenance

shall be made. d) The Electronic Control Box shall be suitable for mounting at the auto recloser

supporting structure, and below the auto recloser in a weatherproof, dust-proof, vermin-proof housing. The necessary brackets and fittings for this purpose shall be provided. Mounting drawings shall be provided by the tenderer.

e) The degree of protection shall be class IP 54 as per the requirement of IEC 144. f) Mechanically operated indications to show the status of the auto recloser

(open/close) shall be provided. g) The auto recloser shall be provided with suitable terminals and connecting clamps

for conductors of up to 18.2 mm diameter. Suitably designed terminal covers, capable of withstanding severe tropical ultra violet radiations, shall be provided as protection against birds and animals short circuits.

h) Suppliers shall indicate the number of Recloser operations to the first maintenance as well as the number of operations between successive maintenance, i.e. the Recloser Duty Cycle.

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i) Detailed catalogues and mechanical drawings shall be supplied with the tender for the purpose of tender evaluation.

2.8.6 RATINGS

33 KV 11 KV Frequency 50Hz 50Hz Highest system voltage at 1200m altitude 36kv 12kv Nominal Current 400 Amps 400 Amps Rated short circuit current 12kA 12kA Duration of short circuit 3 Secs 3 Secs Impulse withstand voltage 170kV 75kV Power Frequency withstand voltage 70kV 28kV Minimum Creepage 25mm/kv 25mm/kv

NB: A Single bushing providing the required Creepage shall be mounted on the tank for each phase. Use of an additional boot or cable tails to be connected between the bushing and the overhead line to achieve the required creepage shall not be accepted.

2.8.7 ELECTRONIC CONTROL BOX

2.8.7.1 GENERAL The control box shall be a fully programmable microprocessor (numerical) based unit. The control box shall have the following features on its Front face. a) LCD Screen to facilitate manual programming of the control unit and for viewing data

such as Settings, events, fault records and measurands. The LCD shall preferably switch off when not in use and activated by pressing the appropriate key such as panel ON/OFF switch.

b) KEY PAD: This shall be used for programming and viewing the protection settings, measurands constants and control logic for the unit. All data stored in the unit such as settings, events, fault records and measurands shall be accessible through the keypad.

c) CONTROL KEYS: Control keys shall be provided for the following functions. (i) Enable/block earth fault protection (ii) Enable/block sensitive earth fault protection (iii) Enable/block cold load (load inrush) protection (iv) Select Remote/local control of the unit. (v) Enable/block auto reclose. (vi) Close switch and Trip Switches shall be provided for manual operation.

d) RECLOSER CONTROL HEALTHY STATUS: This shall be indicated by an

LED, on the control or on the LCD Screen. e) RECLOSER CONTROL FAILURE: This shall similarly be indicated by an LED or

on the LCD Screen. If the control fails, then all protection functions shall be blocked from operating. A potential free Auxiliary contact to indicate control box failure shall be provided and wired to the terminal block.

f) RECLOSER CONTROL SAFETY: The recloser control shall have a door on the front, which is lockable with a padlock to prevent unauthorised access to the control unit.

g) COMUNICATION PORT/SOFTWARE: The Recloser Control shall be provided with an RS232 port, and an RS 485 port at the rear for remote communication and for

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faster programming of settings and down loading of data from the unit via a laptop computer. Necessary cables for connecting a laptop to the control unit shall be supplied.

h) The necessary Software for installation into a Laptop computer to facilitate communication with the Recloser Control Unit for Programming Protection, Configuration and Control Settings and For Viewing, Downloading and Analysing Data from the Recloser Control shall be provided.

i) The software shall be supplied in suitable form for safekeeping in form of CD`s. Laptop computers (NEW) with the auto recloser software program already loaded shall be prepared for use during acceptance testing and shall be handed over to KPLC for used in the field.

j) Four (4) sets of detailed software Hard Cover Manuals describing the software installation, and application for programming the settings and configuration of the control as well as downloading and analysis of Data shall be provided.

k) Additional Four (4) copies of the Software manual in soft copy shall be supplied with the Reclosers

l) DEFAULT DISPLAY ON LCD: This shall be selectable

m) An LED shall be provided to indicate recloser lockout. Alternatively this shall be

displayed on the LCD Screen.

n) SHUNT TRIP ACCESSORY; This feature shall be included in the Control Box, to enable the Recloser to be tripped via an external Signal/Command and shall be wired to the Terminal Block of the Control Box for external connection.

o) REMOTE CLOSE ACCESSORY; This feature shall be included in the Control

Box, to enable the Recloser to be closed From a Remote Position and shall be wired to the terminal block of the control Box for external connection.

p) RECLOSER AUXILIARY CONTACTS: One set each of Potential free NO and NC

auxiliary contacts of the recloser shall be wired to the terminal Board of the control Box For external connection to monitor the status of the recloser.

q) SCADA ACCESSORY; This feature shall be required in future to monitor the status

of the Recloser and also to transmit data such as measurands, fault details, events list, etc., and also for control commands to/from the control center. The Supplier shall indicate the cost of providing features for SCADA application up to the modem interface. The supplier shall also indicate the protocol used and the communication links that can be used with this Accessory to Transfer data if SCADA application is implemented in the future. The unit will have open protocol for communication with the SCADA system.

r) OPERATION: In addition to trip/close push buttons provided on the control unit, the

control of the recloser shall be enabled in the software for control through a Laptop computer or through a remote connection.

s) EVENTS & FAULT RECORDS LISTS:The unit shall also generate a sequence of

events (time-tagged) for all operations, Auto & Manual and system status (e.g. supply failure etc.).When tripping of the unit occurs, the Protection function responsible for the trip, Phase(s) affected, Fault Current magnitudes, Fault duration, date and time (up to Hundredth of a millisecond) of the Trip, shall be displayed on the LCD Screen and

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be resettable via a reset button on the control unit. These details shall also be available in the Events List and Fault Records List and accessible by use of a Laptop Computer.

t) EVENTS LOG: Each event whether generated by manual or Automatic

operation of the recloser control, shall have the following details. (i) Serial no. (ii) Date of occurrence (DD:MM:YY) (iii) Time of occurrence, up to millisecond level and (iv) Description of the event.

u) POWER SUPPLY This shall be suitable DC Voltage provided by the inbuilt charger/Battery set within the control Box to power the control and carry out all the control Operations. The normal life of the battery shall at least be 10 years. Upon loss of charger supply, the battery shall power the electronics and provide supply for control of the recloser for at least 8 hours. Test reports shall be supplied to support this aspect. Installation instructions for the recloser, shall include instructions on connection requirements for external auxiliary 240 V AC to the Recloser control, such as Earthing requirements, Position of Local Distribution transformer relative to the Recloser, etc. Any protective device necessary to ensure safety of the Recloser Control such as surge arrester shall be included in the Tender.

Note 1: A detailed manual and drawings of the control box circuits and components shall

accompany the tender.

2.8.7.1 PROTECTION FUNCTIONS The following Protection features shall be provided in the Control Unit.

3-phase over-current and Earth fault Protection. The above shall be equipped with Inverse

time-current tripping characteristics to BS 142, IEC 60255 and ANSI (IEEE) Standards and at least 10 other non standard inverse curves. Also provision shall be made for programming of custom made curves to enhance co-ordination of the Unit with Existing Relays and Auto reclosers. Detailed information shall be submitted with the tender.

The over-current and Earth fault Protection shall also be equipped with 2-stage high set (instantaneous) elements.

Sensitive Earth fault shall be provided with definite time characteristic. Auto reclose of up to four shots shall be provided. Each Autoreclose shot, shall be

initiated by any of the above Protection functions which is selected to do so. The tripping curves for each stage of the auto reclose sequence shall be programmed separately for over-current and Earth fault Protection.

The dead time for each Auto reclose shot shall be separately programmable The Following Functions/Features shall be provided on the control unit:

Recloser Trip & Close switch Recloser ON/OFF Status Indication Auto Reclose - Block ON/OFF switch Earth Fault- Block ON/ OFF switch Sensitive Earth Fault- Block ON/OFF switch

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The battery for the control box shall be rechargeable. The charger circuit shall be capable of accepting input from the recloser Tank on the source side and from an external 240V AC Auxiliary Supply.

The following Protection Functions/features shall also be included: - Cold load pick up protection Inrush restraint. Broken conductor Protection Live load blocking (where the Load side of the recloser is energised prior to closing the

recloser). The Following Functions/Features shall be included in the Software:

Number of trips to lock out selectable from menu. Operations counters for each Phase and for Earth Fault and Sensitive Earth Fault. Fault Records logging: date, time, faulted phase, fault current and fault duration

Any control box shall work with any Recloser Tank, without any limitation and achieve the declared functionality. Cases where A given control Box is calibrated and programmed to work with a specific Recloser Tank to achieve the declared performance shall not be accepted.

2.8.7.2 ENERGY AND POWER MEASUREMENT FUNTIONS

The Energy metering shall be external to the A/R`s thus not required

2.8.8 TESTS (Refer to clause 1.20)

Type and routine tests shall be carried out as per the requirement of IEC60056.

b) Routine tests: Construction test. Operation test. 1 minute Power frequency voltage withstand Insulation test . 1 minute power frequency Voltage tests on controls and auxiliary

circuits. Measurement of resistance of the main circuit. Autoreclose cycle test Temperature rise test.

c) Type tests (Similar rated 33 KV and 11kv Autorecloser)

Mechanical endurance test. Impulse voltage test. Interrupting Capacity test.

2.8.9 SPARES

The following Spares shall be supplied as part of the Re-closer :- a) 1 Unit Control Box Battery; b) Connection Cable from Recloser to the Control Box;

c) Other consumable spares to guarantee operation for the next 5 Years.

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The quantities to be supplied shall be stated in the tender document.

Note: The necessary mounting, operation and maintenance tools and equipment shall be included in the offer at no extra cost to KPLC. A list of such tools & equipment shall be provided in the tender

2.9 11 KV METAL CLAD INDOOR SWITCHGEAR – NOT COVERED IN THIS PROJECT

2.10 PROTECTION RELAYS, CONTROLS AND MEASURING DEVICES PANELS REQUIREMENTS-NOT COVERED IN THIS PROJECT

2.11 ELECTRICAL PROTECTION RELAYS- NOT COVERED IN THIS

PROJECT

2.12 A) ENERGY TARIFF METERS - NOT COVERED IN THIS PROJECT 2.12 B) TEST EQUIPMENTS - NOT COVERED

2.13 BATTERIES AND CHARGER 110 VDC-NOT COVERED IN THIS PROJECT

2.14 SUBSTATION LOW VOLTAGE PANELS ( AC AND DC ) -NOT COVERED IN THIS PROJECT

2.15 11KV ISOLATORS-AIR BREAK SWITCHES

2.15.1 SCOPE

i) This specification is for 11kV Isolators for use on line disconnection and sectionalising purposes.

ii) This specification is for horizontal mounting only.

2.15.2 REFERENCES

The following documents were referred to during the preparation of this specification, and may be referred to, in case of conflict; the provision of this specification shall take precedence. Unless otherwise specified, the latest revision, edition and amendments shall apply (1) IEC 129: Alternating Current Disconnectors (isolators) and Earthing Switches.

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(2) BS 729: Hot - dip Galvanised Coating on Iron and Steel Articles. (3) IEC 60265: High Voltage Switches (4) IEC 60694: Common Specifications for High Voltage Switchgear and Control gear.

2.15.3 SERVICE CONDITIONS

The service condition is as stated in clause 1.5

2.15.4 CONSTRUTION

i) The isolators shall be of the vertical opening, rocking type designed for three phase operation, manually operated by means of push - pull reciprocating mechanism for use on an 11kV, 50 Hz, three phase system.

ii) Each switch pole shall incorporate three porcelain insulators mounted on hot dipped galvanised steel under base and suitable for vertical and horizontal mounting.

The centre insulator shall be moveable to effect contact operation. Galvanising shall be a s per the requirement of BS 729. iii) All the three switch poles shall be arranged so that the phase units are mounted

independently and then finally interconnected with coupling tubes so as to ensure simultaneous operation of all switches by drive rods and an operating handle for manual operation.

Where a drive rod is used, it shall be fitted with a stay insulator of not less than 0.5m long in the middle.

iv) The isolator shall be designed such that in fully open position, it shall provide adequate electrical isolation between the contacts on all the three switches.

v) All current carrying parts be made of electrolytic high conductivity copper with switch contacts hard drawn and silver plated.

vi) Provision shall be made for padlocking in both CLOSED and OPEN positions. vii) The isolator shall be fitted with clamp connectors for ACSR conductor of up to 18.2mm

diameter. viii) The isolator shall be fitted with spring arc horns to enable the isolator to interrupt loads

of up to 20 Amps.

2.15.5 RATING The ratings of the isolator shall be as under.

Highest system voltage 12kV

Rated lighting impulse withstand voltage 75kV

Power frequency withstand wet and dry 28kv

Rated frequency 50Hz

Rated normal current 600 Amps

Rated short time withstand current for 3 seconds 25kA

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Minimum creepage distance of insulators 25mm/kv

2.15.6 TESTS (see clause 1.20)

a) The isolator shall be inspected and routine tested in accordance with the requirement of IEC 60129. b) The followings are the tests:

Routine tests Assembly and operation test Measurement of resistance between main terminals 1 minute Power frequency voltage tests 1 minute power frequency voltage tests on control and auxiliary circuits Temperature rise test

Type tests (Similar rated 11kv ) Mechanical endurance test Impulse voltage test Short circuit current test

2.15.7 33 KV AND 11KV SINGLE PHASE ISOLATING LINK

TYPE

Outdoor, hook – stick operated type. All other accessories necessary for full installation, operation and maintenance shall be provided for the isolating links.

2.16 11KV SURGE ARRESTERS

2.16.1 SCOPE

This specification covers the requirements for the design, manufacturing and test of 11kV metal-oxide type surge arresters without spark gaps for a.c. system.

2.16.2 REFERENCES

The following documents were referred to during the preparation of this specification. In case of conflict, the provision of this specification shall take precedence.

Unless otherwise specified, the latest revision, edition and amendments shall apply. IEC 99: Surge Arrester. Part 4: Metal-oxide surge arresters without gaps for a.c. systems. IEEE Std.: C62.22 – 1991

IEEE Guide for application of metal-oxide surge arresters for alternating – current systems.

2.16.3 SERVICE CONDITIONS

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The service condition is as stated in clause 1.5

2.16.4 CONSTRUCTION

i) The surge arrester shall be metal-oxide type without spark gaps and constructed as per the

requirement of IEC 99-4. ii) The metal-oxide used shall be of quality to ensure thermal stability under service duty of

the surge arrester. iii) The completed surge arrester shall be housed in a spiral type solid core with silicon

polymer housing. The housing shall withstand the lighting impulse voltage of the arrester.

iv) The surge arrester shall be sealed (end caps) with a controlled permanent seal to ensure no moisture absorption or deterioration of the metal-oxide element for the surge arrester.

v) The surge arrester shall be supplied with fixing accessories and fitted with suitable connectors for ACSR conductor of diameter from 7.0mm to 18.2mm.

The steel plates or straps shall be galvanized as per the requirement of BS 729. The mounting brackets shall be suitable for both horizontal and vertical mounting on a

steel channel.

2.16.5 RATINGS The rating of the surge arrester shall be indicated herein:-

Rated Voltage 9kV Maximum continuous voltage rating 7kv Nominal discharge current 10kA Long duration discharge class 1 Creepage distance of housing 25mm/kV BIL 28/75kv Rated frequency 50Hz

2.16.6 TESTS (see clause 1.20)

a)The surge diverter shall be inspected and routine tested in accordance with the requirement of IEC 99-4. b)The followings are the tests:

Routine tests a) Power frequency 1 minute voltage withstand tests on housing b)Construction check c)Impulse spark over test d)Leakage current test e)Reference voltage

Type tests f)Residual voltage test

a) Pressure relief test h)Operation duty test

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All other accessories necessary for full installation of the Surge Arrester, shall be provided.

2.17 LOW VOLTAGE CABLES

a) 600V Cables

Low-tension circuit from station local transformer to AC distribution panel: 600V cable shall be copper conductor, polyvinyl chloride insulated PVC sheathed, 600V 300sqmm x 4-cores. Low-tension motor circuit from AC distribution panel to each motor: The sectional area of the 600V cables shall be ample for each motor capacity and shall be decided by the Contractor take into account of the voltage drop for starting current.

b) Control Cables

Control cables shall be copper conductor, of jacket type, 600V, polyvinyl chloride insulated PVC sheathed, single or multi-cores copper. The sectional area of core shall not be less than 2.5sq mm. The sectional area of core for current transformer circuit control cables shall not be less than 4 sq mm. The control cables must be armoured.

c) Insulated Wire

600 V PVC insulated wire shall be flex stranded copper conductors and used for heaters for indoor wirings.

d) Cables Drawn into Ducts Cables Drawn into Ducts

Unless otherwise specified, the Contractor shall provide ducts and pipes. Immediately before pulling the cables, the Contractor is to remove any loose material from the ducts and prove them by drawing through a mandrel of slightly less diameter than the duct. The ducts shall be water and vermin proof sealed and for indoor installations fireproof.

e) Cables Installed in Concrete Trenches and Road crossings. In substations and road crossings, concrete trenches, drilling and cable ducts shall be

provided and installed by the Contractor. These trenches shall not be filled with sand. All cable duct entries to buildings, whether or not for cables, shall be against entry of water, oil and vermin with a suitable filling materials’ supplied and installed by the Contractor on the approval of the Employer.

All cable routes in concrete trenches shall be suitable supported by means of cleats or

racks and raised from the trench floor by means of suitable spacers. All cables shall be run in a neat and orderly manner and the crossing of cables within the trench shall be avoided as far as possible.

The Contractor shall be responsible for removing and replacing the trench covers free

of charge during the execution of his work as directed by the Engineer. f) Bus Conductors Following conductors shall be provided as outdoor bus and jumper conductors:

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For 33kV bus and jumper (i) Pipe bus: Copper pipe – 50mm (diameter) x 5mm (thickness) (ii) Overhead bus: AAC.150 sq.mm

g) Galvanized Steel Wires Galvanized steel wires of 55 sq.mm (7/3.2 mm) shall be used for overhead ground

wires, of which ultimate tensile strength shall be more than 90kg/sq.mm. h) Fittings

Suitable PG clamps terminals and spacers for conductors, suitable terminals for the equipment to conductor, and suitable clamps for galvanized steel wire shall be supplied and installed. PG clamps shall be free from electrolytic corrosion and designed for bi-materials against the connection between aluminium and copper. The following tests, as applicable, shall be carried out at the Contractor’s plant: (a) Construction test (b) Tensile strength test (c) Elongation test (d) Resistance test (e) Insulation resistance test (f) Withstand voltage test (g) Characteristics

2.18 INSULATORS, FITTINGS AND SUBSTATION STRUCTURES

2.18.1 Disc Insulator Units Each suspension and strain insulator string shall be of 3 units for 33kV circuits and 2 units for 11 kV circuits without arcing horn. The insulator unit shall be standard 254 mm porcelain, or Glass disc type with ball and socket, and have a spacing of 146mm between discs, complying with IEC publication 305-1974. The connection between units shall be such as allow sufficient flexibility for freedom of movement, and to prevent the possibility of becoming separated accidentally either during or after the erection. The interlocking sockets shall be designed to allow easy passage of the ball into the socket and retaining or locking devices required to keep in the socket under all service conditions. The dimensions of socket and pin shall be in accordance with IEC. Recommendation 120, 16mm socket and pin. The insulator units shall be brown glazed or glass disc.

Each insulator unit shall have the following characteristics:

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Power frequency, dry 70kV Power frequency, wet 40kV Impulse voltage 110kV Puncture voltage 110kV Minimum breaking load 70 kN

2.18.2 Station Post Insulators Station post insulators shall be provided for supporting the connecting lead wires of switchgear equipment to bus. The insulator shall be of brown coloured porcelain rated as follows:

AC withstand voltage (wet, 1 min.) 70kV Impulse withstand voltage 170kV

The station post insulator shall comply with IEC.273-1968, IEC 720. 2.18.3 Fittings

All fittings shall be malleable iron hot dip galvanized.

Suspension and tension clamps shall be as light as possible and of approved types. All clamps shall be designed to avoid any possibility of deforming the stranded conductors and separating the individual strands. Tension clamps shall be bolted type, and shall not permit slipping off or damage to conductors or any part thereof. Suspension clamps shall be free to pivot in the vertical plane containing the conductor. Clamps shall not exhibit excessive heating by magnetized or other reasons. U-bolts, ball hooks, socket-eyes and other necessary fittings required for the above insulators and clamps shall be provided. The following tests shall be carried out before shipment and the results sent to the employer :-

(a) With stand and flashover voltage (b) Mechanical strength (c) Dimensions of insulators and fittings (d) Galvanizing

2.18.4 STEEL STRUCTURES - NIL

2.18.5 EARTHING MATERIALS As per clause 1.8 and clause 3.18

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2.18.6 OTHER MATERIALS All other miscellaneous materials, such as conduct pipes, steel plates, fabricated cable

ducts, cables supporting brackets sand/or cable racks, pipe hangs, angle steels, channels steels, bolts and nuts and other items, required for putting into service the works to be covered under this Contract, shall be supplied and installed by the Contractor as required. These materials shall comply with the highest grade specified in the relevant standards.

Coloured phase mark plates and bus identification marks shall be fitted on each beam of steel structures of incoming feeders, outgoing feeders, main buses and transformers buses.

Colour of phase marks shall be red, yellow and blue. 2.18.7 LIGHTING SYSTEM - NIL 2.18.8 SWITCHYARD LIGHTNING PROTECTION. NOT APPLICABLE IN THIS PROJECT

2.18.9 MARSHALLING BOXES- NOT APPLICABLE IN THIS PROJECT

2.19 ELECTRICAL POWER CABLES AND FITTINGS(11KV)- NOT COVERED IN THIS PROJECT

2.20 CIVIL ENGINEERING AND BUILDING WORKS - General

2.21 TESTS AT SITE

During the construction and after the installation of each item of equipment under the Section 2 tests shall be performed, as specified herein, to establish the accuracy of the assembly and to prove the adequacy of the materials and the workmanship. All tests and tests procedures shall be approved by the Employer.

The Contractor shall perform the tests of each subsection, for all items where applicable, to insure that the equipment has been correctly installed, all necessary adjustments and settings made, and that the item is in sound condition to run under load and as designed.

(A) Inspection during erection of equipment

(a) Appearance check of all equipment (b) Oil tightness check and gas leakage tests (c) Measurement of the resistance of the main circuits

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(d) All electrical tests as per the manufacturers testing protocols and the Employers recommendations for the Equipment.

(B) Test after the installation of equipment

(i) Distribution Transformers a) Voltage measurement

b) Insulation measurement c) Arching gap setting

(ii) 33kV & 11kv Auto reclosers a. A/Rs

(a) Closing and opening operation test (b) Trip-free operation test (c) Manual operation test (d) Remote operation test (e) Minimum coil operation coil resistance and pickup currents (f) Measurement of insulation resistance (g) Protection , measurement and indication tests

b. Disconnecting switches (a) Operation test (manual and remote) (b) Check of interlock mechanism and indications (c) Measurement of insulation resistance (d) Contact resistance

c. Lightening arresters (a) Measurement of insulation resistance

d Miscellaneous materials a. Outdoor bus

(a) Measurement of insulation resistance b. Power cables

(a) High voltage test (b) Insulation resistance measurement

c. Control cables (a) Insulation resistance measurement

(e) Appearance check of all equipment 2.22 RADIO EQUIPMENT - NOT COVERED IN THIS PROJECT

2.23 SPECIFICATION FOR 11KV NEUTRAL CURRENT TRANSFORMERS-NOT COVERED IN THIS PROJECT 2.24 SPECIFICATION FOR 11KV CURRENT TRANSFORMERS FOR FEEDERS- NOT COVERED IN THIS PROJECT 3. TECHNICAL SPECIFICATIONS FOR 33 , 11 & 0.433 KV OVERHEAD LINES 3.1 GENERAL REQUIREMENTS

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Overhead lines shall be of earthed Aerial wire ( Where required ) construction on wooden supports and using steel cross arms, porcelain pin insulators, composite insulators and glass discs. 3 glass discs are used for the tension string for 33kV. Every line pole shall have a pole cup, Bolts, Nuts, washers, pole number and Hatari/danger plate. All steel work is bonded and earthed. The following fittings are used as required during construction and as per the drawings

3.1.a Inter pole fittings.

Pin insulators mounted horizontally on a steel cross arm attached to the pole. See drawing. Where there are angles of deviation upto 5º, double cross arms are used. Tie straps used to hold the cross arm level and to give support. See drawings

3.1.b Vertical Flying Angle fittings Where angles of deviations are upto 60deg, this type of construction may be used. In this construction the conductors are erected vertically and attached to the pole via suspension clamps at the end of a string of glass insulators. The conductor is continuous. See drawings

3.1.c Vertical Section Pole Fittings Where deviations of upto 90 degrees are required, the above fitting is used. The conductor is broken and a non tension clamp connection is used to keep the circuit continuous. The phase conductors are arranged vertically and 2 sets of glass insulator strings for each phase are used. See drawings

3.1.d Horizontal Section Pole Fittings In this arrangement the phase conductors are arranged horizontally and is broken and attached to the pole via glass insulator strings. Two cross arms are used and two poles may be used (one each midway between the phases) depending on the adjacent span lengths. See drawings

3.1.e Terminal Pole Fittings Conductors are arranged horizontally and terminated in tension via string of glass insulators onto a steel cross arm. See drawing No.

3.1.f Tee –off Pole Fittings These are fittings used to connect to an existing line and are terminated in tension. The arrangement may be horizontal or vertical but in both cases a string of glass insulators is used with a steel cross arm being required additionally for the horizontal arrangement. See drawings

3.1.1 FACTOR OF SAFETY

The minimum factor of safety at assumed maximum simultaneous working loading shall be as follows:-

i) Line conductors based on ultimate strength Max tension -3.0 Everyday stress -5.0

ii) Insulator and fittings, based upon electro-mechanical test and minimum failing load Insulators and insulator fittings -2.5 Dead-end clamps and conductor fittings -2.5

iii) Steel structures, bolts and other steel pole members based on elastic limit of tension members and on crippling loads of compression members:- Steel Structures -2.5 (Including steel cross arm) Bolts, nuts and washers -2.5

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iv) Supports, stays and cross arms subjected to the longitudinal transverse and vertical loads resulting in the lading conditions stated above:- Wood supports and cross arms -3.5 Concrete structures -2.5 Steel supports and cross arms 2.5 Stay assembly and fittings -2.5 Foundation – Concrete -2.5

3.1.2 WORKING CONDITIONS

The maximum assumed working conditions shall be as follows:- i) Minimum temperature of line 5oC ii) Ambient temperature of line conductor 35oC iii) Maximum temperature of line conductors 65oC iv) Wind pressure on the whole projected area of conductors 400N/m2 v) Wind pressure on projected are of insulator 400N/m2 vi) Wind pressure on projected are of support 400N/m2

3.1.3 CLEARANCES AND SPANS

1) Medium overhead lines minimum clearances at operating temperatures:- i) Lines not exceeding 11kV 6m ii) Lines not exceeding 33kV 7m

2) Additional Clearances

11kV line conductor to any part of the building 2.7m

3) Special Clearances a) Railway crossing clearances

i) All types of line including guard nets – 8.1m ii) The minimum clearance of any pole or structure from the center of a tract shall be

the height of the pole above ground plus 2.1m iii) Where the tract is in a cutting, no such pole shall be closer to the edge of the

cutting than a distance equal to the height of the pole. b) Kenya Posts and Telecommunications Installation Clearances

i) Guard net – 1.3m Up to 33kV conductors using cradle guard – 1.8m Angles of crossing Medium voltage, not less than 60o.

3.2 OVER HEAD LINES CONSTRUCTION MATERIALS SPECIFICATIONS Each of the several parts of the line shall be of such construction and design as to give long and continuous service with high economy and low maintenance costs. All material used and equipment provided under this contract shall be new and of the best quality and workmanship and shall be of the highest class throughout with the designs and dimensions of all parts such that stresses which they are subjected shall not render them liable to distortion or damage under most severe conditions encountered in service. Repair of any defective parts shall not be permitted without the sanction in writing of the Employer. The detailed has been carried out in manner to facilitate inspection, repairs and simplicity of operations and maintenance. All shall ensure satisfactory operations under the atmospheric conditions prevailing in the area where the lines are to be built, irrespective of season and under such variations of load and voltage as may occur under working conditions of the

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system. Line supports, conductors, insulators and fittings shall be such as to minimize the risk of damage due to deterioration, or damage in service of any part of the line. Construction to incorporate any reasonable precaution and provision for the safety of those concerned in the maintenance of the Contract Works and all associated woks supplied and executed under other contracts. All corresponding parts shall be made to gauge, shall be inter-changeable wherever possible throughout the Contract Works and are to be such as will facilitate the fitting of replacement.

3.3 SPECIFICATIONS FOR OVERHEAD ALUMINIUM CONDUCTORS STEEL- REINFORCED. 3.3.1. SCOPE

a) This specification is for Aluminium conductors Steel Reinforced for medium voltage overhead power distribution lines.

b) This specification covers the following conductor sizes.

25 Sq. mm Aluminium Conductor Steel Reinforced, bare 25 Sq. mm Aluminium Conductor Steel Reinforced, Polyvinyl Chloride (PVC) covered.

75 Sq. mm Aluminium Conductor Steel Reinforced, bare

150 Sq. mm Aluminium Conductor Steel Reinforced, bare 3.3.2. REFERENCES

The following documents were referred to during the preparation of this specification, and may be referred to. In case of conflict, the provision of this specification shall take precedence.

Unless otherwise specified, the latest revision, edition and amendments shall apply.

BS 215: Aluminium conductors and Aluminium conductors steel - reinforced for overhead

power transmission Part2 Aluminium conductors, steel - reinforced

BS 2627: Wrought Aluminium for Electrical purposes

BS 4565: Galvanised steel wire for Aluminium conductor steel reinforced.

BS 6746: PVC Insulation and sheath of electric cables

BS 6485: PVC covered conductors for overhead power lines.

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IEC 209: Aluminium conductors, steel - reinforced 3.3.3. TERMS AND DEFINITIONS

For the purpose of this specification, the definitions in the reference standards shall apply.

3.3.4. SERVICE CONDITIONS

See clause 1.5 3.3.5. MATERIALS 3.3.5.1 Aluminium wires used in the construction of the conductor shall be GIE grade H9 as

specified in BS 2627: Wrought Aluminium for Electrical purposes. 3.3.5.2 The galvanised steel wires used in the construction of the conductor shall be as per BS 4565:

Galvanised steel wire for Aluminium Conductors - Steel Reinforced. 3.3.6. CONSTRUCTION 3.3.6.1 The conductor shall be manufactured as per BS 215 part 2:1970. 3.3.6.2 The conductor shall be concentrically stranded, with successive layers in opposite lay, but

such that the outer layer shall be in the right hand spiral (Z) Variation in diameter shall not exceed ±1% of aluminium wires, and ±2% of steel wires.

3.3.6.3 The wires in each layer shall be evenly and closely stranded. 3.3.6.4 For the bare conductor, An approved grease shall be applied at least to the centre and outer

wires as protection against corrosion. 3.3.6.5 For the covered conductor, the insulation shall be black polyvinyl chloride (PVC) compound

type T II as per BS 6746;1976 and shall be applied by extrusion. 3.3.6.6 The insulation shall have a thickness of not less than 1.6mm and the covered conductor shall

comply with the requirement of BS 6485: 1971. 3.3.7. STANDARD SIZES The Standard Sizes for the aluminium and steel wires used in the construction of the conductors and

the conductors sizes shall be as follows:-

CONDUCTOR Bare (Golpher)

PVC Covered

Bare (Racoon)

PVC Covered

Bare (Wolf)

Nominal Area of Aluminium (mm²)

25 25 75 75 150

Approximate overall diameter (mm).

7.08 7.08 12.3 12.3 18.13

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Overall diameter of covered conductors.

- 10.7 16.3

Stranding No/mm Al. 6/2.36 6/2.36 6/4.09 6/4.09 30/2.59 St. 1/2.36 1/2.6 1/4.09 1/4.09 7/2.59 Calculated maximum d.c. resistance at 20°C ( /Km)

1.093 1.093 0.3633 0.3633 0.1828

Calculated minimum breaking load (k.N)

9.61 9.61 27.4 27.4 69.2

Approximate mass of conductor (Kg/Km)

106 190 318 460 726

3.3.8. TESTS 3.3.8.1 The conductor shall be inspected and routine tested in accordance with the requirements of

BS 215 Part 2. 3.3.8.2 The following tests shall be done at manufacturers works.

ALUMINIUM WIRES

Tensile test Wrapping test Resistivity test

STEEL WIRES

Determination of stress at 1% elongation Tensile test Wrapping test Galvanising test

t The following tests shall be carried out on completed conductor

Lay ratio of each layer Tensile strength Measurement of weight Resistance test

3.3.9. CONDUCTOR ACCESSORIES

i) Tension joints shall be applied at appropriate locations ii) Torsion sleeve joints shall be used for mid-span joint. This should be able is

designed to withstand full tension of the line.

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iii) Non tension joints shall be applied at appropriate locations iv) Parallel Groove (PG) CLAMP shall be applied to joint conductors where there is

no mechanical load.

3.3.10. CONDUCTOR STRINGING Conductor running out shall be done with all necessary care to avoid kinking, nicking

of various strands and chuffing of the conductor between the drum and the snatch blocks.

3.4 a) SPECIFICATIONS OF ALL ALUMINIUM CONDUCTORS (SOFT DRAWN). 3.4.1 SCOPE 3.3.1.1bThis specification is for All Aluminium conductors (Soft drawn) intended for use on low voltage overhead power distribution lines. 3.3.1.2bThis specification covers the following conductor sizes.

50 Sq. mm All Aluminium stranded conductor, polyvinyl chloride (PVC) covered.

100 Sq. mm All Aluminium stranded conductor, Polyvinyl Chloride (PVC) covered. 3.4.2 REFERENCES

The following documents were referred to during the preparation of this specification, and may be referred to. In case of conflict, the provision of this specification shall take precedence.

Unless otherwise specified, the latest revision, edition and amendments shall apply.

BS 215: Aluminium conductors and Aluminium conductors steel - reinforced for overhead

power transmission Part1 Aluminium stranded conductors.

BS 2627: Wrought Aluminium for Electrical purposes

BS 6746: PVC Insulation and sheath of electric cables

BS 6485: PVC covered conductors for overhead power lines. IEC 207: Aluminium stranded conductors.

3.4.3TERMS AND DEFINITIONS

For the purpose of this specification, the definitions in the reference standards shall apply.

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3.4.4 SERVICE CONDITIONS As stated in clause 1.5 3.4..5 MATERIALS Aluminium wires used in the construction of the conductor shall be 1350 grade 0 as specified in BS 2627: Wrought Aluminium for Electrical purposes. 3.4.6 CONSTRUCTION 3.3.6.1bThe conductor shall be manufactured as per BS 215 part 1:1970. 3.3.6.2bThe conductor shall be concentrically stranded, with successive layers in opposite lay, but such that the outer layer shall be in the right hand spiral (Z) Variation in diameter shall not exceed ±1% of aluminium wires.

The wires in each layer shall be evenly and closely stranded. 3.3.6.3bThe conductor shall have an inner insulation of red PVC and oversheath of black PVC compound type T II according to BS 6746 (1976) and shall be applied by extrusion. 3.3.6.4bThe insulation shall have a thickness of not less than 0.5mm with oversheath of not less than 0.8mm. 3.4.7. STANDARD SIZES The Standard Sizes for the aluminium wires used in the construction of the conductors and the

conductors sizes shall be as follows:-

CONDUCTOR units 50 sq. mm 100 sq. mm

Nominal Area of Aluminium mm.² 50 100

Approximate overall diameter mm. 9.30 13.17

Overall diameter of covered conductors. mm 11.7 16.00

Stranding No/mm 7/3.10 7/4.39 Calculated maximum d.c. resistance at 20°C /Km 0.5419 0.2702

3.4.8 TESTS 3.3.8.1bThe conductor shall be inspected and routine tested in accordance with the requirements of BS 215 Part 1. 3.3.8.2bThe following tests shall be done at manufacturers works.

Tensile test

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Wrapping test Resistivity test Lay ratio of each layer Tensile strength Measurement of weight Resistance test

3.4 b) ALL ALUMINIUM CONDUCTORS. 3.4.1b SCOPE

This specification covers the design, manufacture testing and supply of All Aluminium conductors for use on low voltage overhead power distribution lines. This specification covers the following conductor sizes. 50 Sq. mm All Aluminium Conductor, bare.

50 Sq. mm All Aluminium Conductor, Polyvinyl Chloride (PVC) covered. 100 Sq. mm. All Aluminium Conductor, bare 100 Sq. mm All Aluminium Conductor, Polyvinyl chloride (PVC) covered.

3.4.2b REFERENCES

The equipment shall comply with the latest edition and amendments of the Standards listed herein. BS 215: Aluminium conductors and Aluminium conductors steel - reinforced for overhead power transmission

Part1 Aluminium Stranded conductors. BS 2627: Wrought Aluminium for Electrical purposes BS 6746: PVC Insulation and sheath of electric cables BS 6485: PVC covered conductors for overhead power lines. IEC 207: Aluminium Stranded conductors.

3.4.3b MATERIALS

Aluminium wires used in the construction of the conductor shall be GIE grade H9 as specified in BS 2627: Wrought Aluminium for Electrical purposes.

3.4.4b CONSTRUCTION

(a) The conductor shall be manufactured as per BS 215 part 1:1970. (b) The conductor shall be concentrically stranded, with successive layers in opposite lay, but

such that the outer layer shall be in the right hand spiral (Z) Variation in diameter shall not exceed ±1% of Aluminium wires.

The wires in each layer shall be evenly and closely stranded.

(c) For the bare conductor, An approved grease shall be applied at least to the centre and outer wires as protection against corrosion.

(d) For the covered conductor, the insulation shall be black polyvinyl chloride (PVC) compound type T II as per BS 6746;1976 and shall be applied by extrusion.

The insulation shall have a thickness of not less than 0.8mm and the covered conductor shall comply with the requirement of BS 6485: 1971.

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3.4.5b STANDARD SIZES

The Standard Sizes for the Aluminium and steel wires used in the construction of the conductors and the conductors sizes shall be as follows: - CONDUCTOR Units Bare PVC

Covered) Bare

PVC Covered

Nominal Area of Aluminium

mm² 50 50 100 100

Approximate overall diameter

mm. 9.30 9.30 13.17 13.17

Overall diameter of covered conductors.

mm 11.7 16.0

Stranding No/mm Al. No./mm 7/3.10 7/3.10 7/4.39 7/4.39 Calculated maximum d.c. resistance at 20°C

� /Km

0.5419

0.5419

0.2702

0.2702

Calculated minimum breaking load

kN 8028 8.28 16.00 16.00

Approximate mass of conductor

Kg/Km 145 200 290 360

3.4.6 TESTS

(a) The conductor shall be inspected and routine tested in accordance with the requirements of BS 215 Part 1.

(b) The following tests shall be done at manufacturers works.

ALUMINIUM WIRES Tensile test Wrapping test Resistivity test The following tests shall be carried out on completed conductor Lay ratio of each layer Tensile strength Measurement of weight

Resistance test 3.4.7 PACKING

(a) The complete conductor shall be rolled on wooden drums such as to prevent damage during transportation.

The wooden drums shall be made from treated timber resistant to termite attack.

(b) The following description shall be marked on one flange of the reel

Direction of rotation of the reel

Type of conductor and size

Length

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Gross weight and net weight

Manufacturer’s name

Year of manufacture

3.5 SPECIFICATIONS OF PVC COVERED COPPER CONDUCTORS. 3.5.1. SCOPE

This specification is for copper conductors for earthing power distribution and transmission system.

This specification covers the following conductor sizes.

50 Sq. mm stranded copper conductor, PVC covered.

70 Sq. mm stranded copper conductor, PVC covered .

100 Sq. mm stranded copper conductor, PVC covered.

3.5.2 REFERENCES

The following documents were referred to during the preparation of this specification, and may be referred to. In case of conflict, the provision of this specification shall take precedence.

Unless otherwise specified, the latest revision, edition and amendments shall apply.

BS 125: Hard – drawn copper and copper – cadmium conductors for overhead power

transmission purposes.

BS 6485: PVC – covered conductors for overhead power lines.

BS 6746: PVC insulation and sheath of electric cables.

BS 4109: Specification for copper for electrical purposes. Wire for general electrical purposes and for insulated cables and flexible cords.

3.5.3 TERMS AND DEFINITIONS

For the purpose of this specification, the definitions in the reference standards shall apply. 3.5.4 SERVICE CONDITIONS See clause 1.5 3.5.5. MATERIALS

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3.5.5.1 Copper wires used shall be high conductivity hard drawn copper wires. The wires shall be

clean, smooth and free from harmful defects. 3.5.5.2 The conductor cover shall be black polyvinyl chloride (PVC) compound Type TII according

to BS 6746 and shall be applied by extrusion. 3.5.5.3 The insulation shall have a thickness of not less than 0.8 mm and the covered conductor shall

comply with the requirement of BS 6485. 3.5.6 CONSTRUCTION 3.5.6.1 The conductor shall be manufactured as per BS 6485. 3.5.6.2 The conductor shall be concentrically stranded, with successive layers in opposite direction

of lay, but such that the outer layer shall be in the right hand spiral. The wires in each layer shall be evenly and closely stranded.

3.5.7 STANDARD SIZES

The Standard Sizes for copper conductors shall be as follows:-

CONDUCTOR Nominal Area of Copper (mm²) 50 70 100 Approximate overall diameter of uncovered conductor(mm).

9.00 10.65 12.9

Approximate overall diameter of covered Conductor (mm).

11.9 13.5 15.7

Stranding No/mm 7/3.00 7/3.55 7/4.30 Calculated maximum d.c. resistance at 20°C ( /Km) 0.3606 0.2575 0.1804 Breaking load (N) 19497 26880 37640

3.5.8TESTS The conductors shall be inspected and routine tested in accordance with the requirements of

BS 6485 and BS 125. The following tests shall be done at manufacturers works.

Tensile test Resistivity test Lay ratio of each layer Tensile strength Measurement of weight Resistance test

3.6 SPECIFICATIONS OF BARE COPPER CONDUCTORS. 3.6.1 SCOPE

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This specification is for copper conductors for earthing power distribution and transmission system.

This specification covers the following conductor sizes.

100Sq. mm stranded copper conductor

15 Sq. mm stranded copper conductor 3.6.2 REFERENCES

The following documents were referred to during the preparation of this specification, and may be referred to. In case of conflict, the provision of this specification shall take precedence.

Unless otherwise specified, the latest revision, edition and amendments shall apply.

BS 125: Hard – drawn copper and copper – cadmium conductors for overhead power

transmission purposes.

BS 4109: Specification for copper for electrical purposes. Wire for general electrical purposes and for insulated cables and flexible cords.

3.6.3 TERMS AND DEFINITIONS

For the purpose of this specification, the definitions in the reference standards shall apply.

3.6.4 SERVICE CONDITIONS See clause 1.5 3.6.5 MATERIALS

Copper wires used shall be high conductivity hard drawn copper wires.

The wires shall be clean, smooth and free from harmful defects. 3.6.6 CONSTRUCTION 3.6.6.1 The conductor shall be manufactured as per BS 125. 3.6.6.2 The conductor shall be concentrically stranded, with successive layers in opposite direction

of lay, but such that the outer layer shall be in the right hand spiral. The wires in each layer shall be evenly and closely stranded.

3.6.7STANDARD SIZES

The Standard Sizes for copper conductors shall be as follows:-

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CONDUCTOR Nominal Area of Copper (mm²) 100 150 Approximate overall diameter (mm). 12.9 16.0 Stranding No/mm 7/4.30 19/3.2 Calculated maximum d.c. resistance at 20°C ( /Km) 0.1804 0.1201 Breaking load (N) 37640 58690 Approximate mass of conductor (Kg/Km) 911.2 1376

3.6.8 TESTS

The conductors shall be inspected and routine tested in accordance with the requirements of BS 125.

3.7 33KV AND 11KV COMPOSITE INSULATORS 3.7.1 SCOPE 3.7.1.1 This specification is for composite insulators for use on overhead lines for tension and

suspension purposes. 3.7.1.2 This specification covers the following composite insulators.

(i) 11kV composite insulator (ii) 33kV composite insulator

3.7.2 REFERENCES

The following documents were referred to during the preparation of this specification.

In case of conflict, the provision of this specification shall take precedence. Unless otherwise specified, the latest revision, edition and amendments shall apply.

IEC 120: Dimensions of ball and socket couplings of string insulator units. IEC 815 Guide for the selection of insulators in respect of polluted conditions. IEC 1109: Composite insulators for ac overhead lines with a nominal voltage

greater than 1000V.

3.7.3 TERMS AND DEFINITIONS For the purpose of this specification, the definitions in the reference standards shall apply. 3.7.4 SERVICE CONDITIONS

See clause 1.5 3.7.5 MATERIAL AND CONSTRUCTION 3.7.5.1 The insulator shall have a core made of resin-impregnated glass fibre free from defects.

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3.7.5.2 The housing of the insulator shall be manufactured from high quality silicone. 3.7.5.3 The insulator shall be free from stresses due to expansion and contraction in any part, which

may lead to deterioration. 3.7.5.4 The insulator shall be of high resistance to moisture and ultraviolet radiation. 3.7.5.5 The insulator shall be fitted with ball and socket coupling in accordance to IEC 120. 3.7.5.6 The ball pin shall be of medium carbon steel. 3.7.5.7 The ball pin diameter shall be 16mm and shall be supplied separately with a corresponding

“R” form retaining clip. 3.7.5.8 The security clip shall be of stainless steel or an approved copper alloy. 3.7.6 CHARACTERISTICS The mechanical and electrical characteristics of the insulators shall be as follows:-

CHARACTERISTICS 11kV INSULATOR 33kVINSULATOR Dry Arc Distance 225 mm 385 mm Minimum Creapage Distance

300 mm 900 mm

Minimum Power Frequency Withstand Voltage (wet)

30 kV 70 kV

Minimum Lighting Impulse Withstand Voltage

95 kV 200 kV

Minimum Failing Load 70 kN 70 kN 3.8 SPECIFICATIONS FOR 33 KV AND 11KV PORCELAIN INSULATORS 3.8.1 SCOPE

i) This specification is for insulators for use on overhead power distribution lines operating at a nominal voltage of 33 kV.

ii) This specification covers the following standard insulators

(a) 33 kV pin insulators. (b) 33 kV line post insulators. Particular requirements for each insulator type as may be relevant for a specific requisition are given in section 4.

3.8.2 REFERENCES

The following documents were referred to during the preparation of this specification, and may be further consulted. In case of conflict, however, the provision of this specification shall take precedence.

Unless otherwise specified, the latest revision, edition and amendments shall apply. (a) IEC 720: Characteristics of line post insulators. (b) IEC 168: Tests on indoor and outdoor post insulators of ceramic material or glass for

systems with nominal voltages greater than 1000V. (c) IEC 815: Guide for the selection of insulators in respect of polluted conditions.

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(d) BS 137 Insulators of ceramic material or glass for overhead lines with a nominal

voltage greater than 1000V. Part 1 Methods of test Part 2 Requirements

3.8.3 TERMS AND DEFINITIONS For the purpose of this specification, the definitions in the reference standards shall apply. 3.8.4 SERVICE CONDITIONS

See clause 1.5 3.8.5 MATERIAL AND CONSTRUCTION 3.8.6 CONSTRUCTION 3.8.6.1 The insulating material shall be porcelain. 3.6.6.3 The porcelain shall be sound, free from flaws and blemishes, thoroughly vitrified, smoothly

glazed and of uniform brown colour when finished. 3.6.6.4 The insulator shall be free from stresses due to expansion and contraction in any part which

may lead to deterioration. 3.6.6.5 No chemical reaction between materials due to contact (e.g. between cement and metal

fittings) shall be allowed. 3.6.6.6 The under surface and grooves of sheds or skirts shall be easy cleaning. Sheds shall be

substantially symmetrical in shape without appreciable warping. 3.6.7 PARTICULAR REQUIREMENTS 1 Particular requirements for Pin Insulators The pin insulator shall have a cemented zinc thimble pin hole thread suitable for large steel

head pin in accordance with the requirement of BS 137 part 2. 2 Particular requirements for Line Post Insulators The line post insulator shall be of tie-top type with standard head suitable for both vertical

and horizontal mounting as per IEC 720. The insulator shall have a stud base suitable for mounting on a steel cross arm.

3 Particular requirements for Station Post Insulators The station post insulator shall have a plain base with tapped holes suitable for vertical

mounting on a steel channel. The top should have a provision for connecting a clamp or stacking a similar insulator at 76.2 mm (3”) P.C.D.

3.6.8 GENERAL CHARACTERISTICS

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The mechanical and electrical characteristics of the insulators shall be as follows:- 33kv 11kv Minimum failing load 10 kN 10KN Minimum creepage distance 900 mm 300mm Minimum wet power frequency withstand voltage

70kV (r.m.s.) 28kv

Minimum dry lightning impulse withstand voltage

170 Kv (peak) 75kv

3.6.8.1 TEST & INSPECTION Routine tests, type tests and sample tests of the particular insulator shall be done in accordance with the relevant requirements of BS 137 and IEC 168.

3.9 SPECIFICATIONS FOR LOW VOLTAGE INSULATORS 3.9.1 SCOPE This specification is for insulators for use on Low Voltage overhead lines and service lines operating at voltages up to and including 433 Volts. 3.9.2 REFERENCES The following documents were referred to during the preparation of this specification, and may be

further consulted. In case of conflict, however, the provision of this specification shall take precedence.

Unless otherwise specified, the latest revision, edition and amendments shall apply. (a) ES1 43-93: Line Insulators (b) BS 137: Insulators of ceramic material or glass for overhead lines with a nominal voltage greater than 1000V.

Part 1 Methods of test Part 2 Requirements

(c) BS 3288: Insulator and Conductor Fittings for Overhead Power Lines.

3.9.3 TERMS AND DEFINITIONS For the purpose of this specification, the definitions in the reference standards shall apply. 3.9.4 SERVICE CONDITIONS

See clause 1.5 3.9.5 MATERIAL AND CONSTRUCTION

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3.9.5.1 The insulating material shall be porcelain. The porcelain shall be sound, free from flaws and blemishes, smoothly glazed and of uniform brown colour when finished.

3.9.5.2 The insulator shall be free from stresses due to expansion and contraction in any part which may lead to deterioration.

3.9.5.3 The hole in the insulator shall be smoothly radiused to present an even bearing surface to the steel bolt.

3.9.5.4 The insulator shall be of reel type. 3.9.6 GENERAL CHARACTERISTICS The dimensional, mechanical and electrical characteristics of the insulator shall be as follows:- Length of insulator--------------------------------------------------------------65mm Outer diameter of insulator-----------------------------------------------------76mm Diameter of through hole-------------------------------------------------------17.5mm Conductor groove diameter----------------------------------------------------9.5mm Minimum failing load-----------------------------------------------------------15kN Minimum wet flashover voltage-----------------------------------------------9kV Minimum dry flashover voltage-----------------------------------------------17kV 3.9.6.1 MARKING

The following information shall be clearly and indelibly marked on the porcelain insulator. Name and trade mark of the manufacturer Year of manufacturer The marking may be printed or impressed provided such impression do not impair the performance of the insulator.

3.9.7 TESTS 3.9.7.1 The finished insulator shall be tested in accordance with the requirements of this clause. 3.9.7.2 Verification of Dimensions

The dimension of the sample insulator shall be those stated in clause 5.1 with a tolerance of 5%.

3.9.7.3 Mechanical Failing Load

The insulator shall be mounted on an M16 bolt of adequate length in a rigidly held bracket. A flexible wire rope of not less than 12mm diameter shall be looped round the conductor groove, and shall be pulled at right angles to the bolt of the insulator bracket and in line with the bracket. The load shall be increased up to 15 kN at a steady rate and held at this load for a period of not less than 10 seconds.

This test shall not cause fracture of the insulator.

3.9.7.4 Porosity Test The insulator shall be tested in accordance with BS 137, Part 1 Clause 4-8. 3.9.7.5 Mechanical Failing Load

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Test Certificates certified by the National Testing or the National Standards Institute of the country of origin. shall accompany material to KPLC stores while sample copies for similar material shall be presented with the tender for the purpose of technical evaluation.

3.10 SPECIFICATIONS LINE SUPPORTS AND FOUNDATION

The network shall be supported on wood poles, however alternative supports such as concrete and steel structures may be considered. The wood poles shall meet specifications set in Kenya Standard KSO2-516: Poles for power and telecommunications lines.

3.10.1PHYSICAL AND MECHANICAL PROPERTIES

The wood poles used shall have the following properties:-

Nominal length

11 11 12 12 14 14

Category Medium

Stout Medium Stout Medium Stout

H(mm) 1.8 1.8 1.8 1.8 2.0 2.0 Dc(mm) 230 295 240 305 248 310 Dm(mm) 160 200 160 200 160 200 Dg(mm) 230 295 240 305 270 335 De(mm) 185.6 234.8 189 238.1 199.4 248.4 F(kN) 4.94 13.05 4.03 10.37 3.45 8.23 Ultimate load (kN)

8.73 18.42 8.89 18.24 10.46 20.02

Crippling load (kN)

58.6 149.8 51.2 128.9 45.9 110.3

H Ground position from butt dc Critical diameter dg Minimum groundline diameter (mm) dm Minimum top diameter (mm) de Effective diameter f Load per mm of deflection at point of application of load Note that the mechanical properties used in the mechanical calculations are those stated in the

Kenya Standard KSO2-516. 3.10.2 STRENGTH AND SPECIES Wood poles shall belong to the strength groups Light, Medium, stout as specified. 3.10.3 MOISTURE CONTENTS The average moisture content of a pole at the time of impregnation shall not exceed 25% and

shall not fall below 20%. 3.10.4 DEFECTS

i) The radial width of the sapwood shall not be less than 15mm.

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ii) Poles shall be straight and sound and shall be free from wood decay, sap, rot, large or dead knots and excessive splits or checks. There shall be no splits or checks across the butt end.

iii) Poles shall be free from insect damage and fungal attack.

3.10.5 DIMENSIONS i) The lengths shall conform to specified nominal lengths with a tolerance of 75mm. ii) The diameter of the pole shall conform to the values specified therein with a tolerance

of 20mm for light and medium poles and 25mm for stout poles. iii) Holes drilled in the pole to support fittings shall have a diameter of 18mm for pole sizes

8.5m and 10.0m and 24mm for all other sizes with a tolerance of 1mm. iv) Each pole shall contain the natural butt of the tree (which shall be as close to the ground

as possible when the tree is felled) and shall not be trimmed or cut from the butt end to reduce its natural size. The ends shall be free from steps and butt end shall be cut square to within 5o which the top end shall be cut to an apex of 45o + or –5o.

v) Shaping and cutting of the poles shall be carried out before impregnation. Poles shall be shaved free of the bark, and branches shall be cut off neatly in the direction of growth and be dressed down flush with the trunk before impregnation.

vi) When a hole is drilled in the factory, it shall be drilled before treatment and a template shall be used to mark off the hole positions. The template shall be placed parallel to the effective centre line of the pole to ensure that the cross arm or other fittings are plumb when the pole is erected.

3.10.6 IMPREGNATION

i) Drilling and scarfing shall be done before impregnation. ii) The average moisture content of the pole at the time of impregnation shall not exceed

25% and shall not fall below20%. iii) Impregnation shall be carried out in the vacuum – cell pressure process according to

Kenya Standard KS02-94. iv) Preservative used shall be creosote or CCA and shall comply with the requirements of

Kenya Standard KS02-94. v) Retention shall not be less than 80Kg/M3 and shall be complete in sapwood.

3.10.7 BANDING Both ends of the pole shall be banded before impregnation. The shortest distance from the nearer end of the pole to the band tape shall not be less than

75mm and not more than 100mm. The pole shall be banded by use of galvanized steel tape not less than 0.9mm thick (SWG 20)

and 19mm wide fastened tightly around the pole and secured by a suitable clip and galvanized wire nails.

3.10.8 STANDARD POLE SIZES The standard sizes of the different categories of poles shall be as follows:-

6.4.8.1 LIGHT POLES

STANDARD LENGTH (m)

MINIMUM GROUND LINE

MINIMUM TOP DIAMETER (mm)

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DIAMETER (mm) 11.0 190 140 12.0 200 140

6.4.8.2 MEDIUM POLES

STANDARD LENGTH (m)

MINIMUM GROUND LINE DIAMETER (mm)

MINIMUM TOP DIAMETER (mm)

11.0 230 160 12.0 240 160 14.0 270 160

6.4.8.3 STOUT POLES

STANDARD LENGTH (m)

MINIMUM GROUND LINE DIAMETER (mm)

MINIMUM TOP DIAMETER (mm)

11.0 295 220 12.0 305 220 14.0 335 230 15.0 360 230 17.0 375 230

3.10.9 MARKINGS

i) The poles shall be marked legibly and indelibly at a distance of 3.0m +or Minus 150mm form the butt end.

ii) Identification tags shall be at least 60mm x 35mm in size and shall be of aluminium of thickness not less than 0.9mm (SWG 20).

iii) The identification shall be stamped with the following information:- a) Identification mark or name of the plant where the pole was treated. b) Date of treatment comprising first two digits of the month and last two digits of the

year. c) Length of pole in meters. d) Category of pole by first letter (Light, Medium, Stout).

The letters and figures shall be at least 10mm high.

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3.10.10 TESTING i) Testing method with regard to preservation shall be in accordance with the

requirements of Kenya Standard KS02-94. ii) Determination of dimensions and strengths shall be in accordance with the requirement

of Kenya Standard KS02-516. iii) All tests on pole shall conform to the limits specified I this specification.

3.10.11 EXCAVATION The hole for the pole shall be excavated to a minimum of 1.8m for the 11m pole. If the base

of the hole is not firm ground, the hole shall be excavated until firm ground is reached, otherwise murram base shall be prepared.

The minimum hole depth for wood poles shall be defined in the table:-

Pole Height H (m)

Size Hole Depth Minimum (m)

11 Medium 1.8 11 Stout 1.8 12 Medium 2.0 12 Stout 2.0 14 Medium 2.2 14 medium 2.2

The hole shall be dug to the required depth. Any holes left overnight must be covered in such

a way that they do not pose any danger to persons or animals. A suitable method of warning shall be used to identify positions of the holes.

3.10.12 BACK FILLING The soil to be used to fill the foundation after the pole has been inserted shall be the

excavated soil unless the soil is found unsuitable. In this case fill shall be imported from the nearest suitable place.

The foundation fill shall be compacted manually in layers. These layers shall not exceed 150mm so as to allow for compaction to an acceptable degree.

In areas where the ground is unsuitable for firm erection of poles ie. swampy areas with black cotton soil etc kicking blocks can be used to reinforce the foundation.

3.11 SPECIFICATIONS FOR STAY, STAY INSULATORS AND STAY BLOCKS 3.11.1 SCOPE i) This specification is for stay insulators for use on overhead power distribution lines operating

at a nominal voltage of up to 33 kV. ii) This specification covers the following standard insulators

(a) Stay insulator for Low Voltage lines. (b) Stay insulator for 33kV Voltage lines. Particular requirements for each insulator type as may be relevant for a specific requisition are given in section 4.

81

3.11.2 REFERENCES

The following documents were referred to during the preparation of this specification, and may be further consulted. In case of conflict, however, the provision of this specification shall take precedence.

Unless otherwise specified, the latest revision, edition and amendments shall apply. (a)IEC 720: Characteristics of line post insulators. (b)IEC 168: Tests on indoor and outdoor post insulators of ceramic material or glass for systems with nominal voltages greater than 1000V. (c )IEC 815: Guide for the selection of insulators in respect of polluted conditions. (d)BS 137 Insulators of ceramic material or glass for overhead lines with a nominal voltage greater than 1000V.

Part 1 Methods of test Part 2 Requirements

(e) ESI.43-91 - Stay strands and stay fitings for overhead lines.

3.11.3 TERMS AND DEFINITIONS For the purpose of this specification, the definitions in the reference standards shall apply. 3.11.4 SERVICE CONDITIONS

See clause 1.5 3.11.5 MATERIAL AND CONSTRUCTION 3.11.6 CONSTRUCTION 3.11.1.1 The insulating material shall be porcelain. 3.11.1.2 The porcelain shall be sound, free from flaws and blemishes, thoroughly vitrified,

smoothly glazed and of uniform brown colour when finished. 3.11.1.3 The insulator shall be free from stresses due to expansion and contraction in any part

which may lead to deterioration. 3.11.1.4 The holes in the insulator shall be smoothly radiused with as large a radius as practicable

to present an even bearing surface to the stay strand loop. 3.11.7PARTICULAR REQUIREMENTS a) Particular requirements for Low Voltage stay Insulators The insulator shall be sling type strain insulator suitable for stay wire size 7/4.00m. The

minimum failing load shall be 48 kN The minimum dry lightning impulse withstand voltage 20 kV b) Particular requirements for 11kV stay Insulators The insulator shall be string type strain insulator suitable for stay wire size 19/3.55mm. The minimum failing load shall be 110kN.

Minimum wet power frequency withstand voltage 20 kV (r.m.s.)

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Minimum dry lightning impulse withstand voltage 60 kV(peak) c) Particular requirements for 33kV stay Insulators The insulator shall be string type strain insulator suitable for stay wire size 19/3.55mm. The minimum failing load shall be 110kN.

Minimum wet power frequency withstand voltage 48 kV (r.m.s.) Minimum dry lightning impulse withstand voltage 100 kV(peak)

3.11.8 STAY 3.11.8.1 SCOPE

This specification covers the design, manufacture testing and supply of galvanized stranded steel wire for use as stays and for similar purposes on overhead power distribution lines.

This specification covers the following steel wire sizes. 7/4.00/700 Stranded Stay Wire 19/3.55/700 Stranded Stay Wire 7/2.00/700 Stranded Stay Wire 4/4.00/700 Stranded Stay Wire

3.11.8.2 REFERENCES

The equipment shall comply with the latest edition and amendments of the Standards listed herein. BS 183:Specification for general purpose galvanized steel wire strand. BS 443:Specification for testing zinc coatings on steel wire and for quality requirements. ANS C7.46:Standard specification for zinc-coated steel wire strand. ES1 43-91:Stay strands and stay fittings for overhead lines.

3.11.8.3 MATERIAL

(a) The base metal shall be steel made by the open-hearth, basic-oxygen or electric-furnace process and of such quality and purity that, when drawn to the size of wire specified and coated with zinc, the finished strand and the individual wires shall be of uniform quality and have the properties and characteristics as specified in this specification.

(b) The galvanized steel wires used in the construction of the stay wire shall comply with

the requirement of BS 443. 3.11.8.4 CONSTRUCTION

(a) The stay wire shall be manufactured as per the requirement of BS 183.

83

(b) The outer wires of all strands shall have a right-hand lay (Z).

(c) All wires shall be stranded with uniform tension. Stranding shall be sufficiently close

to ensure no appreciable reduction in diameter when stressed to 10% of the specified wire strength.

(d) The wires shall be concentrically twisted with a uniform pitch of not less than 10 nor

more than 18 times the specified nominal diameter of the strand.

(e) Joints made in individual wires shall be accepted provided there is not more than one joint in any 45m section of the completed strand.

Joints made during stranding shall be protected against corrosion.

3.11.8.5 STANDARD SIZES

The standard sizes for the stay wires shall be as follows:-

STANDARD NEAREST EXISTING SIZE SIZE GRAD

E MINIMU

M BREAKI

NG LOAD

KPLC CODE

SIZE QUALITY

MINIMUM BREAKING

LOAD

7/4.00 700 61.6 kN 89737 7/8 Stay Wire

45 ton/in2 6430 kg

19/3.55

700 131.6 kN 89739 19/10 Stay Wire

45 ton/in2 11180 kg

7/2.00 700 15.4 kN 89743 7/14 Stay Wire

45 ton/in2 1610 kg

4/4.00 700 35.2 kN 89748 4/8 Stay Wire

45 ton/in2 3680 kg

3.11.8.6 TESTS

The diameter of the wires shall be tested in accordance with the requirement of BS 183. Tensile test, Elongation test and wrapping test shall be done in accordance with the requirement of BS 183. Uniformity, adherence and mass of coating shall be tested as per BS 443.

3.11.8.7 PACKING

84

The complete stay wire shall be rolled in a coil and packed in a manner as to protect it from any damage in transportation and repeated handling. The completed coil shall be tagged. The following description shall be marked on the tag. Type of stay wire. Length. Manufacturer’s name. Year of manufacture.

2 STAY RODS AND TURNBUCKLES 3.11.8.8 SCOPE

This specification covers the design, manufacture testing and supply of tubular stay rods and turnbuckles for use on stays and for similar purposes on overhead power distribution lines. This specification covers the following sizes:

(a) Tubular Stay Rods:

6ft x 5/8” 8ft x ¾” 9ft x 1”

(b) Turnbuckle double eye bolt:

10” x 5/8” 12” x ¾” 10” x ⅞”

3.11.8.9 REFERENCES

The equipment shall comply with the latest edition and amendments of the Standards listed herein. BS 464: Specification for thimble for wire ropes. BS 729: Specification for hot dip galvanized coating on iron and steel articles. BS 1387: Specification for screwed and socketed steel tubes and tubulars and for

plain and steel tubes suitable for welding or screwing to BS 21 pipe threads.

BS 3643: ISO metric screw threads. BS 4360: Specification for weldable structural steels.

85

3.11.8.10 MATERIAL

(a) Tubular Stay Rods

The tubular turnbuckle (the tube portion of the adjustable rod) shall be manufactured from heavy gauge steel tube as specified in BS 1387, table 3. The threads shall be to BS 3643, coarse pitch, tolerance class 7H/8g (free fit). The screw-in stay anchor and the adjustable head shall be manufactured from Grade 43A steel as specified in BS 4360. The thimble shall be manufactured from standard crescent shaped steel bar as used for thimbles to BS 464.

(b) Turnbuckle double eye bolt

The turnbuckle shall be manufactured from Grade 43A steel as specified in BS 4360. The Threads shall be to BS 3643, course pitch tolerance class 7H/8g (free fit)

3.11.8.11 CONSTRUCTION

(a) Tubular Stay Rods

The tubular turnbuckle shall have hexagon head, solid forged on one end of tube. The stay anchor and the adjustable head shall have hexagon lock nuts of the same size as the hexagon head of the tubular turnbuckle. The lower end of the stay anchor shall be forged square to fit square plate. The square plate shall be 100mm by 100mm by 6mm in dimension, for securing the rod to a concrete stay block. The stay adjustable head shall have a forged eye with a thimble suitable for the specified stay wire sizes. The stay rod assembly shall be galvanized to BS 729. The complete stay rod assembly shall have the minimum failing load as stated in clause 5.

(b) Turnbuckle double eye bolt

The turnbuckle shall have a forged eye bolt at each end and shall be supplied complete with hexagon lock nuts. The turnbuckle shall be double screw threaded in opposite directions to achieve simultaneous adjustment/tightening. The complete turnbuckle assembly shall be galvanized to BS 729 and have the minimum failing load as stated in clause 5.

86

3.11.8.12 STANDARD SIZES (a) The standard sizes for the Tubular Stay Rods shall be as follows:-

KPLC CODE SIZE MINIMUM FAILING LOAD

SIZE OF STAY WIRE

186525 6ft x 5/8”

36.8 kN 4/8 stay wire

186531

8ft. x ¾”

64.3 kN 7/8 stay wire

186533 9ft. x 1”

131.6 kN 19/10 stay wire

(b) The standard sizes for the Turnbuckles (double eye bolt) shall be as follows:-

KPLC CODE SIZE MINIMUM FAILING LOAD

SIZE OF STAY WIRE

189306 10” x 5/8”

36.8 kN 4/8 stay wire

189307

12” x ¾”

64.3 kN 7/8 stay wire

189308

10” x 7/8”

131.6 kN 19/10 stay wire

3.11.8.13 TESTS

The complete Tubular Stay Rod and Turnbuckle shall be tested to determine the minimum failing load. Uniformity, adherence and mass of coating of the galvanizing shall be done in accordance with BS 729.

3.11.9 STAY BLOCK A reinforced concrete stay block buried to the depth of at least 1.4m shall be used as the stay

anchor. 3.12 SPECIFICATIONS FOR FASTENERS AND WASHERS FOR OVERHEAD LINES 3.12.1 SCOPE.

a) This specification is for fasteners and washers for use on standard overhead power lines constructed on wood pole supports.

b). This specification covers the following items.

(i) Pole bolts and Nuts

(ii) Assembly Bolts and Nuts

(iii) Eye Bolts and Nuts

(iv) Tie rods

87

(v) Washers

(vi) Screws

(vii) Nails

(viii)Staples

3.12. 2 REFERENCES

The following documents were referred to during the preparation of this specification and unless specified, the latest revision, edition and amendments shall apply:

BS 729 Hot dip galvanised coating on iron and steel articles

BS 3692 ISO Metric precision hexagon Bolts, Screws and Nuts

BS 4190 ISO Metric black hexagon Bolts, Screws and Nuts

BS 3643 ISO Metric screw threads

ESI 43 - 96 Fasteners and Washers for wood pole overhead lines In case of conflict, the provisions of this specification shall take precedence

3.12.1 TERMS AND DEFINITIONS

For the purpose of this specification, the definitions in the reference standards shall apply.

3.12.2 SERVICE CONDITIONS

As stated in clause 1.5

3.12.3 MATERIALS AND FABRICATION

3.12.3.1 Pole bolts, assembly bolts, eye bolts and tie rods shall be manufactured as per the

requirement of BS 4190, grade 4.6 for bolts.

3.12.3.2 All bolts shall be fitted with associated nut.

3.12.3.3 Nuts shall be manufactured as per the requirement of BS 4190, grade 4.

3.12.3.4 The bolts shall be ISO metric, black, hexagon bolts and shall be galvanised.

3.12.3.5 All bolts and nuts shall be hot dip galvanised and shall fulfil all the requirement of BS

729.

3.12.3.6 Eye bolts shall be drop forged in manufacture, and shall be complete with one full

3.12.3.7 Where any welding process is used in the manufacture of an eye bolt, the joint between the eye piece and the bolt rod shall first be threaded in the same way as the nut end of the rod, and the complete eye bolt shall be proof tested to 125 per cent of its safe working tensile load. The safe working tensile load shall be the ultimate axial tensile strength divided by a factor of safety of 2.5.

3.12.3.8 All washers, round and square, with curved or flat surfaces, shall be made from mild steel as per BS 4320.

88

3.12.3.9 Washers shall be suitable for use with bolts of sizes 1/2, 5/8 or 3/4 of an inch (M12,

M16 or M20, respectively).

3.12.4 DIMENSION AND SIZES

3.12.4.1 All bolts shall have a safe working shear stress of not less than 120 N/mm2 ; the ultimate shear stress shall be 75% of the ultimate tensile strength, the factor of safety being not less than 2.5.

3.12.4.2 The bolts shall be have threads of coarse pitch, free fit, class 7H/8g as per BS 3643.

3.12.4.3 The length of thread on bolts shall be in accordance with BS3692. For double threaded bolts (bolts without head), the length of threads on both sides shall be equal and in accordance with BS 3692.

3.12.4.4 Ultimate tensile strength and tensile stress for the bolts for different bolt sizes shall be as indicated in Table I below:

TABLE I

Bolt Sizes

Ultimate Tensile Stress

Tensile Stress Area

Ultimate Tensile

Strength

Safe Working

Load

Safe Working

Shear Load

Imperial Metric N/mm2 mm2 kN kN kN

½ inch M12 392 84.3 33.05 13.22 9.91

5/8 inch M16 392 157.0 61.54 24.62 18.46

¾ inch M20 392 245.0 96.04 38.42 28.81

3.12.5 TESTS 3.12.5.1 The tensile strength, yield stress and elongation tests shall be done in accordance with

the requirement of BS 4190. 3.12.5.2 Test on galvanising shall be carried on the finished bolt in accordance with the

requirement of BS 729. 3.12.5.3 Test reports shall be completed and made available for approval before shipment of

the materials.

3.12.6 MARKING AND INFORMATION

3.12.6.1 The following information shall be marked indelibly and legibly on the fasteners:

i) Manufacturers name or trademark ii) Strength grade designation.

89

APPENDIX APPLICATION OF BOLTS AND NUTS

TABLE I: STRAIGHT BOLTS

BOLT SIZE NORMAL BASIC APPLICATION

STANDARD SIZE NEAREST EXISTING

SIZE

Diameter Designati

on

Nominal

Length

(Length x Diameter)

(mm) (Inches)

M12 40 11/2 x 1/2 Substation assembly M12 75 3 x 1/2 Substation assembly M12 130 5 x 1/2 PC 400 Transformer fuses on small fuse

bar M12 180 7 x 1/2 PC 400 Transformer fuses on wide fuse

bar M16 110 41/2 x 5/8 LV shackle pin, small M16 130 5 x 5/8 LV shackle pin, large

M16 180 7 x 5/8 Pole Bolt M16 240 9 x 5/8 Pole Bolt M16 280 11 x 5/8 Pole Bolt M16 325 13 x 5/8 Pole Bolt

M16 350 14 x 5/8 Pole Bolt M16 375 15 x 5/8 Pole Bolt M16 400 16 x 5/8 Pole Bolt

M20 40* 11/2 x 3/4 Tie strap, steel cross arm

M20 50* 2 x 3/4 Steel cross arm

M20 75 3 x 3/4 Assorted use

M20 100 4 x 3/4 Assorted use

M20 130 5 x 3/4 Cross arm

M20 150 6 x 3/4 Assorted use

M20 180 7 x 3/4 Cross arm

To fit “D”- irons to various 28 ft and 32 ft light and medium pole choices.

For direct mounting of shackle insulators (with no “D”- irons fitted).

90

M20 240 9 x 3/4 Pole Bolt

M20 280 11 x 3/4 Pole Bolt

M20 325 13 x 3/4 Pole Bolt

M20 350 14 x 3/4 Pole Bolt

M20 400 16 x 3/4 Pole Bolt

M20 450 18 x 3/4 Pole Bolt

M20 500 20 x 3/4 Pole Bolt

M20 560* 22 x 3/4 Pole Bolt

M20 600* 24 x 3/4 Pole Bolt

M20 560* 22 x 3/4 Pole erection

* These sizes are non-standard.

TABLE II: EYE BOLTS

BOLT SIZE NORMAL BASIC APPLICATION

STANDARD SIZE NEAREST EXISTING SIZE

Diameter Designation

Nominal Length

(Length x Diameter)

(mm) (Inches)

M16 250 10 x 5/8 Pole Bolt

M16 300 12 x 5/8 Pole Bolt M16 450 18 x 5/8 Pole Bolt

M20 250 10 x ¾ Pole Bolt M20 350 14 x ¾ Pole Bolt

TABLE III: DOUBLE THREADED BOLTS

BOLT SIZE NORMAL BASIC APPLICATION

STANDARD SIZE NEAREST EXISTING SIZE

Diameter Designation

Nominal Length

(Length x Diameter)

(mm) (Inches)

M20 560 22 x 3/4 Pole Bolt

To fit single or double cross-arm of sizes 3” up to 5”, post insulators and other fittings to various pole choices of 36 ft up to 55 ft mostly of medium and stout categories.

For fittings on terminal and vertical poles of various sizes.

For fittings on terminal and vertical poles of various sizes.

For fittings on horizontal section poles.

91

3.13 SPECIFICATIONS FOR OVERHEAD LINES FITTINGS 3.13.1 SCOPE a) This specification is for overhead line fittings for use on overhead power lines operating at voltages up to and including 66 kV (66000 volts) a.c. b) This specification covers the following overhead line fittings:-

Conductor terminations. Joints (Non-tension joints). Suspension clamps. Connectors

5'' /8

25

( 8'' )

CODE 189306 TURN BUCKLE DOUBLE

EYEBOLT SWIVEL 254 x 16mm. (10''x )

204

16mm eyeboltone thread to be clockwise& the other one to be anti-clockwise

R = 11mm

R = 23mm R = 23mm

R = 11mm

48

( 10'' )254

92

Particular requirements for each type of fittings as may be relevant for a specific requisition are given in clause 4.3.

3.13.2 REFERENCES

The following documents were referred to during the preparation of this specification and may be referred to. In case of conflict, the provision of this specification shall take precedence.

Unless otherwise specified, the latest revision, edition and amendments shall apply. BS 729: Hot dip galvanized coating on iron and steel articles. BS 3288: Insulator and conductor fittings for overhead power lines.

Part 1: Performance and general requirements. Part 2: Dimensions.

ESI 43-92: Conductor termination’s, joints and insulator binds for overhead up to and including

132 kV. 3.13.3 TERMS AND DEFINITIONS For the purpose of this specification, the definitions in the reference standards shall apply. 3.13.4 SERVICE CONDITIONS See clause 1.5 3.13.5 MATERIAL AND CONSTRUCTION 3.13.5.1 The fittings shall be free from defects which would be likely to cause them to be

unsatisfactory in service. 3.13.5.2 All parts of fittings shall be either inherently resistant to atmospheric corrosion, both

during storage and in service. 3.13.5.3 All ferrous metal parts except those made of stainless steel shall be protected by hot

dip galvanizing as per the requirement of BS 729. 3.13.5.4 The threads of nuts and tapped holes shall be cut after galvanizing and shall be well

oiled or greased. All other threads shall be formed before galvanizing. 3.13.6 PARTICULAR REQUIREMENTS a) Conductor Termination’s. Ball ended hook, Socket clevis and Socket tongue 3.13.6.1 Ball ended hook, Socket clevis and Socket tongue shall be suitable for use on

Aluminium conductor steel-reinforced (ACSR) of outer diameter between 7.00 mm and 18.2 mm (25 sq. mm and 150 sq. mm) and standard disc insulator of ball and socket type with the ball pin diameter of 16 mm.

3.13.6.2 Ball ended hook, socket clevis and socket tongue shall be of malleable iron or ductile iron, hot dip galvanised to BS 729.

Tension clamp

93

3.13.6.3 Tension clamp shall be bolted type and shall be suitable for use on aluminium

conductor steel-reinforced (ACRS) of outer diameter between 7.00 mm and 18.2 mm (25 sq. mm and 150 sq. mm).

3.13.6.4 The clamp body and keeper piece shall be of high strength and heat treated cast

aluminium alloy. 3.13.6.5 The clamp cotter bolts, and U-bolts shall be galvanised steel and the pin shall be

stainless steel. 3.13.6.6 The clamp shall have slip strength of not less than 85% of the rated ultimate strength

of conductor it is intended for use with. b) Joints (Non-tension) Parallel groove clamp (PG Clamp ) 3.13.6.7 Parallel groove clamp (PG Clamp ) shall be suitable for use on aluminium conductor

steel-reinforced and all aluminium conductors of outer diameter in the range of 7.00 mm to 18.2 mm for ACSR conductors and 9.0 mm to 13.2 mm for AAC conductors (25 sq. mm and 150 sq. mm). (a) The groove of the PG clamp shall correctly fit the conductor it is intended for use with. It

shall have adequate cross sectional area and length. (b) The PG clamp shall be of electrolytic, high strength, corrosion resistant aluminium alloy.

c) Suspension Clamps 3.13.6.8 Suspension clamps shall be suitable for use on aluminium conductor steel-reinforced

(ACSR) of up to 18.2 mm diameter (150 sq. mm) and shall be of the following types.

(a) Clevis ended hook type and pivoted type (similarly known as envelope type and trunnion type respectively).

(i) The clamp body and keeper piece shall be of high strength, heat-treated cast

aluminium alloy. (ii) The clamp cotter bolts, hangers, brackets and U-bolts shall be of galvanised steel and

the cotter pin shall be of stainless steel.

(b) Angle suspension clamp type (similarly known as side opening type).

(i) The clamp shall be suitable for use on turning angles from 10 to 120 degrees. (ii) The clamp body and keeper shall be of malleable iron or ductile iron, hot dip

galvansed to BS 729. (iii) The clamp cotter bolts and bolt shall be galvanised steel and the cotter pin shall be

stainless steel.

d) Connectors

94

3.13.6.9 The connectors shall be suitable for use on stranded bare conductors and shall

correctly fit the conductor it is intended for use. 3.13.6.10 The connector shall have adequate cross sectional area and dimensions and shall have

current carrying capacity at least equal to the capacity of the conductor it is intended for. (a) Aluminium connectors

(i) Aluminium connectors (line taps) shall be suitable for connecting stranded aluminium conductors

(ii) The connector shall be manufactured from electrolytic, high strength aluminium.

(b) Copper connectors

Copper connectors shall be suitable for connecting stranded copper conductors.

(c) Bi-metal connectors

(i) Bi-metal connectors shall be suitable for connecting stranded aluminium conductors to stranded copper conductors.

(ii) The bi-metal connector shall be designed to provide an effective corrosion barrier between the dissimilar metals (aluminium and copper).

3.13.6.11 MARKING

Each fitting shall be stamped with the type number and metric conductor size with which it is to be used.

3.13.7 TESTS

The fittings shall be tested as per BS 3288.

APPENDIX TABLE I: TERMINATION’S (TENSION JOINTS)

KPLC CODE DESCRIPTION NORMAL BASIC APPLICATION

184 501 Ball ended hook to BS 3288 Ref. 15/81

Termination of conductors above 50 sq. mm and up to 100 sq. mm

180 116 Socket tongue to BS 3288 Ref. 15/81

Termination of conductors up to 50 sq. mm

180 121 Socket tongue to BS 3288 Ref.15/35

Termination of conductors above 50 sq. mm and up to 100 sq. mm

180104 Ball clevis For section pole construction for conductors of up to 50 sq.

95

mm 180111 Socket clevis For vertical flying angle and

section pole construction 181 920 Terminating clamp

3 – U bolt For terminating ACSR conductors of up to 100 sq. mm

181 928 Terminating clamp 4-U bolt

For terminating ACSR conductors above 100 sq. mm

TABLE II: NON - TENSION JOINTS

KPLC CODE DESCRIPTION NORMAL BASIC APPLICATION 181813 P.G. Clamp (2 bolted)

For 25 sq. mm ACSR conductor

181816 P.G. Clamp (3 bolted)

For 75 sq. mm ACSR conductor

181817 P.G. Clamp (4 bolted) For 150 sq. mm ACSR conductor TABLE III: SUSPENSION CLAMPS

KPLC CODE DESCRIPTION NORMAL BASIC APPLICATION

181903 Clevis ended hook type suspension clamp (envelop type)

For 33kV suspension type construction

181906 Pivoted type suspension clamp (Trunnion Type)

For 33kV suspension type construction

181926 Angle type suspension clamp (Side opening type)

For vertical flying angle construction

TABLE IV: CONNECTORS

KPLC CODE DESCRIPTION NORMAL BASIC APPLICATION

Aluminuim connectors 188742 Line tap For 50 sq. mm AAC conductor 188743 Line tap For 100 sq. mm AAC conductor Copper connectors Copper service line tap For 25 sq. mm Copper conductor Copper service line tap For 50 sq. mm Copper conductor Bi-metal connectors Bi-metal Connector line tap For conductor size 50 sq. mm Bi-metal Connector line tap For conductor size 100 sq. mm

96

3.14 SPECIFICATIONS FOR BINDING WIRES AND STIRRUPS 3.14.1 SCOPE 3.14.1.1 This specification covers the requirement for insulator binding wires and stirrups for

use on overhead power distribution lines. 3.14.1.2 This specification covers the following binding wires and stirrups:-

(i) Binding wire for low voltage lines. (ii) Binding wire for medium voltage lines. (iii) Stirrups for medium voltage lines.

3.14.2 REFERENCES The documents named below were referred to during the preparation of this specification.

Incase of conflict, the provision of this specification shall take precedence. Unless otherwise specified, the latest revision, edition and amendments of the referred documents shall apply. BS 1475: Wrought Aluminium and aluminium alloys for general engineering

purposes – wires. BS 2627: Wrought Aluminium for electrical purposes – wires. BS 6746: PVC insulation and sheath of electric cables. ESI 43-92: Conductor terminations, joints and insulator binds for overhead lines

up to and including 132 kV. 3.14.3 SERVICE CONDITIONS See clause 1.5 3.14.4 MATERIAL 3.14.4.1 The binding wire shall be 3.66mm diameter (SWG 9) plain aluminium bare conductor

to BS 2627, condition H8 for use with bare aluminium and ACSR conductors. 3.14.4.2 The binding wire for use with PVC covered conductors shall be covered with 0.5mm

black PVC to BS 6746 type 1. 3.14.4.3 The stirrups shall be cold formed such that the bends shall be smooth and the stirrup

free from indentations. 3.14.4.4 The stirrup shall be 7.0mm diameter aluminium rod to BS 1475, designated GIB

condition H8. 3.14.5 TESTS

97

The binding wires and stirrups shall be tested in accordance with the requirements of this specification, otherwise as per the relevant requirements of BS 2627, BS 6746 and BS 1475 as applicable.

3.15 SPECIFICATIONS FOR POLE SIGNS AND ACCESSORIES 3.15.1 SCOPE 3.15.1.1 This specification is for Pole Signs and Accessories for use on overhead lines

operating at voltages above 1000 volts. 3.15.1.2 The specification covers the following items:

a) Danger Hatari Plate b) Danger Plate c) Pole Number Plate

d) Substation Number Plate

e) Protective Multiple Earthing Plate

3.15.2 REFERENCES The following documents were referred to during the preparation of this specification; in case of conflict, the requirements of this specification take precedence.

British Standard Colours for Specific Purposes

3.15.3 DEFINITIONS

The definitions given in the reference standard apply.

3.15.4 REQUIREMENTS

Operating Conditions

See clause 1.5 of technical specifications (volume 2)

3.15.5 DESIGN AND CONSTRUCTION 3.15.5.1 All plates shall be 1.5mm thick aluminium vitreous enamelled in colours indicated.

Back of plate to be enamelled black at works.

3.15.5.2 Colours for symbols shall be to the following numbers as per BS 381C:

a) RED: Colour No. 538, Post Office Red

b) YELLOW: Colour No. 355, Lemon

98

3.15.5.3 The lettering, signs and background of the various plates shall be as follows:

Item Signs and Letters Background Danger Hatari

Plate RED WHITE

Danger Plate RED WHITE Pole Number Plate BLACK WHITE Substation Number Plate BLACK WHITE Protective Multiple Earthing Plate

RED YELLOW

3.15.5.4 Dimensions shall be as per the drawings attached (all dimensions in mm).

The substation number plate shall be similar to the pole number plate in design but double in width to accommodate four figures e.g. 0012. The series of numbers required shall be given with the order.

3.15.5.5 The pole signs and accessories shall have a service life of at least ten years.

3.15.6 TESTS

Tests for the Pole Signs and Accessories shall be in accordance with the requirements of this specification.

3.16 CONDUCTOR SLEEVE JOINT 3.16.1 SCOPE 1.1 This specification is for conductor sleeve joint for use on overhead power lines operating at

voltages up to and including 66 kV (66000 volts) a.c.

3.16.2 SERVICE CONDITIONS

See clasuse 1.5

3.16.3 MATERIAL AND CONSTRUCTION 3.16.3.1The sleeve joints shall be free from defects which would be likely to cause them to be

unsatisfactory in service. 3.16.3.2All parts of the sleeve joint shall be either inherently resistant to atmospheric corrosion, both

during storage and in service. 3.16.3.3The sleeve joint shall be suitable for use on aluminium conductor steel-reinforced of outer

diameter in the range of 7.00 mm to 18.2 mm. (25 sq. mm and 150 sq. mm). 3.16.3.4The sleeve joint shall have an ultimate strength of at least 95% of the conductor and an

electrical conductivity equal to that of the conductor such that it can be used in mid-span.

3.16.4 MARKING

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1 Each fitting shall be stamped with the type number and metric conductor size with which it is to be used.

3.16.5 TESTS

All fittings in this specification shall, when applied to the appropriate conductor, comply with the requirements of this specification.

The fittings shall be tested as per the requirement of this specification.

3.17 GALVANISED STEELWORKS FOR OVERHEAD LINES. 3.17.1 SCOPE 3.17.2 This specification is for galvanised mild steelworks for overhead lines and pole mounted transformers. 3.17.3 This specification is for the following steelworks.

(i) steel cross arms of different configurations for use on wood poles. (ii) supporting steelworks for ancillary equipment. (iii) steelworks for supporting and terminating HV and MV/LV overhead lines and services.

3.17.2 REFERENCES The following documents were referred to during the preparation of this specification and unless

specified, the latest revision, edition and amendments shall apply. In case of conflict, the provision of this specification shall take precedence.

BS 4 Structural steel sections

BS 729 Specification for hot dip galvanised coating on iron and steel articles

BS 4360 Specification for weldable structural steel

BS 5135 Specification for arc welding of carbon and carbon manganese steels

ESI 43 - 95 Steelworks for overhead lines

3.17.3 TERMS AND DEFINITIONS For the purpose of this specification, the definitions in the reference standards shall apply. 3.17.4 SERVICE CONDITIONS See clause 1.5 3.17.5 MATERIALS

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4.2.1. Structural steel used, shall be grade 43A as specified in the BS 4360: 1972 “Specification for weldeable structural steel”.

The tensile strength and yield stress of the steel shall be not less than 430/510 N/sq. mm and 255

N/sq. mm respectively. Angle sections shall be as per BS 4848 Channel sections shall be as per BS 4 4.2.2. Welding

Welding where specified, shall be by metal-arc welding and shall be as per BS 5135:1974 After welding and before galvanising, welds shall be thoroughly cleared to remove slag and spatter,

preferably by sand blasting. 3.17.6 CONSTRUCTION - FABRICATION 3.17.6.1All materials before and after fabrication shall be straight and free from twists. 3.17.6.2All dimensions specified shall be subject to the following tolerances, unless stated.

(i) Dimensions up to and including 0 mm - (1 mm)

(ii) Dimensions greater than 50 mm - (2 mm).

3.17.6.3 Erection clearance for cleated ends of members connecting steel to steel shall not be greater than 2mm at each end.

3.17.6.4 Bolt holes shall not be more than 2mm greater than the diameter of the bolt for bolts up to 24mm diameter.

3.17.6.5 Cutting may be by shearing, cropping, sawing or machine flare cutting. Sheared or cropped edge shall be dressed to a neat finish and be free from distortion where parts are to be in metal contact.

3.17.6.6 All holes shall be drilled in one operation and burrs shall be removed. Holes shall not be formed by a gas cutting process. All matching holes for bolts shall register with each other so that a gauge 2mm less in diameter than the diameter of the bolt shall pass freely through the assembled members in a direction at right angle to such members.

3.17.6.7 All components shall be thoroughly galvanised by hot dip method after fabrication and shall comply with the requirement of BS 729:1991.

3.17.6.8 Bending of flat straps shall be carried out cold. 3.17.7 TESTS

a. The tensile strength, yield strength, elongation and bending tests shall be done in accordance with the requirement of BS 4360.

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b. Tests on galvanising shall be carried on the finished steel in accordance with the requirement of BS 729.

3.17.8 PACKING

Each assembly and package of items associated with this specification shall be suitably marked with reference to KPLC code. Where an item includes a number of components to form a complete assembly, all component parts shall be included in one composite package, which shall be firmly strapped or bound together.

LIST OF STEELWORKS

ITEM KPLC CODE

FUNCTION

181201 D - Iron (LV Insulator Bracket) 188104 Shackle strap 188115 11 kV tie strap (flat) 188111 11 kV tie strap (angle) 188108 33 kV tie strap 188107 11 kV terminal strap 188109 33 kV terminal strap Earth stock 182911 11kV steel cross arm (1620 X 70 X 70) 186914 11 kV steel cross arm – Terminal (1620 X 125 X 76) 186914 33 kV steel cross arm – Terminal (2400 X 100 X 75) 186925 Fuse/Taplin Isolator cross member (2290 X 100 X 50)

(Channel for all transformers - 4” X 2” X 1/4”)

186921 Steady Insulator cross member (2290 X 100 X 50) (Channel for up to 200 kVA - 4” X 2” X 1/4”)

186922 Steady Insulator cross member (2290 X 125 X 64) (Channel for 300 kVA - 5” X 2 1/2” X 1/4”)

186923 Transformer Platform (4” X 2” X 1/4”)

(Up to 200 kVA)

186924 Transformer Platform (5” X 2 1/2 X 1/4”) 186924 Transformer Mounting Bracket (2 1/2” X 2 1/2” X 1/4”)

(For transformer platform - Code 86924)

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3.18 EARTHING 3.18.0 SPECIFICATION FOR EARTH RODS 3.18.1 SCOPE

This specification is for extensible earth rods and non-extensible earth rods with associated connectors.

3.18.2 SERVICE CONDITIONS See clause 1.5 3.18.3 MATERIAL AND CONSTRUCTION

a. Steel for rods shall be low carbon high tensile steel complying with BS 4360 grade 43A.

b. The steel shall be clad with copper to a minimum thickness of 0.35mm which shall be molecularly bonded to the steel.

c. The rod shall be capable of being bent through 90° at a maximum radius of 100mm with no copper fracture and with no ill effect on the bond between the steel and the copper cladding.

d. The threading shall be unified coarse (UNC) and shall be formed by rolling after application of the copper clad.

e. The coupling shall be phosphor bronze complying with BS 2874. f. The connector shall be electrolytic tough pitch high conductivity copper,

complying with the requirement of BS 1977. 3.18.4 STANDARD SIZES

The standard sizes of the earth rods shall be as follows:- KPLC CODE ROD LENGTH ROD DIAMETER

186539

(ft) (m)* (in) (mm)*

12 3.6 7/8 22.0

186544 5 1.5 ½ 12.5

186545 7 2.1 5/8 16.0

186555 4 1.2 ½ 12.5 * Metric values are approximated.

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3.18.5 TESTS

Tests shall be done as per the requirement of this specification. 3.18.6 REFERENCES

The following documents were referred to during the preparation of this specification.

They may be used as references, in case of conflict, the provision of this specification shall take precedence. Unless otherwise specified, the latest revision, edition and amendments shall apply. BS 4360 - Specification for weldable structural steel. BS 2874 - Copper and copper alloys. Rods and sections. BS 1977 - Specification Copper for Electrical Purposes. ESI 43-94 - Earth rods and their connectors.

3.18.7 EARTHING CONDUCTORS 3.18.7.1 SCOPE

This specification covers the design, manufacture testing and supply of copper conductors for earthing power distribution and transmission system. This specification covers the following conductor sizes. 50 Sq. mm stranded copper conductor, PVC covered. 70 Sq. mm stranded copper conductor, PVC covered . 100 Sq. mm stranded copper conductor, PVC covered.

3.18.7.2 REFERENCES

The equipment shall comply with the latest edition and amendments of the Standards listed herein. BS 125: Hard – drawn copper and copper – cadmium conductors for overhead power

transmission purposes. BS 6485: PVC – covered conductors for overhead power lines. BS 6746: PVC insulation and sheath of electric cables. BS 4109: Specification for copper for electrical purposes. Wire for general electrical

purposes and for insulated cables and flexible cords.

3.18.7.3 MATERIALS

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(a) Copper wires used shall be high conductivity hard drawn copper wires.

The wires shall be clean, smooth and free from harmful defects.

(b) The conductor cover shall be black polyvinyl chloride (PVC) compound Type TII according to BS 6746 and shall be applied by extrusion.

(c) The insulation shall have a thickness of not less than 0.8 mm and the covered conductor shall comply with the requirement of BS 6485.

3.18.7.4 CONSTRUCTION (a) The conductor shall be manufactured as per BS 6485. (b) The conductor shall be concentrically stranded, with successive layers in opposite direction

of lay, but such that the outer layer shall be in the right hand spiral. The wires in each layer shall be evenly and closely stranded.

3.18.7.5 STANDARD SIZES

The Standard Sizes for copper conductors shall be as follows:-

CONDUCTOR Nominal Area of Copper (mm²) 50 70 100 Approximate overall diameter of uncovered conductor(mm).

9.00 10.65 12.9

Approximate overall diameter of covered conductor (mm).

11.9 13.5 15.7

Stranding No/mm 7/3.00 7/3.55 7/4.30 Calculated maximum d.c. resistance at 20°C (� /Km)

0.1804

Breaking load (N) 19497 26880 37640 3.18.7.6 TESTS

The conductors shall be inspected and routine tested in accordance with the requirements of BS 6485 and BS 125.

3.18.7.7 PACKING

The complete conductor shall be rolled on wooden drums such as to prevent damage during transportation. The wooden drums shall be made from treated timber resistant to termite attack. The following description shall be marked on one flange of the reel Direction of rotation of the reel

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Type of conductor and size Length

Manufacturer’s name Year of manufacture

3.19 SPECIFICATION FOR 11kV EXPULSION FUSE LINKS- 3.19.1 SCOPE This standard specifies requirements for expulsion fuse links to be used outdoors on 11kV, 50Hz ac system for protection and isolation of substation apparatus and sectionalising purposes. This specification covers the following sizes of fuse links:

i) 5A Expulsion Fuse Links ii) 10A Expulsion Fuse Links iii) 15A Expulsion Fuse Links

iv) 25A Expulsion Fuse Links

v) 40A Expulsion Fuse Links

vi) 65A Expulsion Fuse Links

3.19.2 SERVICE CONDITIONS See clause 1.5

3.19.3 DESIGN AND CONSTRUCTION

3.19.3.1 The fuse link shall be buttonhead single tail type designed and constructed as per the requirement of IEC60282-2.

3.19.3.2 The fuse link shall be suitable for use in distribution fuse cut out, drop out type. 3.19.3.3 It shall be high-speed designated type K in accordance with IEC 60282-2. 3.19.3.4 The minimum overall length of the expulsion fuse link to be used on 11kV system

shall be 51 cm.

3.19.4 RATING The fuse links shall be of the following ratings:

Rated Voltage 12kV Rated Current Various (5A, 10A,15A,

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25A, 40A and 65A) Rate Frequency 50Hz

3.19.5 MARKING AND INFORMATION

Technical details including time/current characteristics for the fuse links being offered shall be submitted for evaluation. The following information shall be marked indelibly and legibly on the fuse link:

iii) Manufacturers name or trademark iv) Manufacturers type designation v) Rated current and speed designation vi) Rated voltage The marking shall be on the button head as well as on the tube surrounding the fuse element.

3.19.6 TESTS

Type Tests for the expulsion fuse links shall be in accordance with IEC60282-2.

3.19.7 REFERENCES The following documents were referred to during the preparation of this specification; in case of conflict, the provision of this specification shall take precedence. IEC 60282 –2 : High Voltage Fuses, Part 2 : Expulsion Fuses

3.20 SPECIFICATION FOR 11KV EXPULSION FUSE CUT-OUT 3.20.1 SCOPE

a. This specification is for 11 kV Expulsion Fuse Cut-out for use in protection and isolation of substation apparatus and sectionalising purposes.

b. The Expulsion Fuse Cut-out incorporates the fuse mount (fuse base) and its fuse-carrier

3.20.2 SERVICE CONDITIONS

See clause 1.5

3.20.3 DESIGN AND CONSTRUCTION

a) General

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3.20.3.1.1 The Expulsion Fuse Cut-out shall be designed and manufactured in accordance with IEC 282 part 2.

3.20.3.1.2 The Expulsion Fuse Cut-out shall be supplied as a complete unit incorporating the fuse mount (fuse base) with its fuse-carrier.

3.20.3.1.3 All current carrying parts shall be of electrolytic high conductivity copper with the contacts hard drawn copper and silver-plated.

b) Fuse mount (fuse base)

3.20.3.1.4 The fuse mount shall incorporate Porcelain or Silicon Rubber insulators to suit voltage

insulation requirements and a hot dip galvanized steel bracket suitable for angle mounting on a steel channel. The fuse cut-out shall be secured on the mounting bracket by a minimum of two bolts complete with nuts.

3.20.3.1.5 The fuse base shall be complete with contacts, terminals for connection to the external circuit and accessories all suitable for the specified atmospheric conditions.

3.20.3.2 The hinge shall be in cast bronze. 3.20.3.2.1 The terminals shall be suitable for both copper and aluminium conductors of diameter

sizes up to 18.2mm. The nut for securing the fuse (tail end) shall be in stainless steel. 3.20.3.2.2 The fuse mount shall be arranged such that each unit is mounted independently on an

angle bracket.

c) Fuse Carrier 3.20.3.2.3 The fuse carrier shall be of the vertical opening, single pole operation and suitable for

manual removal from and insertion into the fuse mount from ground level with the aid of insulated operating rod fitted with expulsion fuse head.

3.20.3.2.4 The fuse carrier shall be suitable for use as drop out expulsion fuse isolator. The fuse carrier shall be designed and manufactured to accommodate standard expulsion fuse link of the button head single tail type.

3.20.3.2.5 The lower and upper tubes as well as the pull ring (eye) of the fuse carrier shall all be in cast bronze.

3.20.3.2.6 The fuse carrier shall be spring loaded at the lower end to ensure an even tension on the fuse link and adequate contact pressure to assist in expelling the fuse carrier when the fuse blows.

3.20.3.2.7 The fuse carrier shall be designed such that it is removable from the fuse mount and when removed, shall provide adequate electrical isolation between the contact points.

3.20.4 RATING

The rating of the complete fuse cut-out shall be as follows: - Rated voltage 12 kV Rated lightning impulse withstand voltage 95 kV Rated 1min. power frequency withstand voltage (wet) 45 kV Rated frequency 50 Hz Rated breaking capacity 8 kA Rated short circuit current withstand of fuse base & carrier 12.5 kA (3sec) Rated current of fuse base 200A Minimum creepage distance 320 mm

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3.20.5 TEST 3.20.5.1.1 The fuse cut-out shall be inspected and tested in accordance with the requirement of IEC

282 –2 and this specification. 3.20.5.1.2 Certified type test certificates issued by the relevant National Testing Authority

confirming compliance of the fuse cut-out offered with the requirement shall be submitted.

3.20.5.1.3 The tenderer shall submit a detailed clause by clause statement of compliance with these specifications for evaluation. Detailed manufacturer’s catalogues, drawings and manuals/brochures clearly marked and showing the offered equipment item and type reference numbers MUST be submitted for evaluation.

3.20.5.1.4 The manufacturer’s certified Declaration of Conformity to reference standards, ISO Quality Assurance Certification and detailed list of previous customers (utilities) outside the country of manufacture shall also be submitted.

3.20.6 REFERENCES The following documents were referred to during the preparation of this specification, and may be

referred to; in case of conflict the provision of this specification shall take precedence. Unless otherwise specified, the latest revision, edition and amendments shall apply. IEC 282: High – Voltage fuses Part 2: Expulsion and similar fuses BS 729: Hot dips galvanized coating on iron and steel articles. 3.21 SPECIFICATION FOR 33 KV EXPULSION FUSE CUT-OUT 3.21.1 SCOPE

This specification is for 33 kV Expulsion Fuse cut-Out for use in protection and isolation of substation apparatus and sectionalising purposes.

3.21.2 SERVICE CONDITIONS

see clause 1.5

3.21.3 CONSTRUCTION 3.21.3.1 The fuse mount shall incorporate porcelain insulators to suit voltage requirements and

removable drop out expulsion fuse link carrier, suitable for fuse links of the button head single tail type.

The fuse cut-out shall be mounted on a hot dipped galvanised steel bracket suitable for vertical mounting.

Galvanising shall be as per the requirement of BS 729.

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3.21.3.2 The fuse carrier shall be of the vertical opening, single pole operation and suitable for manual removal from and insertion into the fuse mount from ground level with the aid of an insulated operating stick.

3.21.3.3 The fuse mount shall be arranged such that each unit is mounted on an angle bracket or channel base mounting.

3.21.3.4 The fuse carrier shall be spring loaded at the lower end to ensure an even tension on the fuse link and adequate contact pressure to assist in expelling the link tail from the carrier when fuse blows.

3.21.3.5 The fuse carrier shall be designed such that it is removable from the fuse mount and when removed, shall provide adequate electrical isolation between the contact points.

3.21.3.6 All current carrying parts shall be of electrolytic high conductivity material. 3.21.4 RATING

The rating of the fuse cut-out assembly shall be as follows:- Rated voltage 36 kV Rated lightning impulse withstand voltage 170 kV Rated power frequency withstand voltage (wet) 70 kV Rated frequency 50 Hz Rated short time withstand current for 3 seconds 25 kA Minimum creepage distance 1000 mm

3.21.5 TEST The fuse mount shall be inspected and tested in accordance with the requirement of this specification. 3.22 SPECIFICATION FOR 33 KV EXPULSION FUSE HOLDER 3.22.1 SCOPE

This specification is for 33 kV drop out expulsion fuse holder for use on line disconnection, isolation of substation apparatus and sectionalising purposes.

3.22.2 SERVICE CONDITIONS See clause 1.5 3.22.3 CONSTRUCTION 3.22.3.1.1 The fuse holder (carrier) shall be of the vertical opening, single pole operation and

suitable for manual removal from and in section into the fuse mount from ground level with the aid of insulated operating stick.

3.22.3.1.2 The fuse holder shall be suitable for use on drop out expulsion fuse isolator. The fuse holder shall be designed and manufactured to accommodate standard expulsion fuse link of the button head single tail type.

3.22.3.1.3 The fuse holder shall be spring loaded at the lower end to ensure an even tension on the fuse link and adequate contact pressure to assist in expelling the link tail from the holder when fuse blows.

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3.22.3.1.4 The fuse holder shall be designed such that it is removable from the fuse mount and when removed, shall provide adequate electrical isolation between the contact points.

3.22.3.1.5 All current carrying parts shall be of electrolytic high conductivity material with the contacts hard drawn and silver plated.

3.22.4 RATING

The rating of the fuse holder shall be as follows:- Rated voltage 36 kV Rated lightening impulse withstand voltage 170 kV Rated power frequency withstand voltage (wet) 95 kV Rated frequency 50 Hz Rated short time withstand current for 3 seconds 12.5 kA Minimum creepage distance 1000 mm Length 482.6 mm (19”)

3.22.5 TESTS

The fuse holder shall be inspected and tested in accordance with the requirement of this specification.

3.23 SPECIFICATION FOR LOW VOLTAGE CARTRIDGE FUSES 3.23.1 SCOPE 1.1. This specification is for Low Voltage cartridge fuses for use in a.c. electricity supply

network. 1.2. This specification is for the following cartridge fuse links

(i) Fuse links for use in consumer input terminals in domestic and similar premises

(ii) Fuse links for use in transformer take – off Particular requirement for each fuse link is given in section 4.3 3.23.2 REFERENCES

The following documents were referred to during the preparation of this specification. In case of conflict, the provision of this specification shall take precedence.

IEC 269: Low - voltage fuses BS 88: Cartridge fuses for voltages up to and including 1000 V a.c. and 1500 V d.c. BS 1361: Cartridge fuses for a.c. circuits in domestic and similar premises.

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3.23.3 TERMS AND DEFINITIONS

For the purpose of this specification, the definitions in the reference standard shall apply. 3.23.4 SERVICE CONDITIONS

See clause 1.5 3.23.5 CONSTRUCTION 3.23.5.1 The fuse shall be High Rupturing Capacity (HRC) type and constructed as per the

requirement of IEC 269, BS 1361 and BS 88. 3.23.5.1 The fuse shall be suitable for use on distribution transformer take - off, distribution

panels, feeder pillars and domestic installation. 3.23.5.1 The non - extinguishing medium used shall be of quality to ensure proper operations

under service duty of the fuse. 3.23.6 PARTICULAR REQUIREMENTS a Fuses for domestic and similar premises take – off 3.23.6.1 The fuse shall be barrel type with end caps for cylindrical contacts for insertion in a

fuse carrier.

The end caps shall be suitably protected against corrosion.

3.23.6.2 The fuse link shall have a length of 57mm and end cap diameter of 22.23mm as specified in BS 1361 for type IIa fuse link.

b Fuses for transformer take – off 3.23.6.3 The fuse shall be slotted tag pattern with wedge type contacts for insertion in a fuse

carrier. 3.23.7 RATING The rating of the fuses shall be as follows:-

(i) Fuses for domestic and similar premises

Rated voltage Volts 240 415 Rated current Amps 30 60 Maximum power loss Watts 3.0 5.5 Minimum breaking capacity kA 16.5 33

(ii) Fuses for transformer take - off

Rated voltage Volts 415 415 415 415 415 415 Rated current Amps 63 100 160 200 315 400

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Maximum power dissipation Watts 6 10 14 18 29 33 Minimum breaking capacity kA 46 46 46 46 46 46

Time/current zones shall be as indicated in BS 88 Part 5 and BS 1361. 3.23.8 TESTS

The fuse shall be inspected and tested in accordance with the requirement of BS 88 Parts 1 and 5 and BS 1361. Type test certificates for each type of fuse shall be submitted for approval before shipment.

3.24 SPECIFICATION FOR LOW VOLTAGE FUSE CUT-OUT 3.24.1 SCOPE 1.1. This specification is for indoor low voltage fuse cut – out intended for use at distribution

transformer take – off and consumer input terminals. 1.2. This specification is for the following fuse cut – outs

(i) Overhead service cut out (Transformer fuse cut out) (ii) Underground service cut out (iii) House service cut out

Particular requirements for each cut out fuse type are given in section 4

3.24.2 REFERENCES

The following documents were referred to during the preparation of this specification, and may be referred to in case of conflict, the provision of this specification shall take precedence.

Unless otherwise specified, the latest revision, edition and amendments shall apply.

IEC 269: Low – voltage fuses BS 88: Cartridge fuses for voltages up to and including 1000V a.c. and 1500V d.c. BS 1361: Cartridge fuses for a.c. circuits in domestic and similar premises

3.24.3 SERVICE CONDITIONS

See clause 1.5

3.24.4 CONSTRUCTION 3.24.4.1 The fuse base shall be manufactured from moulded phenolic, glazed porcelain or

reinforced fibre glass material, suitable for mounting in a steel cubicle.

The fuse carrier shall be manufactured from the same material as the fuse base.

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3.24.4.2 The fuse base and the fuse carrier shall interlock fully when fitted to provide weather proof housing and all live parts fully shielded.

3.24.5 PARTICULAR REQUIREMENTS 1 House Service cut out 3.24.5.1 The House Service cut out shall be suitable for terminating both aluminium and

copper cables preferably by at least two pinching screws of adequate size and strength and shall be of the following types.

(a) Single pole insulated House Service cut out without neutral link or earthing block (b) Single pole insulated House Service cut out with neutral link

3.24.5.2 The fuse base shall be fitted with conductor terminals to suit stranded aluminium and copper conductors of up to 35 sq. mm nominal area.

3.24.5.3 The fuse carrier shall be suitable for barrel fuse link type IIa as specified in BS 1361

Provision shall be made for sealing the fuse carrier to the fuse base when fitted.

2 Underground service cut out 3.24.5.4 The Underground Service cut out shall be suitable for terminating aluminium cables

preferably by at least two pinching screws of adequate size and strength. 3.24.5.5 The fuse base shall be fitted with conductor terminals to suit stranded aluminium

conductors of up to 300 sq. mm nominal area. 3.24.5.6 The fuse base shall be suitable for wedge type fuses of 83mm fixing centres as per

BS88.

The fuse base for neutral phase shall be similar to fuse base of other phases. 3.24.5.7 The fuse base for neutral phase shall be similar to fuse base of other phases. 3.24.5.8 The fuse carrier shall be fitted with wedge type thumb screw operated contacts for

83mm centre HRC fuse link

The fuse carrier for the neutral phase shall be fitted with distinctive NEUTRAL cover and fitted with solid link

3 Overhead service cut out 3.24.5.9 The Overhead ground Service cut out shall be suitable for terminating aluminium and

copper cables. 3.24.5.10 The fuse base shall be suitable for outdoor mounting on a wood cross arm and shall be

fitted with conductor terminals to suit stranded aluminium conductors of up to 300 sq. mm nominal area.

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3.24.5.11 The fuse base shall be suitable for wedge type fuses of 83mm fixing centres as per BS88.

3.24.5.12 The fuse carrier shall be fitted with wedge type thumb screw operated contacts for 83mm centre HRC fuse link

3.24.6 RATING

The rating of the fuse cut-out assembly shall be as follows:-

a House service cut out

Rated voltage 415 Volts Rated current 60/80 A

b Overhead and Underground service cut outs

Rated voltage 415 Volts Rated current: Overhead service cut out Underground service cut out

400 A 300 A

Rated frequency

3.24.7 TEST

The fuse shall be inspected and tested in accordance with the requirement of BS 88 Parts 1 and 5 and BS 1361. Type test certificates for each type of fuse shall be submitted for approval before shipment.

APPENDIX LOW VOLTAGE FUSE CUT OUT KPLC CODE DESCRIPTION 116236 80 Amps LV Single cut out 116237 80 Amps LV Double cut out 116247 Cut out for 70 –185 sq. mm LV cable 183203 400 Amps LV Transformer cut out

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3.25 LOW VOLTAGE AERIAL BUNDLED CABLES (SELF SUPPORTING TYPE) 3.25.1 SCOPE 3.25.2 1.1 This specification is for four core, aerial bundled cable, insulated with , cross-linked

polyethylene (XLPE) rated at 600/1000 volts, intended for use on overhead low voltage electricity distribution lines. When specifically requested, the bundle may contain additional cores for street lighting or for pilot signals. The cable is intended to be supported by a strain-bearing neutral conductor.

1.2 This specification is for the following bundle sizes; all conductors to be XLPE insulated:-

3 x 35 sq. mm Aluminium phase conductors with 54.6 sq. mm Aluminium alloy neutral conductor.

3 x 70 sq. mm Aluminium phase conductors with 54.6 sq. mm Aluminium alloy neutral conductor.

3 x 120 sq. mm Aluminium phase conductors with 70 sq. mm Aluminium alloy neutral conductor.

3.25.3 SERVICE CONDITIONS Clasue 1.5 3.25.4 MATERIAL AND CONSTRUCTION 3.25.4.1 The conductor shall be made from hard drawn, circular, stranded and compacted

plain aluminium conductor as per IEC 228. 3.25.4.2 The conductor shall be stranded with successive concentric layers on opposite lay.

The outer layer in all the stranded conductors shall have right hand lay (Z). 3.25.4.3 The neutral conductor shall be stranded compacted aluminium alloy with

tensile strength not less than 294 N/sq. mm. 3.25.4.4 The insulation shall be black, weather resistant, ultra-violet radiation protected cross-

linked polyethylene (XLPE). 3.25.4.5 The neutral core shall be indicated by one continuous rib on its insulation

jacket throughout its length. The rib shall not be less than 0.5mm in height. 3.25.4.6 Each of the phase cores shall be permanently marked throughout its length, preferably

by embossment or indenting on the insulation, for identification. The markings shall consist of upright block alfa-numeric characters of minimum size not less than 15% of the average overall core diameter.

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3.25.5 STANDARD SIZES AND CHARACTERISTICS The standard sizes and characteristics of the aerial overhead cables shall be as follows:- Parameter Unit Aerial Bundled Conductor ( cores sizes in

mm2 ) 1x54.6 + 3x35 1x54.6 + 3x70 1x70 + 3x120 Nominal area of phase

conductor mm2 35 70 120

Nominal area of neutral conductor

mm2 54.6 54.6 70

DC resistance of phase conductor at 20C

/km 0.868 0.443 0.253

DC resistance of neutral conductor at 20C

/km 0.63 0.63 0.50

Min. Insulation thickness

mm 1.6 1.6 1.7

Min. tensile strength of neutral conductor

kN 16.6 16.6 20.6

3.25.6 TESTS

The finished cable shall be tested in accordance with the requirements of clauses 1 , 2 and 3 of this specification, otherwise as per the requirements of IEC 228 and NFC 33 - 209, as applicable.

1 Routine Tests Conductor resistance

The d.c resistance of each phase conductor and of the neutral conductor shall be measured together with the temperature of the cable at the time of measurement in accordance with IEC 228.

The result when corrected to 20C shall not exceed the maximum values given in table 4.1.

Dimensions

The measurement of dimensions of the cable components as specified in table 4.1 shall be made on three test pieces taken at 3 points, at least 1m apart from the core under test.

The measurement shall be done in accordance with French National Standard, NFC 33-209 (1988), sub-clause 3.2.1.

Dielectric Strength of Cores

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Each completed drum length of ABC shall be immersed in a waterbath and be subjected to an overvoltage test in accordance with NFC 33-209 Appendix VII.2 The ABC shall withstand, without breakdown of the insulation, an ac power frequency voltage of RMS value 4kV between the conductors and the waterbath.

2 Batch Tests Verification of adhesion of the insulation to the conductor of messenger neutral

When a supporting neutral core is tested in accordance with clause 5.5. of NFC 33-209 (1988) the force Fs required to initiate sliding of the dielectric over the conductor shall be at least 180N.

. Measurement of Insulation Resistance

Insulation resistance to comply with NFC 33-209 (1988) clause 5.3. 3 Type Tests Mechanical Strength

The mechanical strength shall be determined in accordance with the requirements of NFC 33-209 (1988) clause 5.1.

Weather Resistance

The weather resistance shall be determined in accordance with the requirement of NFC 33-209 (1988) clause 5.2.

Performance of Supporting Cores

The stability of the messenger neutral under thermal and mechanical loading shall be verified in accordance with NFC 33-209 (1988) clause 5.8.

Behaviour Under Impulse Voltages

Compliance with NFC 33-209 (1988) clause 5.7.

3.26 SINGLE CORE LV ALUMINIUM CABLE (PVC). 3.26.1 SCOPE 3.26.2 1.1. This specification is for single core, stranded aluminium conductors, polyvinyl chloride

(PVC) insulated, armoured, PVC outer sheathed power cables for operation upto and including 600 volts to sheath and 1000 volts between conductors.

1.2. This specification is for following cable sizes:-

630 sq. mm Aluminium conductor PVC insulated single core cable

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300 sq. mm Aluminium conductor PVC insulated single core cable 16 sq. mm Aluminium conductor PVC insulated single core cable

25 sq. mm Aluminium conductor PVC insulated single core cable

35 sq. mm Aluminium conductor PVC insulated single core cable

3.26.3 REFERENCES

The following documents were referred to during the preparation of this specification. In cases of conflict, the provisions of this specification shall take precedence.

Unless otherwise specified, the latest revision, edition and amendments shall apply.

IEC 228(1978):- Conductors of insulated cables

IEC 502:(1983):- Extruded solid dielectric insulated power cables for rated voltages from 1

kV upto 30 kV

IEC 811:- Common test methods for insulating and sheathing materials of electric cables

BS 6346(1969):- PVC - insulated cables for Electricity supply (with 1974 ammendments). 3.26.4 SERVICE CONDITIONS

See clause 1.5 3.26.5 MATERIAL AND CONSTRUCTION 3.26.5.1 The cable in general shall be designed and manufactured according to the requirement of

IEC 227, IEC228 and BS 6346. 3.26.5.2 The phase conductors of the cable shall be made from circular stranded compact plain

aluminium conductor as per IEC 228. 3.26.5.3 The insulation shall be polyvinyl chloride (PVC) complying with the requirement of IEC

502 for type PVC/A and shall be suitable for climatic conditions described. 3.26.5.4 The insulation shall be applied by extrusion process and shall form a compact

homogeneous body. 3.26.5.5 The insulation shall concentrically cover the conductor. 3.26.5.6 Where necessary, the cable shall be cored with suitable non-hydroscopic inner covering

and filler to make a substantially circular cable. 3.26.5.7 Extruded oversheath shall be of black polyvinyl chloride (PVC). 3.26.5.8 The cable shall be clearly and permanently embossed with the following information

throughout the length of the oversheath. Letters and figures, raised and consist of upright block characters. Minimum size of characters not less than 15% of average overall cable diameter.

(i) 600/1000 VOLTS PVC CABLE PROPERTY OF KPLC.

(ii) Year of manufacture.

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(iii) Size of cable

(Example: ‘630 SQ MM 600/1000 VOLTS PVC CABLE PROPERTY OF KPLC 2000’)

3.26.6 STANDARD SIZES AND CHARACTERISTICS The characteristics of the cables shall comply with the following table

Item Characteristics Conductor resistance Not more than the value

indicated A.C. withstand voltage To withstand the indicated

value for 5 min. Insulation resistance Not less than the value

indicated. Tensil strength and elongation

PVC Tensil strength, minimum

12.5N/mm (1.27 Kg/mm)

Aging requirement*

PVC Elongation , minimum percentage of unaged value

150% 75 - 125%

* Properties after Ageing in air oven:

temperature 100 2°C duration of treatment 168 hrs

The standard sizes for the PVC cables shall be as follows:-

Cable size 630 sq. mm

300 sq. mm

16 25 35

Nominal sectional area

630 sq. mm

300 sq. mm

16 25 35

Thickness of insulation

2.8 mm 2.4 mm 1.0 1.2 1.2

Thickness of outer sheath

2.2 mm 2.2 mm 1.4 1.4 1.4

Nominal overall diameter

38.8mm 28.0 mm 10.2 18.0 14.4

Approximate net weight

6200 kg/km

3100 kg/km

230 350 450

Test voltage 3kV/5min 3kV/5min 3 3 3 Maximum conductive resistance ohms/km

0.007 0.0120 1860 1970 (N)

1180 1240

851 900

Minimum insulation resistance

5 5 5 5 5

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3.26.7 TESTS

The cable cores, sheath and completed cable shall be tested in accordance with the requirements of IEC 811 and BS 6346. Test certificates shall be certified by the National Testing or the National Standards Institute of the country of origin. Sample copies for similar material shall be presented with the tender for the purpose of technical evaluation.

3.27 SINGLE CORE LV COPPER CABLE (PVC) 3.27.1 SCOPE 1.1 This specification is for single core, stranded copper conductors, polyvinyl chloride (PVC)

insulated, combined neutral/earth, PVC outer sheathed service cables for operation upto and including 600 volts to sheath and 1000 Volts between conductors.

1.2 This specification is for the following cable sizes:-

10 sq. mm copper conductor PVC insulated single core cable 16 sq. mm copper conductor PVC insulated single core cable 25 sq. mm copper conductor PVC insulated single core cable

3.27.2 MATERIAL AND CONSTRUCTION 3.27.2.1.1 The cable in general shall be designed and manufactured according to the requirement of

IEC 227, IEC228 and BS 6346. 3.27.2.1.2 The phase conductor of the cable shall be made from circular stranded compact plain

annealed copper conductor as per IEC 228. 3.27.2.1.3 The combined neutral/earth conductor shall be made from plain annealed copper wires as

per BS 4109. The concentric layer shall be applied helically with a right hand direction of lay. The maximum gap between adjacent wires shall not exceed 4mm.

3.27.2.1.4 The insulation shall be polyvinyl chloride (PVC) complying with the requirement of IEC 502 for type PVC/A and shall be suitable for the climatic conditions described. The insulation of the phase conductor shall be coloured red.

3.27.2.1.5 The insulation shall be applied by extrusion process and shall form a compact homogeneous body. The insulation shall concentrically cover the conductor.

3.27.2.1.6 Extruded oversheath shall be of black polyvinyl chloride (PVC). 3.27.3 STANDARD SIZES AND CHARACTERISTICS The characteristics of the cables shall comply with the following table

Item Characteristics Conductor resistance Not more than the value

indicated A.C. withstand voltage To withstand the indicated

value for 5 min. Insulation resistance Not less than the value

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indicated. Tensil strength and elongation

PVC Tensil strength, minimum

12.5N/mm (1.27 Kg/mm)

Aging requirement*

PVC Elongation , minimum percentage of unaged value

150% 75 - 125%

* Properties after Ageing in air oven:

temperature 100 2°C duration of treatment 168 hrs

The standard sizes for the PVC cables shall be as follows:- Conductor nominal sectional area sq. mm 10 16 25 Conductor shape compact round stranded Thickness of insulation mm 1.0 1.0 1.2 Diameter of concentric neutral wire mm 0.66 0.85 1.13 Thickness of outer sheath mm 1.4 1.4 1.4 Approximate overall diameter mm 12.1 14.4 Approximate weight kg/km 270 450 650 Test Voltage kV/5 min 3 3 3 Maximum resistance at 200C: conductor neutral

/m /m

1800 1920

1130 1200

712 750

Minimum insulation resistance at 200C M-km 5 5 5

3.28 FOUR CORE LV ALUMINIUM CABLE (PVC). 3.28.1 SCOPE 3.28.2 1.1. This specification is for four core, stranded aluminium conductors, polyvinyl chloride (PVC)

insulated, single wire armoured, PVC outer sheathed power cables for operation upto and including 600 volts to earth and 1000 volts between conductors.

1.2. This specification is for the following cable sizes:-

25 sq mm Aluminium conductor PVC insulated four core cable

70 sq mm Aluminium conductor PVC insulated four core cable

120 sq mm Aluminium conductor PVC insulated four core cable

185 sq mm Aluminium conductor PVC insulated four core cable

300 sq mm Aluminium conductor PVC insulated four core cable

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3.28.3 MATERIAL AND CONSTRUCTION 3.28.3.1 The cable in general shall be designed and manufactured according to the requirement

of IEC 227, IEC228 and BS 6346. 3.28.3.2 The phase conductors of the cable shall be made from circular stranded compact plain

aluminium conductor as per IEC 228. 3.28.3.3 The insulation shall be polyvinyl chloride (PVC) complying with the requirement of

IEC 502 for type PVC/A and shall be suitable for climatic conditions described. 3.28.3.4 The insulation shall be applied by extrusion process and shall form a compact

homogeneous body. 3.28.3.5 The insulation shall concentrically cover the conductor. 3.28.3.6 Where necessary, the cable shall be cored with suitable non-hydroscopic inner

covering and filler to make a substantially circular cable. 3.28.3.7 Extruded oversheath shall be of black polyvinyl chloride (PVC). 3.28.3.8 The individual cores shall be identified by coloured insulation and the colour shall be

red, yellow, blue and black. 3.28.4 STANDARD SIZES AND CHARACTERISTICS The characteristics of the cables shall comply with the following table

Item Characteristics Conductor resistance Not more than the value

indicated A.C. withstand voltage To withstand the indicated

value for 5 min. Insulation resistance Not less than the value

indicated. Tensil strength and elongation

PVC Tensil strength, minimum

12.5N/mm (1.27 Kg/mm)

Aging requirement*

PVC Elongation , minimum percentage of unaged value

150% 75 - 125%

* Properties after Ageing in air oven:

temperature 100 2°C duration of treatment 168 hrsThe standard sizes for the PVC

cables shall be as follows:-

Conductor nominal sectional area sq. mm 25 70 120 185 300 Conductor shape compact round stranded Conductor diameter mm 8.5 11.5 13.2 16.4 20.8 Thickness of insulation mm 1.2 1.4 1.6 2.0 2.4 Diameter of armour wire mm 1.6 2.0 2.5 2.5 2.5 Thickness of outer sheath mm 1.8 2.1 2.4 2.6 3.0 Approximate overall diameter mm 26 37 46 55 67 Approximate net weight kg/km 1400 2600 4200 5800 8400 Test Voltage kV/5 min 3 3 3 3 3 Max. conductor resistance (200C) /km 1.2 0.44 0.25 0.16 0.12 Min. insulation resistance (200C) M-km 5 5 5 5 5

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3.29 SPECIFICATION FOR TERMINAL LUGS 3.29.1 SCOPE 1.1 This specification is for compression terminal lugs for use in connecting cables or conductors

to each other or to equipment. 1.2 This specification covers the following.

(i) Aluminium terminal lugs.

(ii) Copper terminal lugs.

(iii) Bi-metal terminal lugs

3.29.2 REFERENCES

The Following documents were referred to during the preparation of this specification and may be referred to. In case of conflict, the provision of this specification shall take precedence.

Unless otherwise specified, the latest revision, edition and amendments shall apply.

BS 91: Electrical cable soldering sockets.

3.29.3 TERMS AND DEFINITIONS

For the purpose of this specification, the definitions in the reference standards shall apply.

3.29.4 SERVICE CONDITIONS

See clause 1.5

3.29.5 MATERIALS AND FABRICATION 3.9.5.1 The terminal lug shall comprise one tube to be compressed on the conductor and one palm

with one hole to connect the lug on the network apparatus. 3.9.5.2 The lugs shall be free from defects which would be likely to cause them to be unsatisfactory

in service. 3.9.5.3 All parts of the lugs shall be either inherently resistant to atmospheric corrosion, both during

storage and in service. 3.9.5.4 The lugs shall be suitable for use on insulated cables, stranded or solidal and on stranded

conductors and shall correctly fit the cable or conductor it is intended for use. It shall have adequate cross sectional area and length.

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3.9.5.5 The current carrying capacity of the lugs shall be at least equal to the capacity of the conductor it is intended for.

3.9.5.6 The lugs shall be type 1 and the dimensions and hole size shall be as per the requirements of BS 91.

3.9.5.7 The lugs shall be suitable for installation by use of crippling tool.

3.29.6 PARTICULAR REQUIREMENTS 3.29.7 Copper Lugs. 3.29.7.1 The copper lugs shall be suitable for connecting stranded copper cables to the

equipment with copper terminating studs. 3.29.7.2 The lugs shall be made from copper as per the requirement of BS 91 and shall have a

single fixing hole.

3.29.8 Aluminium Lugs

3.29.8.1 The aluminium lugs shall be suitable for connecting stranded and solidal aluminium cables or stranded aluminium conductor or aluminium conductor steel reinforced (ACSR) to aluminium terminations.

3.29.8.2 The lugs shall be made of electrolytic, high strength corrosion resistant

aluminiumalloy. 3.29.9 Bi - metal Lugs 3.29.9.1 The bi-metal lugs shall be suitable for connecting aluminium cable to copper busbar

or equipment’s with copper terminal studs. 3.29.9.2 The bi-metal socket shall have the connection point which shall provide an effective

corrosion barrier between the dissimilar metals (copper and aluminium). 3.29.9.3 Friction welding between aluminium tube and copper palm of bi-metal lugs is not

accepted. 3.30 SPECIFICATION FOR CABLE GLANDS 3.30.1 SCOPE 1.1 This specification is for cable glands for use in terminating cables to equipment. 1.2 This specification covers the following. 3.30.2 SERVICE CONDITIONS

Clause 1.5

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3.30.3 MATERIAL AND CONSTRUCTION 3.30.1.1.1 The glands shall be free from defects which would be likely to cause them to be

unsatisfactory in service. 3.30.1.1.2 All parts of the glands shall be either inherently resistant to atmospheric corrosion, both

during storage and in service. 3.30.1.1.3 The glands shall be suitable for use on insulated cables, stranded or solidal and shall

correctly fit the cable it is intended for use. It shall have adequate cross sectional area and length.

3.30.2 REFERENCES

The Following documents were referred to during the preparation of this specification and may be referred to. In case of conflict, the provision of this specification shall take precedence.

Unless otherwise specified, the latest revision, edition and amendments shall apply. BS 91: Electrical cable soldering sockets.

3.31 SPECIFICATION FOR CONCRETE CABLE COVERS

3.31.1 SCOPE

This standard specifies requirements for concrete cable covers categorised as follows: (i) LV Hatari Slabs (ii) HT Hatari Slabs

3.31.2 SERVICE CONDITIONS

The cable covers shall be laid above power cables buried underground in soils of various types. High voltage cables are buried at depths of upto 1600mm while low voltage cables are buried at depths of 500mm.

The covers designated LV shall be used to cover cables operating at 240/415V (low voltage) while those designated HT shall be used to cover cables operating at higher voltages upto 66kV.

3.31.3 REQUIREMENTS

a) Materials and Construction

The product shall be made using Portland Cement conforming to KS02-1261, course aggregates size 3.2mm (1/8”) conforming to KS02-95, clean river sand and drinking quality water free from any visual contaminations. The product shall not contain additional admixtures and pigments. The composition of cement, sand and course aggregates shall be 1:3:6.

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Steel moulds shall be used in the manufacture of the product so as to ensure a smooth texture externally. The mould shall be accurately made to produce units of the dimensions, profiles and shapes shown in the drawings. The product shall be vibrated while on mould and shall be well cured thereafter. Lettering shown on the drawings shall be formed using accurately placed formers securely fixed in position. Cutting either uncured or hardened concrete shall not be permitted.

b) Dimensions

The cable covers are required in two sizes with dimensions as shown in table 1 and figures 1 and 2 attached.

Table 1: Cable Cover Sizes Size Dimension (L x W x H) mm HT 650 x 220 x 40

LV 350 x 150 x 40

c) Transverse Strength

When sampled and tested as per the method described in BS 7263: part 1: 1994, the failing loads shall be not less than the appropriate value given in table 2. Table 2: Transverse Strength of Cable Covers Size Minimum Failing Load (kN) HT 2

LV 1.5

d) Water Absorption

When tested as described in BS 7263: part 1: 1994, the water absorption shall not exceed 4% by mass.

e) Sampling

A sample of three products shall be taken from a consignment of not more than 1000 products. Each of the three products shall be taken from one of three approximately equal sections of the consignment to be tested. The consignment shall be deemed to comply with this specification if all the three samples pass the tests in 3.3, 3.4 and dimensions specified.

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f) MARKING

The following words shall be marked on the profiled side (upper) of each cable cover.

“HATARI – KPLC”

g) The following information shall be marked on the manufacturer’s certificate supplied with the cable covers.

Name, trademark of manufacturer The number and date of standard to which the cable cover complies Type of binder constituent (s) used Dimensions of the product Instructions

(all in English Language)

3.31.4 TESTS

The cable covers shall be tested according to the method of test described in BS 7263: part 1: 1994.

The manufacturer/supplier shall submit test certificates (issued by recognized authority) confirming compliance of the cable covers to the requirements of this specification.

3.31.5 REFERENCES

The following documents were referred to during the preparation of this specification, in case of conflict the requirements of this specification take precedence.

(i) BS 7263: Part 1: 1994 - Precast concrete flags, kerbs,channels,edgings & quadrants (ii) KS 02-95 - Kenya Standard specification for natural aggregates for Concrete. (iii) KS 02-1261 – Kenya Standard Methods for Chemical Analysis of Cement.

3.32 POLE MOUNTED LOW VOLTAGE CIRCUIT BREAKER 3.32.1 SCOPE

This specification covers the design, testing and manufacturing requirements of low voltage outdoor circuit breaker assembly. The LV circuit breaker assembly shall comprise of a molded case circuit breaker, its outdoor housing, indications and operating rod. The breaker shall be used to provide protection for the low voltage side for the following pole-mounted oil-immersed transformer substations: 50KVA 100KVA 200KVA

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315KVA 3.32.2 REFERENCES The circuit breakers, operating rod and/or housing shall be designed, fabricated and tested in accordance with the latest applicable standards of the International electromechanical commission and British Standards as shown below: IEC 60947: LV switchgear and controls BS 729: Hot dip galvanized coating on iron and steel articles. IEC 60354: Loading guide for oil immersed transformers 3.32.3 DEFINITIONS For the purpose of this specification, the definitions in IEC 60947 shall apply. 3.32.3 REQUIREMENTS 3.32.4 SERVICE CONDITIONS

Specified in clause 1.5 of Annex 3 Technical specifications.

Further, the breaker and assembly shall be suitable for continuous outdoor operation in tropical areas at altitudes of up to 200m above sea level, humidities of up to 90%, average ambient temperature of +30ºC with a minimum of -1ºC and a maximum of +40ºC and saline conditions along the coast. The assembly shall be exposed to direct sunlight.

3.32.5 LV CIRCUIT BREAKER

The circuit breaker shall be mounted inside an enclosure conforming to IP-54.The enclosure will form an integral part of the circuit breaker assembly. The circuit breaker shall be 3phase 4 wire molded case type with air as the arc quenching medium. The circuit breaker shall be capable of being operated (RESET or ARM /ON/OFF) from the ground level by means of an operator’s rod (link sticks). Facilities to insert the operator’s rod shall be provided on the housing. Mechanical indications for ON (red) and OFF(green) shall be connected to the housing so as to be seen from the ground level. The main contacts shall be separate from the arc-breaking contacts. The main contacts shall be made of electrolytic copper and shall be silver faced. The arcing contacts shall be non-welding and conductive. The terminals shall be screw type and capable of accommodating the rated cable size.

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The circuit breaker shall have three main elements viz., (a) thermal overload protection, (b) short circuit current sensing (c) latching and tripping. The circuit breaker shall have a label indicating the size of the applicable transformer. Thermal overload protection using transformer thermal replica Each phase of the breaker shall be fitted with a thermal overload protection. The thermal overload sensing device shall be coordinated thermally with the transformer rating to follow as close as possible the variations of winding temperature due to load fluctuations and ambient temperatures. The manufacturer shall provide the formula for the oil-immersed transformer thermal model used and time-current curves in the protection for each size of the transformer. The following information could be used The top oil temperature rise for the transformers is 55C The type of oil used is mineral oil (for determination of oil time constant ) A signal light (on each phase), controlled by the thermal overload relay shall come on when the loading reaches 75% indicating that the transformer is almost fully-loaded and up-rating or load balancing exercise need to be scheduled. The thermal overload relay shall trip out the breaker when the overload reaches 90% of the transformer full rating The signal lights shall be positioned and wired on the housing so as to be visible from the ground level. Short circuit sensing device A short circuit sensing element shall provide instantaneous tripping of the circuit breaker under high fault current conditions. The short-circuit element shall have a mechanically reset indication/flag (marked S/C trip) when operated. The indication shall be connected on the housing so as to be seen from ground level. Mechanical Tripping and latching The circuit breaker shall be opened via the protection devices (thermal and short circuit) and/or manually via the operator’s rod (link stick). The circuit breaker shall be trip free. Closing of the breaker after opening shall be achieved by resetting or arming the breaker first. 3.32.6 HOUSING OF CIRCUIT BREAKER The circuit breaker housing shall be outdoor type conforming to IP-54. The housing shall be made of any of the following:

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hot dip galvanized steel finished in epoxy fiberglass fiber glass/steel combination

The housing shall be provided with a lockable hinged door. The housing shall be well ventilated, vermin proof and with brackets for mounting on circular poles having diameter of 170-270mm at point of installation. The housing shall have a label indicating the size of applicable transformers. The housing shall be equipped with the following:

It shall have 8 No. cable entry holes for incoming and outgoing cables (sized appropriately for the transformers mentioned in the scope) .All cable entry holes shall be from the bottom

3 number signaling lights for overload condition (at 75% loading) 2 mechanical flags : for overload trip (marked O/L) and 1 for short circuit trip

(marked S/C) ON/OFF indications Reset/On/off knob connectable to an operating rod.

3.32.7 INSTRUCTIONS, MARKING AND PACKING Instructions for storage, handling and installation of the breaker and housing shall be submitted in the English Language. All breakers and housing shall be clearly and indelibly marked by the manufacturer to indicate the following:

the manufacturer’s identification mark and reference/catalogue number

the breaker ratings

The circuit breaker shall have a label indicating the size of the applicable transformer.

The circuit breaker housing shall have a label indicating the size of the applicable transformers.

the manufacturer’s identification mark and a part number on all components forming part of

an accessory. This part number shall be referenced in the bill of materials. Components that are physically impossible to mark shall be individually packed and the packaging shall be marked.

f) the expiry date (visible on the packaging of all components or consumables that are

subjected to a shelf life limitation). These components or consumables shall be individually packed.

3.32.8 RATINGS The specific rating of each breaker is as specified in the Table 2 below. The following Table 1 gives the general ratings.

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TABLE 1: General Ratings Highest rated Voltage of Circuit Breaker 600 V ac Applied Voltage of the Circuit Breaker 433Vac ph-ph, Rated insulation voltage 1000V No. of phases 3phase 4 wire Frequency 50hz Power frequency withstand 1 minute 4KV Rated impulse voltage 6 KVp TABLE 2: Specific Ratings 50KVA Tx 100KVA Tx 200KVATx 315KVA Tx Rated current ( In)

70A 140A 280 A 450A

Minimum Short circuit break capacity

10KA 20KA 40KA 65KA

Short circuit make capacity

25KA 50KA 100KA 163KA

Hole area at housing cable entry point

50mm2 50mm2 100mm2 2 x 100mm2

Overload current/time curve

To provide To provide To provide To provide

Short circuit device pickup

6x In 6x In 6x In 6x In

Short circuit device delay

Instantaneous Instantaneous Instantaneous Instantaneous

3.32.9 TESTS AND INSPECTION The circuit breakers shall be tested as per IEC 60947 and the requirements of this specification. It shall be the responsibility of the manufacturer to perform or to have performed all the tests specified. Copies of previous Type Test Reports certified by the National Testing/ Standards Authority of the country of manufacture or its accredited testing laboratory (copy of Accreditation Certificate to be attached) shall be submitted with the tender for the purpose of technical evaluation, all in English.

The following type tests reports shall be provided: Trip Device Calibration Check Test. AC Dielectric Withstand-Voltage Test Temperature rise Test Overload Switching Test Endurance Test (Mechanical and Electrical)

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Short-Circuit Current Tests

The following routine tests shall be carried out after manufacturing: Calibration. Control, Secondary Wiring and Devices Check Tests Temperature rise Test AC Dielectric Withstand Tests Endurance Test (Mechanical and Electrical) No-Load Operation Tests

NB: Test reports of the above Routing shall be submitted with the offer.

Prior to the manufacture of circuit breaker assembly on order KPLC shall inspect the manufacturing facility and the quality management system. Upon completion of manufacturing process, the circuit breaker assembly shall be subject to inspection by KPLC Engineers at place of manufacture and tests carried out on samples picked at random in their presence. Test reports shall be completed and made available for approval before shipment/delivery to KPLC. 3.32.10 SPARE PARTS AND RELATED ACCESSORIES The spare parts and related accessories shall be fitted from the front, without additional wiring and with the minimal possible use of tools. All the electrical and mechanical accessories must be easily replaceable. All the electrical accessories shall be pre-wired and installable with plug-in connectors. The following spare parts and accessories shall be required to be compliant with these specifications: 10% spare trip assembly for each type used in the circuit breaker elements. 10% spare close assembly for each type used in the circuit breaker elements. 10% spare protection unit for each type used in the circuit breaker elements.

3.32.11 TECHNICAL DOCUMENTATION 3.32.11.1 The Bidder shall submit a clause by clause statement of compliance with these

specifications together with copies of the manufacturer’s catalogues, brochures, technical data, drawings, bill of materials and test certificates clearly marked to support each clause, all in English for evaluation. The manufacturer’s type reference/designation of the item offered shall be indicated.

3.32.11.2 The Bidder shall submit (from the manufacturer) a list of names and addresses of previous purchasers (utilities) giving year of delivery and quantities supplied during the past five years.

3.32.11.4 In the case of tender award, technical details and detailed drawings for the circuit breaker assembly to be supplied shall be submitted to KPLC for approval before manufacture commences. The drawings shall include all the accessories and components to be supplied

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3.33 EP VOLTAGE REGULATING TRANSFORMERS (AUTOMATIC VOLTAGE REGULATORS)

3.33.1 SCOPE 3.33.1.1 This specification is for oil – immersed, air – cooled step voltage regulating

transformers for 33kV distribution system operated at 50 Hz. 3.33.1.2 This specification covers transformers of the following voltage ratios and ratings.

(i) 33000/33 000+/-10% volts single phase step voltage regulating transformer:-330

KVA. (ii) 33000/33 000+/-10% volts single phase step voltage regulating transformer:-

660KVA

(iii) 11000/11000 +/- 10%. 3.33.2 REFERENCES The following documents were referred to during the preparation of this specification; in case of

conflict the requirements of this specification take precedence. ANSI/IEEE C57.15 : Standard Requirements, Terminology, and Test Code for Step-Voltage and Induction-Voltage Regulators IEC 60076: Power Transformers

BS 381C: Specification for colours for identification, coding and special purposes

IEC 60296: Specification for unused mineral insulating oil for transformers and switchgear

IEC 60354: Loading guide for oil – immersed power transformers. 3.33.3 TERMS AND DEFINITIONS

For the purpose of this specification, the definitions in ANSI/IEEE C57.15 shall apply. 3.33.4 REQUIREMENTS 3.33.5. SERVICE CONDITIONS 3.33.5.1 Operating conditions The Step voltage regulating transformers shall be suitable for continuous operation in tropical areas

with the following atmospheric conditions.

(e) Altitude: From sea level up to 2200m above mean sea level.

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(f) Pollution: heavy saline atmosphere in coastal areas

(g) Humidity: upto 90%

(h) Ambient temperatures of +30 C average, (+40 C Max. and -1 C Min).

(i) Isokeraunic level: Upto 180 thunderstorm days.

3.33.5.2 System characteristics

The transformer shall be connected to a distribution overhead system which is of bare conductor construction

The primary and secondary system have a nominal voltage of 33000 volts system with highest voltage of 36000 volts. Both systems are 3 – phase 3 – wire 50 Hz.

3.33.5.3 DESIGN DETAILS AND INFORMATION

3.33.5.3.1 The regulators furnished under this specification shall be designed, manufactured, and tested in accordance with ANSI Standard C57.15, latest revision thereof. That Standard shall form part of this specification.

3.33.5.3.2 The Regulators shall be designed to be connected to a 33kv 3 phase system in a closed delta formation.

3.33.5.3.3 Where possible the design shall have internal voltage tap settings that allow star connections . The internal tappings shall be clearly marked and shall apply to both primary and secondary windings of the transformer such that the control voltage does not change for all applications.

3.33.5.3.4 Drawings and documentation for each size of transformer tendered shall be given, clearly detailing important dimensions, clearances, accessories, fittings and any special feature of your design.

3.33.5.4 INTERNAL FEATURES CONSTRUCTION

3.33.5.4.1 The step-type voltage regulators shall be of outdoor, single-phase, oil-immersed construction.

3.33.5.4.2 The cooling shall be ONAN. Forced air (FA) ratings are not acceptable.

3.33.5.4.3 Loading shall be as per IEC 60354

3.33.5.4.4 The regulator shall be furnished with new IEC 60296 (class 1 un-hibited) oil.

3.33.5.4.5 The manufacturer shall provide the chemical composition and properties of the oil and replacement cycle.

3.33.5.4.6 The voltage regulators shall be completely self-contained and provide +/-10% regulation in thirty-two (32) steps of approximately 5/8% each

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3.33.5.4.7 The regulators shall be designed such that they can be partially or completely untanked for inspection and maintenance without disconnecting any internal electrical or mechanical connections.

3.33.5.4.8 The cores shall be constructed of high quality low loss grain oriented electrical steel laminations. 3.33.5.4.9 The design shall ensure no hot sections due to overfluxing or circulating currents across the laminations. The flux density at any point shall not exceed 1.65 tesla.

3.33.5.4.10 The tap-changing mechanism shall be motor-driven, quick-break slow-make type, and shall be completely oil-immersed.

3.33.5.4.11 A switching reactor shall be provided in the tap changing. Where necessary equalizer windings shall be provided to balance the reactor voltage.

3.33.5.4.12 The regulator shall be of a sealed-tank construction to permit operation at oil and winding hot spot temperature of 55 and 65°C rise respectively without increasing the oxidation rate of the oil.

3.33.5.4.13 A pressure-relief device shall be supplied which vents at approximately 27.5 kiloPascals (4 psig).

3.33.5.4.14 The complete regulator shall be painted to protect against corrosion, and the final colour of the exterior surface shall be Dark Admiralty Grey colour No. 632 as per BS 381C with a coating of not less than 80 microns.

3.33.5.4.15 The inside of the tank shall be coated with oil resisting varnish or paint so that oil cannot come into contact with tank or metal at any point.

3.33.5.4.16 The regulator winding shall include thermally-upgraded insulation to permit operation of the regulator up to 65°C rise without loss of life to the insulating system.

3.33.5.4.17 At 65°C rise, the regulator shall provide 12% extra current capacity over the base current rating.

3.33.5.4.18 A suitably patterned, epoxy-coated insulation paper shall be used in the winding. Prior to assembly of the core and winding assembly, the winding shall be baked with sufficient mechanical pressure exerted on the winding to assure a complete bonding of the insulation to improve its short-circuit current withstand capabilities as specified by ANSI/IEEE C57.15.

3.33.5.4.19 The windings shall be of high conductivity electrolytic copper capable of sustaining short circuit forces on the transformer as required in clause 3.37.4.3.18.

3.33.5.4.21 An appropriately rated current transformer shall be installed be capable of handling the burden from the metering and control functions.

3.33.5.4.21 The series windings shall have Load bonus feature which shall allow extra current flow above the rated for reduced regulation limits (the upper limit being +/- 10%).

136

The maufacturer shall provide a table showing the load bonus versus regulation limits settings.

3.33.5.5 EXTERNAL FEATURES CONSTRUCTION 3.33.5.5.1 The tank shall be round, sealed and constructed of mild steel plates fabricated by pressing or rolling . 3.33.5.5.2 Three bushing designations (S, L, and SL) shall be permanently marked on the regulator cover adjacent to the bushings. The S, L, and SL bushings must be interchangeable with each other. 3.33.5.5.3 Each bushing shall include Clamp-type terminal as indicated:

Current rating Clamp diameter Upto 150 AMPS 5 to 14.5 mm Above 150 AMPS 5 to 27mm

3.33.5.5.4 All regulators shall be provided with an external metal oxide varistor (MOV) bypass arrester connected across the series winding. 3.33.5.5.5An external oil sight gauge shall be provided which indicates oil level at 25°C ambient. 3.33.5.5.6 An external dial-type position indicator with drag hand and load bonus adjustment shall indicate the tap changer position. The position indicator shall be mounted above the oil level and slanted downward at a 45-degree angle for ease of reading when the regulator is pole mounted. 3.33.5.5.7 Mounting bosses shall be provided for the installation of lightning arresters adjacent to the source (S), load (L), and source-load (SL) bushings. The bosses shall be fully welded around their circumference. Spot welding is not acceptable. 3.33.5.5.8 Three number surge arrestors of rated voltage 36kv , 10KA discharge class 2 shall be connected to the S, L and S-L bushings. 3.33.5.5.9 All regulators shall NOT have a drain valve and upper filter press connection. These shall be sealed. 3.33.5.5.10 A handhole with cover shall be provided on top of the regulator for inspection purposes and for access to terminals used for reconnection of regulators for lower-voltage operation. 3.33.5.5.11 The Regulators shall be provided with a base suitable for securing them to a pad or elevating structure. All regulators must be capable of being secured to elevating structures. 3.33.5.5.11 Each regulator shall be provided with two laser-etched nameplates, one mounted on the

controlenclosure and the other mounted on the regulator tank. The nameplate shall have technical details of the regulator. The nameplates shall have the manufacturer code and serial number with a 6 mm (0.25") minimum height.

3.33.5.6 RATINGS 3.33.5.6.1 Technical specifications:

137

The technical specifications for the regulator shall be as shown in the table for service conditions as per ANSI/IEEE C57.15. The manufacturer however shall apply appropriate de-rating factors to suit the service conditions mentioned in clause 3.37.4.1 . The corrected values shall be entered in the appendix A.

Cooling Medium oil Number of phases 1 Rated Voltage 36Kv Frequency 50 Hz Rated current for 330KVA regulator 100Amps Rated current for 660KVA regulator 200Amps Rated short time current 21kA Duration of short circuit 2seconds Impulse withstand voltage (BIL) 200kV One minute power frequency withstand voltage 90Kv

3.33.5.6.2 The regulator shall be capable of carrying its full normal rated current plus 12% boost continuously under the tropical conditions stated, and at any tappings without the temperature rise in the hottest region exceeding 55 C and 65 C in oil and winding respectively.

3.33.5.6.3The minimum external electrical clearances and minimum creepage distance of the

bushing shall be as indicated below:

Nominal System Voltage between Phases 33kV Maximum system voltage 36Kv Minimum clearances between phase to earth mm 480 Minimum Clearances between phases mm 435 Creepage distance mm 900 3.33.5.6.4The guaranteed maximum sum total of the regulator losses, measured at full load

operation, unity power factor and rated voltage shall be as indicated in the table below. The loss measurements shall be adjusted to 75 degree Celsius. Further more, values of measured no load and load losses at 100%, 75%, 50% and 25% regulator loading shall be provided.

For purpose of comparison of tenders, measured total winding losses and core losses at 100%

loading shall be used as specified in evaluation criteria.

RATING (KVA)

PHASE SYSTEM VOLTAGE (KV)

TOTAL REGULATOR LOSSES e.g. (Fe + Cu) (watts)

330 1 33 660 1 33

3.33.5.7 REGULATOR CONTROL BOX 3.33.5.7.1 The regulator control panel shall be mounted in a weather-resistant enclosure which is capable of being padlocked. The control enclosure shall have an external welded ground boss. 3.33.5.7.2 The control panel shall be hinge-mounted and designed for easy replacement. The front

panel assembly shall be constructed to provide direct control interchange ability without

138

removal of the control enclosure. Visible means shall be provided to de-energize the control and short the current transformer prior to control testing or removal.

3.33.5.7.3 All leads in the control enclosure shall be either color coded or labeled for easy

identification. 3.33.5.7.4 All printed circuit boards shall be conformal coated for fungi and moisture protection. 3.33.5.7.5 A ratio correction transformer shall be provided inside the enclosure for easy access to fine voltage adjustment. Ratio correction taps and the corresponding system voltage shall be clearly identified on the nameplates.

3.33.5.7.6 The control panel shall have a temperature range of -40°C to +85° C and include the following features:

a. A three-position voltage source switch, labeled INTERNAL-OFF-EXTERNAL, which allows the regulator to be operated from an internal potential source, operated from an external source, or de-energized

b. A three-position, AUTO/REMOTE-OFF-MANUAL switch that allows automatic or

manual operation of the regulator. Supervisory motor control shall be permitted only when the switch is on the AUTO/REMOTE position.

c. A spring-loaded three-position manual RAISE-OFF-LOWER toggle switch, which shall

only be active when the control switch is in the MANUAL position. d. A position indicator drag hand reset switch. e. A two-position supervisory ON-OFF switch which, in the OFF position, inhibits motor

control and parameter changing via digital SCADA, but allows reading of the control data base via SCADA.

f. A neutral position indicating lamp that is actuated via the tap changer to provide neutral

indication.

g. An operations counter which counts every tap change.

h. Separate motor and panel fuses which are replaceable from the front panel. Fuse size shall be clearly marked at each fuse. One set of spare fuses shall be included in the control enclosure.

i. A means shall be provided to indicate whether the voltage is inside or outside the set voltage band.

j. Voltmeter test terminals shall be supplied which connect to the secondary of the load side (L bushing) of the regulator.

k. External voltage source terminals shall be supplied to allow tap changer and control

operation from an external 120 vac source. An interlocking means shall be provided to prevent energizing the high-voltage bushings from the external source.

139

3.33.5.7.7 The voltage regulator shall be microprocessor based and have provisions for programming of the following parameters:

a. Set voltage shall be adjustable from 100.0 to 135.0 volts with a maximum increment of 0.5.

b. Set voltage bandwidth shall be adjustable from 1.0 to 6.0 volts with a maximum increment of 0.1 volt.

c. Time delay shall be adjustable from 5 seconds to 180 seconds with a maximum of 5 second increments.

d. Line drop compensation resistance and reactance settings which are adjustable from -24.0 to 24.0 volts in increments of 0.2 volts maximum. A means shall be provided to set the polarity.

3.33.5.7.8 The voltage regulator control shall include the following features: a.) A digital metering package of Class 1 accuracy which shall provide the following

information: 1. Instantaneous values of load voltage, compensated voltage, current, power factor,

kVA load, kW load, kvar load, voltage harmonics, and current harmonics. Voltage and current harmonics shall include, at a minimum, total harmonic distortion.

2. Maximum demand values of load voltage, compensated voltage, current, kVA

load, kW load, and kvar load. For each of these values, the present value, highest value since last reset, and lowest value since last reset shall be provided. Highest and lowest values shall be time and date tagged. Power factor at maximum and minimum kVA load shall be provided. Metering values must be available for both forward and reverse power flow conditions.

b. A tap position indication capability, which tracks the movement of the

tap changer motor, shall provide the present tap position and the highest and lowest positions since last reset. The highest and lowest values shall be date and time tagged.

c. A voltage limiting capability which prevents the regulator from making additional tap

changes once the regulator output voltage meets a programmed upper- or lower-limit setting. If the source voltage should change, causing the regulator output voltage to exceed either limit, the control shall automatically run the regulator so as to keep the voltage within the limit settings.

d. A voltage reduction (load shedding) capability which consists of local and remote

reductions from 0 to 10 %.

e. A Reverse Power Flow Detector which automatically senses a power reversal and can provide indication that a power reversal is taking place. In case of reverse power flow the tap change shall tap to neutral position and inhibit further tap changing.

f. Operation of the regulator during system voltage instability period may result in total

voltage collapse. Means to detect and mitigate this shall be provided.

g. The control shall have provisions to allow remote override of regulator operation via discrete (analog) supervisory control. Terminals shall be provided on the back panel as follows:

140

For motor raise: Two terminals for normally-open, momentary-close contacts. For motor lower: Two terminals for normally-open, momentary-close contacts. For auto inhibit: Two terminals for normally-closed, latch-open contacts.

h. The control shall be capable of digital communications through a communications port located on the main circuit board. The control shall be capable of communicating via the communications port without the addition of a protocol conversion board.

i. A 9-pin data RS243 port shall be provided on the front panel for the temporary

connection of a personal computer or a hand held reader. 3.33.5.8 ACCESSORIES AND SPARES

The following accessories and spares shall be provided [ a ] Long length cable to allow remote placement of the regulator control. The cable shall be 7

meters long and shall be preconnected at the factory. [ b ] A hand-held, battery-operated device Data Reader , which temporarily connects to the

control, and reads and stores all metering and control set values. The device shall be able to store information from up to 20 regulator controls. The device shall be compatible with IBM®-PC, -XT, or -AT, or compatible computers. A device-to-control cable shall be included.

[c ] A thermostatically-controlled heater assembly to reduce moisture in areas of high humidity.

The heater assembly shall include an ON-OFF switch. In the ON position, a thermostat in the heater assembly shall activate the heater at approximately 30°C (85°F) and turn it off at approximately 40°C (100°F).

3.33.5.9 EVALUATION OF TENDERS

3.34 TAPES 3.34.1 INSULATING TAPES 3.34.2 SCOPE

This specification covers the design, manufacture testing and supply of insulating and protective tapes for use on cable joints, terminations and repairs, colour coding of cables, conductor and other electrical installation. This specification covers the following tapes Impregnated fabric tapes Adhesive PVC electrical tapes Adhesive PVC colour coding tapes

3.34.3 REFERENCES

141

The equipment shall comply with the latest edition and amendments of the Standards listed herein. SABS 122:- Pressure-sensitive adhesive tapes for electrical purposes (Metric units)

3.34.4 MATERIAL AND CONSTRUCTION (a) Impregnated fabric Tape

The base metal shall be non-woven synthetic fabric, manufactured from high quality fabrics that when impregnated, the finished tape shall be of uniform quality and have the properties and characteristics as specified in this specification. The fabric shall not shrink, or rot and have a high tensile strength. The tape shall be suitable for use in protecting cable joints both indoor and outdoor and suitable for application on cables installed both above and below ground.

The tape shall be suitable for application on dry and wet surfaces and not affected by water, acid, salts or soil organic.

The tape shall be fully impregnated with a neutral petroleum compound with inert fillers and corrosion inhibitors to obtain a good electrical characteristics required for insulating purposes. The tape shall have a nominal width of not less than 25mm.

The tape shall have the following characteristics

Average thickness 1.00mm Average weight 1.50 kg/m2 Breaking strength 3N/mm Average elongation at break 10% Breakdown voltage 16kV Approximate roll length 10m Maximum service temperature 70C

(b) Adhesive PVC electrical tapes

The base material shall be electrical grade polyvinyl chloride (PVC) or its copolymer. The tape shall have a rubber-based, pressure-sensitive adhesive on one side. The adhesive shall be filly applied to give a good quality application. There shall be no sign of adhesive transfer when the tape is pulled from the roll. The tape shall be smooth and free from lumps or bare spots and other defects, which would likely cause them to be unsatisfactory in service. The tape shall be flame retardant and weather resistant and shall remain stable when maintained at a temperature not more than 70C. The tape shall have a nominal width of not less than 25mm and shall be wound on cores.

142

The tape shall be suitable for application in primary electrical insulation of all wires and cables rated 600 volts.

The tape shall have the following characteristics Average thickness 200m Breaking strength 3N/mm Average elongation at break 120% Breakdown voltage 10kV Approximate roll length 20m Voltage rating 600V Insulation resistance 1 x 106 M Adhesive strength 170mN/mm of width of tape Colour Black, Blue, Green, Red or yellow

(c) Adhesive PVC colour coding tapes

The base material shall be polyvinyl chloride (PVC) or its copolymer. The tape shall have a rubber-based, pressure-sensitive adhesive with fade resistant colours on one side. The adhesive shall be filly applied to give a good quality application. There shall be no sign of adhesive transfer when the tape is pulled from the roll. The tape shall be smooth and free from lumps or bare spots and other defects, which would likely cause them to be unsatisfactory in service. The tape shall have a nominal width of not less than 25mm and shall be wound on cores. The tape shall be suitable for application in phase identification and colour coding of cables. The tape shall have the following characteristics Average thickness 200m Breaking strength 3N/mm Average elongation at break 120% Breakdown voltage 10kV Approximate roll length 20m Maximum service temperature 70C Adhesive strength 170mN/mm of width of tape Colour Black, Blue, Green, Red or yellow

3.34.4 TESTS (a) The tapes shall be inspected and tested in accordance with the requirement of this

specification.

(b) The following tests shall be done by the manufacturer, and test certificates submitted for approval by KPLC before materials are submitted.

143

(c) Fabric tapes

Dimension Breaking strength Elongation at break

(d) PVC tapes

Dimensions Breaking strength Elongation at break Adhesion strength Insulation resistance Breakdown voltage Resistance to adhesive transfer.

(e) Barbed wires 3.34.5 MARKING, LABELING AND PACKING

Instructions for use, care, and storage shall be submitted. Each roll of tape shall be clearly, indelibly and permanently marked with the following information (in the English language): Name and trademark of manufacturer. Thickness, width and length of tape Colour of tape (for PVC tapes) The maximum working temperature Shelf life Date of manufacture.

3.35 OPERATION DEVICES AND PROTECTION SYSTEMS

Operation devices consisting of single and three pole disconnectors shall be installed at locations specified by the designer. The disconnectors shall be easily accessible during normal conditions. They will be fixed in such a way that they cannot be closed by the action of gravity. Their characteristics shall be capable of meeting the maximum rated current of the circuit.

3.36 PROTECTION AGAINST OVERVOLTAGE Protection against overvoltage will consist of surge diverters at locations specified by the

designer. 3.37 ENVIRONMENTAL REQUIREMENTS

144

The Contractor shall undertake to complete all works in accordance to the Environmental and Social Management Plan for the project that has been prepared by KPLC 3.38 WAYLEAVES.

All construction work shall only be carried out over private land and reserve areas after appropriate wayleaves consent to be obtained by KPLC.

Kenya Power and Lighting Company VI Group Schemes Distribution Reinforcement and Upgrading Technical Specifications and Drawings

Technical Schedules 2010 Group Schemes

4.  TECHNICAL SCHEDULES ............................................................................................................................ 2 

PREAMBLE ......................................................................................................................................................... 2 4.1.  TECHNICAL SCHEDULES SUBSTATIONS ............................................................................................ 2 SCHEDULE VI 8A - TECHNICAL GUARANTEES, DISTRIBUTION TRANSFORMERS ................................. 3 

SCHEDULE VI-8b - INFORMATIVE DATA, DISTRIBUTION TRANSFORMER ............................................. 5 SCHEDULE VI 8a - TECHNICAL GUARANTEES, DISTRIBUTION TRANSFORMERS SINGLE PHASE ....... 8 SCHEDULE VI-8b - INFORMATIVE DATA, DISTRIBUTION TRANSFORMER SINGLE PHASE ................ 10 

4.2.  TECHNICAL SCHEDULES AUTORECLOSERS .................................................................................. 12 

Kenya Power and Lighting Company VI Group Schemes Distribution Reinforcement and Upgrading Technical Specifications and Drawings

Technical Schedules 2010 Group Schemes

4. TECHNICAL SCHEDULES  

PREAMBLE

(a) The Technical Schedules shall be filled in and completed by the Bidder, and submitted with the Bid. 

(b) All documentation necessary to evaluate whether the equipment offered is in accordance with this Specification shall be submitted with the Bid.

(c) All data entered in the Schedules of Technical Guarantees are guaranteed values by the Bidder and cannot be departed from whatsoever.

(d) All data entered in the Schedules of Informative. Data are also guaranteed values by the Bidder. These data may only be altered following the Project Manager's written consent. 

4.1. TECHNICAL SCHEDULES SUBSTATIONS  

Kenya Power and Lighting Company VI Group Schemes Distribution Reinforcement and Upgrading Technical Specifications and Drawings

Technical Schedules 2010 Group Schemes

SCHEDULE VI 8a ­ TECHNICAL GUARANTEES, DISTRIBUTION TRANSFORMERS     Sheet 1 of 2

DISTRIBUTION TRANSFORMER Guaranteed Data

Item Particulars Unit 33/0.433KV 11/0.4 kV

1. Continuous Maximum Rating C.M.R. kVA

2. Normal voltage between phases at no load a) H.V. Volts b) L.V. Volts

3. Tappings a) Plus % b) Minus %

4. Performance Data at Sea Level, corrected at 75% a) No load loss at normal primary voltage watts b) No load loss at 10% primary over voltage watts c) Load loss at C.M.R. watts d) Impedance volts at C.M.R. and normal ratio % e) Regulation at C.M.R. and unity power factor % f) Regulation at C.M.R. and 0.8 power factor % g) Max temperature rise at C.M.R.: i) Top oil by thermometer oC ii) Average winding by resistance iii) “Hot Spot” corresponding to (ii)

Kenya Power and Lighting Company VI Group Schemes Distribution Reinforcement and Upgrading Technical Specifications and Drawings

Technical Schedules 2010 Group Schemes

SCHEDULE VI-8a - TECHNICAL GUARANTEES, DISTR. TRANSFORMERS Sheet 2 of 2

DISTRIBUTION TRANSFORMER Guaranteed Data

Item Particulars Unit 33/0.433KV 11/0.433 kV

5. Type of insulation used on windings a) H.V. b) L.V.

6. Lightning Impulse Insulation level of: a) H.V. winding kVpk b) L.V. winding kVpk c) Tap change equipment and connections i) To earth kVpk ii) Between contacts kVpk

7. Are test certificates supplied supporting the level stated in Clause 6

Yes/No

8. Silica gel Breather a) Make of unit fitted b) Size of unit

Kenya Power and Lighting Company VI Group Schemes Distribution Reinforcement and Upgrading Technical Specifications and Drawings

Technical Schedules 2010 Group Schemes

SCHEDULE VI-8b - INFORMATIVE DATA, DISTRIBUTION TRANSFORMER Sheet 1 of 2

DISTRIBUTION TRANSFORMER

Item Particulars Unit 33/0.433KV 11/0.433 kV

1. Transformer type (sealed or breathing)

2. Type of windings HV LV

3. Type of insulation HV winding LV winding

4. Type of tap changer

5. Tap changer designation

6. Type of axial coil supports HV winding LV winding

7. Winding conductor material HV winding LV winding

8. Core laminations designation -

9. Specific core loss w/cm3

10. Type of bushings HV LV

Kenya Power and Lighting Company VI Group Schemes Distribution Reinforcement and Upgrading Technical Specifications and Drawings

Technical Schedules 2010 Group Schemes

Kenya Power and Lighting Company VI Group Schemes Distribution Reinforcement and Upgrading Technical Specifications and Drawings

Technical Schedules 2010 Group Schemes

SCHEDULE VI-8b - INFORMATIVE DATA DISTRIBUTION TRANSFORMERS Sheet 2 of 2

DISTRIBUTION TRANSFORMER

Item Particulars Unit 33/0.433KV 11/0.433 kV

11. Bushing insulator material

HV LV

12. Creepage distance across bushings HV mm LV mm

13. Type of cooling system

14. Total oil quantity k

15. Total weight

16. Volume of conservator tank l

17. Overall dimensions Length mm Width mm Height mm

18. State all standards applied underneath:

19. State identity of manufacturer underneath:

Kenya Power and Lighting Company VI Group Schemes Distribution Reinforcement and Upgrading Technical Specifications and Drawings

Technical Schedules 2010 Group Schemes

SCHEDULE VI 8a - TECHNICAL GUARANTEES, DISTRIBUTION TRANSFORMERS SINGLE PHASE

Sheet 1 of 2

DISTRIBUTION TRANSFORMER Guaranteed Data

Item Particulars Unit 33/0.24KV 11/0.24 kV

1. Continuous Maximum Rating C.M.R. kVA

2. Normal voltage between phases at no load a) H.V. Volts b) L.V. Volts

3. Tappings a) Plus % b) Minus %

4. Performance Data at Sea Level, corrected at 75% a) No load loss at normal primary voltage watts b) No load loss at 10% primary over voltage watts c) Load loss at C.M.R. watts d) Impedance volts at C.M.R. and normal ratio % e) Regulation at C.M.R. and unity power factor % f) Regulation at C.M.R. and 0.8 power factor % g) Max temperature rise at C.M.R.: i) Top oil by thermometer oC ii) Average winding by resistance iii) “Hot Spot” corresponding to (ii)

Kenya Power and Lighting Company VI Group Schemes Distribution Reinforcement and Upgrading Technical Specifications and Drawings

Technical Schedules 2010 Group Schemes

SCHEDULE VI-8a - TECHNICAL GUARANTEES, DISTR. TRANSFORMERS SINGLE PHASE Sheet 2 of 2

DISTRIBUTION TRANSFORMER Guaranteed Data

Item Particulars Unit 33/0.24KV 11/0.24 kV

5. Type of insulation used on windings a) H.V. b) L.V.

6. Lightning Impulse Insulation level of: a) H.V. winding kVpk b) L.V. winding kVpk c) Tap change equipment and connections i) To earth kVpk ii) Between contacts kVpk

7. Are test certificates supplied supporting the level stated in Clause 6

Yes/No

8. Silica gel Breather a) Make of unit fitted b) Size of unit

Kenya Power and Lighting Company VI Group Schemes Distribution Reinforcement and Upgrading Technical Specifications and Drawings

Technical Schedules 2010 Group Schemes

SCHEDULE VI-8b - INFORMATIVE DATA, DISTRIBUTION TRANSFORMER SINGLE PHASE

Sheet 1 of 2

DISTRIBUTION TRANSFORMER

Item Particulars Unit 33/0.24KV 11/0.24 kV

1. Transformer type (sealed or breathing)

2. Type of windings HV LV

3. Type of insulation HV winding LV winding

4. Type of tap changer

5. Tap changer designation

6. Type of axial coil supports HV winding LV winding

7. Winding conductor material HV winding LV winding

8. Core laminations designation -

9. Specific core loss w/cm3

10. Type of bushings HV LV

Kenya Power and Lighting Company VI Group Schemes Distribution Reinforcement and Upgrading Technical Specifications and Drawings

Technical Schedules 2010 Group Schemes

SCHEDULE VI-8b - INFORMATIVE DATA DISTRIBUTION TRANSFORMERS SINGLE PHASE Sheet 2 of 2

DISTRIBUTION TRANSFORMER

Item Particulars Unit 33/0.24KV 11/0.24kV

11. Bushing insulator material

HV LV

12. Creepage distance across bushings HV mm LV mm

13. Type of cooling system

14. Total oil quantity k

15. Total weight

16. Volume of conservator tank l

17. Overall dimensions Length mm Width mm Height mm

18. State all standards applied underneath:

19. State identity of manufacturer underneath:

Kenya Power and Lighting Company VI Group Schemes Distribution Reinforcement and Upgrading Technical Specifications and Drawings

Technical Schedules 2010 Group Schemes

4.2. TECHNICAL SCHEDULES AUTORECLOSERS  SCHEDULE VI-9 - TECHNICAL GUARANTEES, MV EQUIPMENT AUTORECLOSERS Sheet 1 of 2

MV EQUIPMENT Guaranteed Data

Item Particulars Unit

AUTORECLOSER 33 KV 11KV -

1 Type 2 Interrupting medium 3 Insulating medium 4 Voltage rating: a) Nominal kV b) Maximum kV c) Power frequency kV d) Basic Insulation Level kV Current rating: a) Continuous A b) Short time 3 seconds A c) Interrupting A d) Closing and latching capability A 5 Interrupting cycles 6 Opening time (trip initiation to

contact separation) ms

7 Closing time (close initiation to contact make)

ms

8 Type of Operating mechanism: a) Trip mechanism b) Closing mechanism Type of control 9 Number of operations to lockout 10 Number of fast operations 11 Number of slow operations 12 Accessories a) Bushing cts Yes/no b) Metering amps Yes/no c) Remote trip Yes/no d) Remote close Yes/no

13 Dimensions: a) Height mm b) Width mm c) Depth mm Weight kg

SECTION VI

SCOPE OF WORK

Overhead Lines

VI 5.2 - i

2 - 5.0 Scope of work SOW-lines.doc Oct 2010 kplc

TABLE OF CONTENTS

SCOPE OF WORKS .................................................................................................................................... 1 

5.  GENERAL ............................................................................................................................................ 1 

5.1.  NEW LINES- 33KV, 11KV AND LOW VOLTAGE LINES ...................................................................... 2 5.1.1.  Western Region .............................................................................................................................. 2 5.1.2.  Mt Kenya Region ............................................................................................................................ 2 5.1.3.  Nairobi A Region ............................................................................................................................ 2 5.1.4.  Nairobi B Region and Coast Region ............................................................................................... 2 

5.2.  OPTIONAL WORKS SUMMARY .......................................................................................................... 3 5.2.1.  MT. KENYA ................................................................................................................................. 3 5.2.2.  NAIROBI A .................................................................................................................................. 4 5.2.3.  NAIROBI B AND COAST ................................................................................................................ 4 5.3.4.  WEST KENYA ............................................................................................................................. 4 

Kenya Power and Lighting Company VI 5.2 - 1 Contract Insert No Distribution Reinforcement and Upgrade Technical Specifications and Drawings

2 - 5.0 Scope of work SOW-lines.doc Oct 2010 kplc

SCOPE OF WORKS

5. General

The Bidder shall examine the scope of works in this section in close connection with the other documents and particulars forming these Bidding Documents. Special attention shall be paid to Technical Specifications, in which the general technical requirements are specified. The preliminary design drawings enclosed in are for bidding purposes only. If the Specifications and/or Drawings do not contain particulars of materials or goods that are necessary for the proper and safe completion, operation and maintenance of the equipment in question, all such materials shall be deemed to be included in the supply. In the event of any conflict between the Drawings and the Specifications, the latter shall prevail. In the event of any conflict between scaled dimensions and figures on the Drawings, the figures shall prevail. The scope of work covers supply of equipment, engineering and design, manufacture, testing before shipment and packing sea worthy or otherwise as required, delivery of all equipment CIP site, construction and installation and commissioning. Where the new line share the route with existing lines, the scope of work shall include all the necessary works/modifications that will be required to accommodate the lines along the same route. The hardware/fittings and conductors of the existing lines shall be re-used. Cross arms: Steel crossarms shall be used in all cases including re-conductoring Shield Wires: Shield wires shall are required for some the 33 kV lines. The standard size used by KPLC is 25 mm2.

Kenya Power and Lighting Company VI 5.2 - 2 Contract Insert No Distribution Reinforcement and Upgrade Technical Specifications and Drawings

2 - 5.0 Scope of work SOW-lines.doc Oct 2010 kplc

5.1. NEW LINES- 33kv, 11kv and Low Voltage lines

5.1.1. Western Region

Item Western Region Unit Length Equipment/materials: WES-200 New 33 kV OH lines in the western region, in 75mm2 ACSR

conductor and associated switchgear. km 47

New 11kV OH lines in the western region, in 75mm2 ACSR conductor and associated switchgear

57

New LV OH lines in the western region, in 50mm2 AA conductor

182

Works: WES-300 Civil works Lot WES-301 Erection and stringing Lot

5.1.2. Mt Kenya Region

Item Mt Kenya Region Unit Length Equipment/materials: Mt KE-200 New 33 kV OH lines in the Mt Kenya region, in 75mm2 ACSR

conductor and associated switchgear km 19

New 11kV OH lines in the Mt Kenya region, in 75mm2 ACSR conductor and associated switchgear

63

New LV OH lines in the Mt Kenya region, in 50mm2 AA conductor.

117

Works: MtKE-300 Civil works Lot MtKE-301 Erection and stringing Lot

5.1.3. Nairobi A Region

Item Nairobi “A” Region Unit Length Equipment/materials: NBIA-200 New 33 kV OH lines in the Nairobi A region, in 75mm2 ACSR

conductor and associated switchgear km 13

New 11kV OH lines in the Nairobi A region, in 75mm2 ACSR conductor and associated switchgear

37

New LV OH lines in the Nairobi A region, in 50mm2 AA conductor.

104

Works: NBIA-300 Civil works Lot NBIA-301 Erection and stringing Lot

5.1.4. Nairobi B Region and Coast Region

Item Nairobi “B” and Coast Region Unit Length Equipment/materials: NBIBC-200

New 33 kV OH lines in the Nairobi B and Coast region, in 75mm2 ACSR conductor and associated switchgear

km 29

New 11kV OH lines in the Nairobi Nairobi B and Coast region, in 75mm2 ACSR conductor and associated switchgear

58

New LV OH lines in the Nairobi Nairobi B and Coast region, in 50mm2 AA conductor

157

Kenya Power and Lighting Company VI 5.2 - 3 Contract Insert No Distribution Reinforcement and Upgrade Technical Specifications and Drawings

2 - 5.0 Scope of work SOW-lines.doc Oct 2010 kplc

Works: NBIBC-300 Civil works Lot

NBIBC-301 Erection and stringing Lot

5.2. Optional Works Summary

Because of limited ‘wayleave’ trace, KPLC accepts the line designs that combine lines of different voltage levels on the same support structure as long as the correct conductor/ equipment clearances are observed. The following are the interpretations of the work descriptions as described in the list below. Construction of a new line on the same ‘’wayleave trace’’ with an existing line shall mean: Supply of new conductor and all the necessary hardware and support structures required to have the line on the same wayleave trace with existing line. Any recovered material shall be handed over to the KPLC at locations to be informed. ‘Reconductoring’: The term "reconductoring" in this scope of works shall mean supply of new conductors, new hardware/fittings and new poles as well as installation of this in the existing line routes. It also includes moving all equipment, such as distribution transformers, autoreclosers, switches and links, capacitor banks etc, attached to the present poles over to the new poles. All existing poles, conductors and hardware/fittings shall be recovered and handed over to the KPLC at locations to be informed. The complete scope under paragraph 5.2, are optional, and may be included partially or completely as allowed by the Employer’s budget.

5.2.1. Mt. Kenya

Mtkenya 701 Construction of 11KV Line on the wayleave of 33KV Line

10KM

Mtkenya 702  Construction of 0.415KV Line on the wayleave of 33KV Line 5KM

Mtkenya 703 Construction of 33KV Line on thewayleave of 0.415KV Line

12KM

Mtkenya 704 Construction of 0.415KV Line on the wayleave of 66KV Line 0KM

Mtkenya 705  Construction of 0.415KV Line on the wayleave of 11KV Line 7KM Mtkenya 706  Construction of 11KV Line on the wayleave of 0.415KV Line 3KM Mtkenya 707  Construction of 11KV Line on the wayleave of 66KV Line 3KM Mtkenya 708  Construction of 33KV Line on the wayleave of 11KV Line 3KM Mtkenya 709  Reconductoring of 11KV Line 4KM Mtkenya 710  Reconductoring of 33KV Line 3KM

Kenya Power and Lighting Company VI 5.2 - 4 Contract Insert No Distribution Reinforcement and Upgrade Technical Specifications and Drawings

2 - 5.0 Scope of work SOW-lines.doc Oct 2010 kplc

5.2.2. Nairobi A

NBI  A 701  Construction of 11KV Line on the wayleave of 33KV Line 6KM NBI  A 702 

Construction of 0.415KV Line on the wayleave of 66KV Line 4KM

NBI  A 703  Construction of 0.415KV Line on the wayleave of 11KV Line 7KM NBI  A 704  Construction of 11KV Line on the wayleave of 0.415KV Line 3KM NBI  A 705  Construction of 11KV Line on the wayleave of 66KV Line 3KM NBI  A 706  Construction of 33KV Line on the wayleave of 11KV Line 3KM NBI  A 707  Reconductoring of 11KV Line 4KM

5.2.3. Nairobi B and Coast

5.3.4. West Kenya

GSWKen 701  Construction of 11KV Line on the wayleave of 33KV Line 3KM GSWKen 702  Construction of 0.415KV Line on the wayleave of 33KV Line 5KM GSWKen 703  Construction of 33KV Line on thewayleave of 0.415KV Line 12KM GSWKen 704  Construction of 0.415KV Line on the wayleave of 66KV Line 5KM GSWKen 705  Construction of 0.415KV Line on the wayleave of 11KV Line 7KM GSWKen 706  Construction of 11KV Line on the wayleave of 0.415KV Line 5KM GSWKen 707  Construction of 11KV Line on the wayleave of 66KV Line 5KM GSWKen 708  Construction of 33KV Line on the wayleave of 11KV Line 3KM

NBI Coast 701  Construction of 11KV Line on the wayleave of 33KV Line 3KM

NBI Coast 702  Construction of 0.415KV Line on the wayleave of 33KV Line 5KM

NBI Coast 703 Construction of 33KV Line on thewayleave of 0.415KV Line

12KM

NBI Coast 704 Construction of 0.415KV Line on the wayleave of 66KV Line 5KM

NBI Coast 705  Construction of 0.415KV Line on the wayleave of 11KV Line 7KM

NBI Coast 706  Construction of 11KV Line on the wayleave of 0.415KV Line 5KM

NBI Coast 707  Construction of 11KV Line on the wayleave of 66KV Line 5KM

NBI Coast 708  Construction of 33KV Line on the wayleave of 11KV Line 3KM

NBI Coast 709  Reconductoring of 11KV Line 4KM

NBI Coast 710  Reconductoring of 33KV Line 3KM

Kenya Power and Lighting Company VI 5.2 - 5 Contract Insert No Distribution Reinforcement and Upgrade Technical Specifications and Drawings

2 - 5.0 Scope of work SOW-lines.doc Oct 2010 kplc

GSWKen 709  Reconductoring of 11KV Line 4KM GSWKen 710  Reconductoring of 33KV Line 3KM

SCOPE OF WORK – DISTRIBUTION SUBSTATIONS

VI - i

2 - 6.0 Scope of Works Distribution Substations .doc FEB 2009 kplc

TABLE OF CONTENTS

6.  SCOPE OF WORK – DISTRIBUTION SUBSTATIONS ..................................................................... 1 

6.2  GENERAL ....................................................................................................................................... 1 6.3  LOT 1: WESTERN REGION ............................................................................................................. 2 6.4  LOT 2: MT KENYA REGION ............................................................................................................ 2 6.5  LOT 3: NAIROBI A .......................................................................................................................... 2 6.6  LOT 4: NAIROBI B AND COAST ....................................................................................................... 2 

Kenya Power and Lighting Company VI 6 - 1 Contract VI Distribution Reinforcement and Upgrade Technical Specifications and Drawings

2 - 6.0 Scope of Works Distribution Substations .doc FEB 2009 kplc

6. SCOPE OF WORK – Distribution Substations

6.2 General

The Bidder shall examine the scope of works in this section in close connection with the other documents and particulars forming these Bidding Documents. Special attention shall be paid to General Specifications and Particular Technical Specifications, in which the general technical requirements are specified. The drawings enclosed in are for bidding purposes only. If the Specifications and/or Drawings do not contain particulars of materials or goods, which are necessary for the proper and safe completion, operation, and maintenance of the equipment in question, all such materials shall be deemed to be included in the supply. In the event of any conflict between the Drawings and the Specifications, the latter shall prevail. In the event of any conflict between scaled dimensions and figures on the Drawings, the figures shall prevail. Should the Bidder find discrepancies in or omissions from these Specifications or from the other Documents, or should he be in doubt as to their meaning, he should immediately contact the Project Manager for interpretation, clarification or correction thereof before submitting his Bid. Such action shall, however, in no case be considered as a cause for altering the closing date of the Bid. The scope of work for equipment shall cover engineering design, manufacture, testing before shipment and packing sea worthy or otherwise as required, delivery CIP site, of all equipment as specified in the preceding chapters. The contractor shall be responsible for transport, erection and commissioning as well as having the full responsibility for civil works including design and construction of transformer support structures. Equipment that is to be dismantled and removed from existing substations is to be recovered by the Contractor and deposited in the nearest KPLC Depot. The recovered equipment is to be received by Employer’s representative in the depot.

Kenya Power and Lighting Company VI 6 - 2 Contract VI Distribution Reinforcement and Upgrade Technical Specifications and Drawings

2 - 6.0 Scope of Works Distribution Substations .doc FEB 2009 kplc

6.3 LOT 1: Western Region

i) Design, Supply and installation of Distribution Substations.. The Scope of work entails design, supply and installation of 84No 33KV/415V, 11kV/415V, 33KV/240V and 11KV/240V distribution substations complete with transformers, isolation and associated protection system. .

ii) Design, Supply and Installation (Construction) of MV and LV Lines

6.4 LOT 2: Mt Kenya Region

i) Design, Supply and installation of Distribution Substations.. The Scope of work entails design, supply and installation of 89No 33KV/415V, 11kV/415V,33KV/240V and 11KV/240V distribution substations complete with transformers , isolation and associated protection system.

6.5 LOT 3: Nairobi A

Design, Supply and installation of Distribution Substations. The Scope of work entails design, supply and installation of 82No 33KV/415V, 11kV/415V,33KV/240V and 11KV/240V, distribution substations complete with transformers , isolation and associated protection system.

6.6 LOT 4: Nairobi B and Coast

Design, Supply and installation of Distribution Substations.

The Scope of work entails design, supply and installation of 108No 33KV/415V, 11kV/415V,33KV/240V and 11KV/240V, distribution substations complete with transformers , isolation and associated protection system.

6.7. Optional Works Summary

The Upgrade of distribution Substations shall mean replacement of the support structures and all other hardware/connectors/fittings that is necessary for installation of the new transformer. The complete scope under paragraph 6.7, is optional and may be included partially or completely as allowed by the Employer’s budget.

Kenya Power and Lighting Company VI 6 - 3 Contract VI Distribution Reinforcement and Upgrade Technical Specifications and Drawings

2 - 6.0 Scope of Works Distribution Substations .doc FEB 2009 kplc

6.7.1. Mt Kenya

6.7.2. Nairobi A

NBI A 708  Upgrading of Pole Mounted 3-phase transformers 50KVA to 100KVA 7No

NBI A 709  Upgrading of Pole Mounted 3-phase transformers 100KVA to 200KVA 2No

NBI A 710  Upgrading of Pole Mounted 1-phase 25KVA transformer to 50KVA 1No

6.7.3. Nairobi B and Coast

NBI Coast 711  Upgrading of Pole Mounted 3-phase transformers 50KVA to 100KVA 2No

NBI Coast 712  Upgrading of Pole Mounted 3-phase transformers 100KVA to 200KVA 1No

NBI Coast 713  Upgrading of Pole Mounted 1-phase 25KVA transformer to 50KVA 2No

6.7.4. West Kenya

GSWKen 711  Upgrading of Pole Mounted 3-phase transformers 50KVA to 100KVA 2No

GSWKen 712  Upgrading of Pole Mounted 3-phase transformers 100KVA to 200KVA 1No

GSWKen 713  Upgrading of Pole Mounted 1-phase 25KVA transformer to 50KVA 2No

Mtkenya 711  Upgrading of Pole Mounted 3-phase transformers 50KVA to 100KVA 2No

Mtkenya 712 Upgrading of Pole Mounted 3-phase transformers 100KVA to 200KVA

2No

Mtkenya 713  Upgrading of Pole Mounted 1-phase 25KVA transformer to 50KVA 5No

DRAWINGS - SUBSTATIONS

VI 4.4- i

3 - 7 Contr VI-Section VI-drawings-subst.doc FEB 2009 kplc

TABLE OF CONTENTS

7.  DRAWINGS - SUBSTATIONS ............................................................................................................ 2 

7.1.  Project Locations ...................................................................................................................... 2 7.2.  DRAWING LISTS GENERAL .............................................................................................................. 2 7.3.  DRAWING LIST ................................................................................................................................ 2 (A)  CADASTRAL MAPS SHOWING EXISTING LINES AND TRANSFORMERS. .................................................. 2 

3 - 7 Contr VI-Section VI-drawings-subst.doc FEB 2009 kplc

7. DRAWINGS - SUBSTATIONS

7.1. Project Locations

Map copies indicating the exact project locations will be submitted to successful bidders.

7.2. Drawing Lists General

Sample drawings for selected sites will be submitted to the potential bidders during site visits.

7.3. Drawing list

(a) Cadastral Maps showing existing Lines and transformers.

(b) Typical drawings for overhead line components.

(c) Typical drawings for warning signs and labels.

Kenya Power and Lighting Company VI 4.4 - 1 Contract VI Distribution Reinforcement and Upgrade Technical Specifications and Drawings

3 - 7 Contr VI-Section VI-drawings-subst.doc FEB 2009 kplc

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KPLC CODE 181201

(332mm X 40mm X 6mm Galvanised steel flat) (Note 11/2” X ¼” or 13/4” X 5/16” Hole 11/16”) FIGURE 1. D – IRON (LV Insulator Bracket)

KPLC CODE 188104

(180mm X 40mm X 6mm mild steel flat) FIGURE 2. SHACKLE STRAP (LV Extension Strap)

KPLC CODE 188115 (590mm X 40mm X 6mm)

FIGURE 3A. 11KV FLAT TIE STRAP

KPLC CODE 188111

(580mm X 68mm X 68mm x 6.25mm – MS Angle) –

FIGURE 3B. 11KV ANGLE TIE STRAP

KPLC CODE 188108

(860mm x 50mm x 50mm X 6mm MS angle) (2” X 2” X ¼”)

FIGURE 4. 33KV TIE STRAP

KPLC CODE 188107

(250mm X 75mm X 10mm MS flat) (3” X ¼”)

FIGURE 5. 11KV TERMINAL STRAP

KPLC CODE 188109

(500mm X 76mm X 10mm MS flat) (75mm X 6mm) (3” X ¼”)

FIGURE 6. 33KV TERMINAL STRAP

KPLC CODE

(1730mm X 100mm X ) FIGURE 7. EARTH STOCK KPLC CODE 182911

(1625mm X 70mm X 70mm X 9.5mm MS angle) FIGURE 8A. 11KV CROSS ARM KPLC CODE 182914

(1620mm X 125mm X 76mm X 9.5mm MS angle) (5” X 3” X 3/8”) FIGURE 8B. 11KV TERMINAL CROSS ARM

KPLC CODE 186914

(2400mm X 100mm X 75mm X 9.5mm MS angle) FIGURE 9. 33KV CROSS ARM

KPLC CODE 186925

(2290mm X 100mm X 50mm MS angle) FIGURE 10. FUSE/SOLID LINK CROSS MEMBER CHANNEL

KPLC CODE 186921 FOR TX UP TO 200 KVA KPLC CODE 186922 FOR TX 200 TO 315 KVA

(2290mm X 125mm X 64mm X 6mm MS angle) (2290mm X 100mm X 50mm X 6mm MS angle) FIGURE 11. STEADY INSULATOR. CROSS MEMBER

KPLC CODE 186923

(2290mm X 100mm X 50mm MS angle)

FIGURE 12 TRANSFORMER PLATFORM UP TO 200 KVA

KPLC CODE 186924

(1980mm X 125mm X 64mm X 6mm MS angle) FIGURE 13. TRANSFORMER PLATFORM 315 KVA

KPLC CODE 186924

(840mm X 125mm X 64mm X6mm Channel) ( 64mm X 64mm X 6mm MS angle weld) FIGURE 13B. MOUNTING BRACKETS FOR TRANSFORMER PLATFORM 315 KVA