{79aef4b6-37c8-407a-b061-f5d4f5b2577d} Electrical Wks-technical Specification for Electrical...

7/28/2019 {79aef4b6-37c8-407a-b061-f5d4f5b2577d} Electrical Wks-technical Specification for Electrical Installation

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GENERAL TECHNICAL SPECIFICATIONS (ELECTRICAL)

1.0 The intent of this chapter of the specification is to define the generaltechnical requirements of internal electrical wiring works.

1.1 STANDARDS

The work shall be carried out in conformi ty with this specification, therelevant specifications / code of practice of the Indian StandardsInstitutions, approved drawings and instructions of the Engineer-in-Charge or his authorized representative issued from time to time. Inaddition to the above, all works shall conform to the requirements ofthe following :

a) Indian Electricity Act and Rules.b) Regulations laid down by Chief Electrical Inspector of thestate, power supply authority.c) Relevant Indian Standards and National Electrical Cod e.d) Any other regulation laid down by the local authorities.

1.2 Specification of items / works including definition of terms,measurement, Classification etc. not covered in this specification shallbe governed by the General Specification for Electrical works Part I& II, 2004-05 of APWD.

1.3 EQUIPMENT SPECIFICATIONS

All materials, fittings, applications, accessories to be supplied by theContractor shall be of best quality and shall conform to the specificationgiven hereunder. The equipment shall be manufactured in accordancewith the current Indian Standards Specification. Samples of allmaterials before being used shall be procured by the Contractor to theEngineer-in-Charge or his authorized representatives. The materialshall be used / installed only after approval by the Engineer -in-Charge.

1.3.1 Switches

All switches for wiring shall be manufactured in accordance withIS:3854 and shall be piano type unless otherwise specified.

1.3.2 Receptacles

Only three pin-type receptacles manufactured in accordance withIS:1293 shall be used with third terminal connected to the earth. Allreceptacles shall be provided with a switch mounted on the sameenclosure. Receptacles shall be of flush mounting type except for therating above 15/16 amps. un less otherwise specified.

1.3.3 Outlet / Switchboard boxes


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Outlet boxes for socket, switches fixtures and regulators etc. shall be ofminimum 18 gauge (for size up to 20 cm x 30 cm) and 16 gauge (forsize above 20 cm x 30 cm) or specified in the schedule of items.Junction / outlet boxes shall be used in roof slab where concealedwiring has been adopted. The junction / outlet / switch boxes shall bepainted with anticorrosive paint before installation. Cover plates shall

be of Formica or approved equivalent with colour to suit the wall. Coverplates shall be fixed by cadmium plated brass screw and suitable c.p.brass cup washers. An earth terminal with stud and washers shall beprovided in each MS box for termination of protective earth conductors.

1.3.4 Conduit and Fittings

Conduits shall be of metallic or non -metallic type as specified :

a) All rigid metallic conduit pipes shall be of steel and be ISI marked.The minimum wall thickness shall be 1.6 mm (16 SWG) up to 32 mmdia and 2 mm (14 SWG) above 32 mm dia. The conduit shall be solid

drawn or reamed by welding and finished with galvanized or stoveenameled surface.

b) All non-metallic conduit pipes and accessories shall be of suitablematerial complying with IS:2509-1973 and IS:3419-1976 for rigidconduits and IS:6946-1973 for flexible conduits. The interior of theconduits shall be smooth and free from obstructions. The rigid pipesshall be ISI marked.The minimum wall thickness of the rigid non -metallic conduits shall be 1.6 mm up to 25 mm dia conduit.

c) No conduit less than 20 mm in diameter shall be used.

d) All metallic conduit accessories shall be only threaded type, pin gripor clamp type accessories are not acceptable.

e) Accessories for non-metallic rigid type of conduits shall be normal lyof grip type.

1.3.5 Casing and Capping

a) Casing and capping shall be of good quality PVC, free from defectslike deformations, unevenness, blisters, cavities, etc.

b) The casing shall be of square or rectangular body with top of theside walls suitable for tightly fitting slide-in type capping with doublegrooving. All surfaces shall have smooth finish inside and outside.

1.3.6 Wires and Cables

a) Wiring cables- Wires shall be PVC insulated 1100 V grade as per IS:1554.- Conductors shall be of stranded copper.


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- The smallest size of conductor for lighting circuits shall have anominal cross-sectional area of not less than 1.5 sq.mm, whileminimum size of power wiring shall be 2.5 sq.mm.- All wires shall be ISI marked.

b) Flexible cable

- Flexible cables shall be PVC insulated having a minimum sizeof 14/0.0193 mm.- All flexible wires shall be mechanically protected by toughrubber or PVC sheath.

c) Underground cables

- Power cables:

Power cables for use in 415 V system shall be of 1100 V grade,aluminium stranded conductor, PVC insulated, PVC sheathedsingle wire armoured and overall PVC sheathed. All power

cables for 11kV and 33 kV shall be aluminium conductor, XLPEinsulated, screened, PVC bedded galvanized steel flat armoured(non-magnetic material in case of single core cable) and PVCsheathed cable. All 415 V cables shall conform to IS:1554 andHT cables shall conform to IS:7098. Unarmoured cables will beused only where specified.

- Control cables : Control of cables shall be 1100 V gr ade, 2.5sq.mm copper conductor, PVC insulated, PVC sheathed, singlewire armoured with overall PVC sheathed as per IS:1554.

d) Communication cables :

Communication cable shall comprise 1 pair unarmoured, 2 -pair, 5-pairand multipair armoured cable of size as specified in the schedule.Minimum conductor size shall be 0.5 mm dia for telephone system and0.71 for other communication system.

1.3.7 Switchgear and Control Geara) General

- All items of switchgears and distribution boards shall be metalclad type except those forming part of cubicle type switchboards.

- The types, ratings and make of the switchgear and protectivegear shall be as specified in this specification and the scheduleof works.

- RCCBs (ELCBs) shall conform to the ratings specifie d in theschedule of works.


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- Each distribution boards shall have one independent andseparate terminal block each for the neutral and the earthconductors.

- Each distribution boards shall be provided with earthingterminals for body Earthing one for single phase and two for

three-phase.

- All DBs (single phase or three phase) shall be of 4, 6, 8 or 12ways as specified. Number of ways as stated above, in case ofthree phase DB shall mean ways per phase.

- Bus-bars used shall be of electrolyte copper of appropriate size.

b) MCB Type Distribution Board (MCBDB)

- MCB type distribution boards shall be either single phase or 3 -phase type horizontal or vertical, depending upon whether

outgoing circuits are single phase or 3 phased / 1 phase.

- All MCBDBs shall have provision for accommodating MCBtype isolators and RCCB (ELCB) at incoming in single pole ormultiple configuration.

- All MCBDBs unless specifically mentioned and/or havingdifferent circuitconfiguration than the standard manufacturingrange shall be factory fabricated and completely pre -wired andready for installation at site.

- MCBDBs shall be fabricated out of 1.6 mm thick sheet steelwith stove enameled paint finish and shall be wall mounted typeif not specified otherwise.

- The boards shall have adequate provision for entry of incomingand outgoing cables / wires through knockout holes with orwithout detachable plates.

c) Medium Voltage Switchboard

Medium voltage switchboards or MV switchgear panels shall be as perthe schedule of items and as per the following specific requirements in

addition to the general requirements as per the latest editions ofapplicable Indian Standards.

The switchboard shall be free -standing, metal enclosed,compartmentalised, modular type, dust and vermin proof suitable forindoor installation. Switchgear enclosure shall provide degree ofprotection not less than IP-31 as per IS: 2147. The switchgear shall beassembled out of vertical panels of uniform height not exceeding 2450


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mm. The maximum height of the operating handle / switches shall notexceed 1800 mm and minimum height not below 300 mm.

The switchgear shall be designed to ensure maximum safety duringoperation, inspection, connection of cables, relocation of outgoingcircuits and maintenance with the energised bus-bar system and

without taking any special precautions. The switchgear shall permitmaximum interchangeability and shall be extensible on either side.

The switchboard shall be sheet steel clad with the frame fabricated outof 14 SWG cold rolled sheet steel and doors / covers out of 15 SWGcold rolled sheet steel;having integral base frame for each verticalpanel. All hardware shall be corrosion resistant. All joints andconnections of the panel members shall be made of galvanised, zincpassivated or cadmium plated high quality steel bolts, nuts andwashers, secured against loosening.

The switchgear shall be suitable for bottom cable entry. Provision for

incoming connection through busduct shall be made as perrequirement of the specificat ion and schedule of rates.

Individual circuit breakers, switch fuse units, MCCBs, bus -bars, cabletermination compartment shall be housed in separate enclosedcompartments separated from each other by metallic barriers.

Circuit breaker panel shall be in single front execution only. Not morethan two breaker cubicles shall be housed in single vertical panelexcept for the incomer and bus-coupler, which shall each be housed inindependent vertical panels. Motor starters, switch fuse units, MCCBsshall be in suitable arrangement in single or double front as specified inthe schedule of items. All auxiliary devices for control, indications,measurement and protection such as push-button, control and selectorswitches, indicating lamp, metering instruments prot ective relaysexcept bimetallic relays shall be mounted on the front side of therespective compartment Components requiring frequent inspectionduring operation shall be easily accessible.

Main bus-bars shall be of high conductivity aluminium or electrol yticcopper as specified having uniform current rating throughout theirlength. Horizontal and vertical bus-bars shall be sized depending uponthe maximum expected current and to limit the maximum operating

temperature at specified design ambient temperature to 85C fornormal operating condition and to 200C for short -circuit conditionconsidering installation in a poorly ventilated area.

Adequately sized auxiliary copper / aluminium bus -bars runninghorizontally in a separate enclosure shall be provided for space heaters,control supply and metering requirements. Necessary tee -offconnections shall be used for distributing auxiliary supply to eachvertical panel.


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All bus-bars shall be colour coded and designed to withstand specifiedshort circuit currents for one second.

Aluminium earth bus with 300 sq.mm minimum size or equivalentcopper bus shall be provided throughout the length of the switchboard

with provision for interconnecting to earth grid. All non -current carryingmetallic parts of the mounted equipment shall be earthed. Door andmovable parts shall be earthed using flexible copper connections.

Inside the switchboards the wiring for power, control, signalingprotection and instrument circuits shall be done with PVC insulatedcopper, conductors having 660 / 1100 V grade insulation. Minimumsize of the control wire shall be 1.5 sq.mm copper for circuits havingfuse rating 10 Amps. or less. For control circuit with higher fuse ratingmin 2.5 sq.mm copper conductor shall be used.

Elmex type terminals shall be acceptable for wiring upto 10 sq.mm

size and for conductors larger than 10 mm2, bolt type terminals withcrimping lugs shall be provided. Each wire shall be terminated at aseparate terminal. A minimum of 10% spare terminal shall be providedfor all CT terminals. For modules rated above 100 amps., preferablycopper strip connection shall be used.

The air circuit breakers shall be fully drawout type, Circuit breakerpanel shall have three distinct positions : viz service, test, full outposition complete with necessary safety interlocks, scraping, earthconnection, shutters, safety barriers and suitable guides for easymovement of the trolley. Access to the cables shall be from the rearside after opening the door of the separate cablin g compartment.Circuit breakers shall be trip free type having antipumping features andelectrically operated mechanism suitable for control supply specified inthe schedule of items/ specification. Circuit breaker trip coils shall berated for satisfactory operation with 50% to 110% of rated voltage andthe closing coil shall be rated for 85% to 110% of the rated voltage.

All switch fuse units shall be load break, heavy duty, air break type(double break) with the operating handle mounted on compartmentdoor, complete with necessary interlocking mechanism.

All fuses shall be non-deteriorating HRC cartridge, pressure fitting link

type.

All relays shall be back connected, drawout type suitable for flushmounting and fitting with dust tight covers along wit h hand reset typebuilt in flag indication.

Current transformers for metering shall have an accuracy class 1.0 andinstrument accuracy class 5 P and accuracy limit factor greater than10.


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All indicating instruments shall be flush mounting type and of 96 x 96mm squarepattern, except the digital instruments. Digital instruments ifrequired shall be as per schedule of items / specific technicalspecifications.

All control / selector switches shall be rotary back connected typehaving a cam operated contact mechanism.

1.3.8 Miniature Circuit Breaker

a) Miniature circuit breakers shall be of approved make and rating asspecified.

b) L series MCBs shall be used only for normal lighting circuits.

c) G series MCBs shall be used for all motor loads, air conditioners,halogen and other discharge lamps and all power circuits.d) All MCBs shall be of 9 KA breaking capacity, unless specifically

mentioned otherwise in the schedule of items.

1.3.9 Moulded Case Circuit Breaker

a) Moulded case circuit breakers shall be of approved make.Adjustable type MCCBs shall be used unless otherwise specified in theschedule of items /specific technical specification.

b) Current rating and the short circuit rating of the MCCBs shall be asper

schedule of items.

1.3.10 Medium Voltage Bus-ducta) Enclosure

The enclosure of the medium voltage bus -duct shall be of 14 SWGsheet steel with removable cover in one side and shall be totallyenclosed, dust and vermin proof. The cover shall be fitted with dustpreventing gaskets, secured with sufficient number of cadmium platediron screws to ensure that the cover is dust tight. Suitable openingsshall be provided for cable / conduit entries as required. The enclosureshall be pained with one coat of primer paint after cleaning the surfaceand after dressing and degreasing. Two coats of finish paint shall

thereafter be applied by spray painting process. This shall be done inthe works before bringing the materials to site.b) Bus-bars and Supports

Bus-bars shall be made of electric grade copper conforming to relevantIndian Standards and shall be supported on robust non -hygroscopicinsulators at regular intervals to withstand the specified short circuitcurrent. Bus-bars shall be suitably insulated with PVC sleeves / tapes.

An aluminium / copper earth bus of suitable size to be specified shall


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be run along the bus-duct having necessary provision for connection tothe earthing network.

1.4 Building Wiring System

Wiring system to be adopted shall be as specified under specified

technical requirements and shall conform to the general requirementsas specified hereunder.

1.4.1 Conduit Wiring System

A. General

a) Surface or concealed conduit wiring system with ERW or GI orpolyethene conduit as specified shall be adopted.

b) Conduit work whether surface or concealed shall be completedbefore the cables are drawn in.

c) Conduit pipes shall be jointed by means of screwed couplers andscrewed accessories (in case of metallic conduits) only. In case of non -metallic conduits joints shall be properly sealed.

d) All bends in the wiring system shall be done either by bending thepipes neatly without any crack or by inserting suitable accessories likebends, elbows or similar fittings. Radius of bends in conduit pipes shallnot be less than 7.5 cm.

e) All metallic parts of conduits and accessories in recessed wiringsystem shall be painted with anticorrosive paint before their installation.

f) In all conduit wiring system, a protective earth conductor as specifiedshall be drawn inside the conduit to provide for earthing of non currentcarrying metallic parts of the installation. Earth wires shall beterminated in the switch boxes and / or the earth terminal blocks at theDBs. In case, the earth wire specified is of large size which may not bepossible to be carried inside the conduits may also be laid external tothe conduit subject to approval of the Engineer -in-Charge. In case ofthe metallic conduits entire conduit system shall be electrically andmechanically continuous.

g) Maximum number of PVC insulated 650 / 1100 V grade cables thatcan be drawn in one conduit is given size wise in Table -1, which shallnot be exceeded. Conduit sizes shall be selected accordingly.

h) When crossing through expansion joints in buildings, the conduitsections across the joint may be through flexible conduits of the samesize as the rigid conduit.


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B. Additional Requirements for Surface Conduit Wiring System

a) Conduit pipes shall be fixed by heavy gauge non -metallic saddles incase of non-metallic conduits and 24 gauge (up to 25 mm dia) / 20gauge (for larger dia) steel saddles in case of metallic conduit system.

b) Saddles shall be fixed at an interval not more than 60 cm in case ofnonmetallic conduits and not more than 1 m in case of metallic con duit.However, on either side of the couplers or bends or similar fittings,saddles shall be fixed at a distance of 30 cm (for metallic conduit) / 15cm (for non-metallic conduit) from the surface of such fittings.

c) Where conduits are required to be lai d along the trusses / joist etc.,the same shall be secured by means of saddles / girder clips etc. Asper instruction /approval of the Engineer-in-Charge.

d) In all the cases when conduits are laid in masonry / concrete work,saddles shall be properly secured by inserting polyethylene plugs

approved by the Engineer-in-Charge.

C. Additional Requirements for Recessed Conduit Wiring System

a) Fixing of Conduits in RCC works.

i) The conduit pipes shall be laid in position and firmly secured to thesteel reinforcement bars by steel binding wires before concreting isdone.ii) Instead of using standard bends or elbows the conduit itself shouldbe bent in long radius to facilitate easy drawing of conductors.iii) Inspection and junction boxes should be suitabl y located to avoidlong conduit runs and such boxes shall be properly identified to avoidunnecessary chipping of the RCC slab subsequently to locate theseboxes.iv) Special care shall be taken in laying the conduits and during theconcreting work to avoid damage to the conduits.

b) Laying of conduit in wall

i) Conduits shall be laid in the wall before plastering work in neatlymade chase.ii) The conduits shall be secured by means of staples / saddles / J -

hooks at intervals not more than 60 cm.iii) The joints between the conduits and the switch boards / distributionboards shall be properly sealed.


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TABLE 1

MAXIMUM PERMISSIBLE NUMBER OF 650 / 1100 V GRADECABLES THAT CAN BE DRAWN INTO RIGID CONDUITS

1.4.2 Casing Wiring SystemCasing wiring system may be adopted as specified by using metallic or

PVC casing and capping. All specifications for casing wiring sy stemshall be as per the General Specifications for Electrical Works (Part -Iinternal), 2004-05 of APWD.


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1.4.3 Earthing

A) Materials

i) Earth electrodes shall be any of the following type as

specified.

a) Pipe / rod earth electrodeb) Plate earth electrodec) Strip electrode

Pipe electrode shall be of G.I. heavy class with minimum 38 mm diaand 2.5 m long as per details shown in the drawing. Rod electrodesmay be of steel or copper of 2.5 m minimum length. Minimum dia shallbe 16 mm in case of steel and 12.5 mm in case of copper. Theelectrodes shall have no joints.

Plate electrodes may be of galvanized iron / steel or copper. In case ofgalvanized iron or steel thickness shall not be less than 6.30 mm,which in case of copper plate electrodes, thickness shall not be lessthan 3.15 mm. Minimum size of plate electrodes for both GI and coppershall be 60 cm x 60 cm. Strip electrodes shall not be smaller than 25mm x 1.6 mm if of copper and 25 mm x 4 mm if of galvanized iron. Ifround conductors are used as earth electrodes, their cross sectionalarea shall not be smaller than 3.0 mm2 if of copper and 6 mm2 if of G.I.

ii) The main earthing conductor (from earth electrode to the mainswitch board or earth bus) shall be of G.I. or copper as specifi ed.The sizes shall also be as per specification. However, in no casethe size of the main earthing conductor be less than

a) 5 mm dia (6 SWG) for G.I. or 4 mm dia (8 SWG) forcopper wire.

b) 25 mm x 4 mm in case of G.I. strip.

c) 20 mm x 3 mm in case of copper strips.

iii) The earth continuity or loop earthing conductor shall be ofcopper, aluminium or G.I. as specified. The minimum size of the

earth continuity conductor shall be as follows :a) 2 mm dia (14 SWG) in case of bare copper (1.5 mm2in case of insulated)

b) 2.24 mm dia (13 SWG) in case of bare aluminium 2.5mm2 in case of insulated)

c) 2.5 mm dia (12 SWG) in case of G.I.


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B) Installation

i) Electrodes shall be as far as practicable, be embedded belowpermanent moisture level to a depth of at least 1.25 m. If rock isencountered, the depth of burial may be less than the specified value,

subject to approval of the Engineer -in-Charge. In such case, theelectrodes may be buried inclined to the vertical with inclination notmorethan 30 from the vertical.ii) In case where more than one electrode has been specified, thedistance between two electrodes shall preferably be not less than twicethe length of the electrode.iii) Plate electrodes shall be buried such that its top edge is at a depthnot less than 1.5 m from the surface of the ground.iv) Earth electrode normally shall not be located closer than 1.5 m fromany building and should not be installed in proximity to a metal fence toavoid the possibility of the fence becoming live due to v oltage gradient

of the electrodes. If the metal fence is unavoidable, it should beearthed.v) The strip electrodes shall be buried in trenches or ditches not lessthan 0.5 m deep and the length of the buried conductor shall besufficient to give the required earth resistance. It shall, however, be notless than 15 m.

1.4.4 Installation of Fixtures / Fan

i) Fixtures shall be firmly supported from the structures, support clamps,etc., may be bolted or welded to the existing steelwork or metal inserts.In case of concrete structures, where metal inserts are not available,fixtures will be fixed to or supported from concrete surfaces with thehelp of anchor fastener. In such cases special care shall be taken tosee that anchoring is firm. In case of concrete structures where metalinserts are not available, fixtures having smaller weights shall besupported by nylon sleeve / steel sleeve anchors inserting in neatlydrilled holes or appropriate size as shown in the typical drawing. Nylonor steel sleeve / rawl plugs should be inserted by making 1.5 deep,0.25 dia, cylindrical hole using electric hand drill. In no case woodenplugs shall be allowed. This procedure shall be followed for fitting alltypes of electrical fittings, switchboard, conduits etc. on surface in wall /ceilings.

ii) Fan clamps shall be of suitable design according to the nature ofconstruction of the ceiling on which these clamps are to be filled. In allcases the fan clamps shall be fabricated from new metal of suitablesizes and they shall be as close fitting as possible. Fan clamps forreinforced concrete roof shall be buried with the casting and due careshall be taken that they shall serve the purpose. Fan clamps for woodbeams shall be of suitable flat iron fixed on two sides of the be am and


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according to the size and section of the beam one or two mild steelbolts passing through thebeam shall hold both flat iron together. Fan clamps for steel joints shallbe fabricated from flat iron to fit rigidly to the bottom flange of the beam.Care shall be taken during fabrication that the metal does not crackwhile hammering to shape. In cases where false ceiling exists, the fans

shall be firmly connected to the structure / ceiling and not to the falseceiling.

1.4.5 Lightning Protection

i) Lightning protection shall be done in accordance with the tenderspecification,IS:2309-1989 and National Electrical Code.ii) The materials for the air-termination, down conductors etc. For thelightning protective system shall be copper or G.I., as per spe cification.Recommended shape and minimum sizes of the conductors for useabove ground and below are given below:

Shape and minimum size of conductors for use above ground :

Materials and shape Minimum size

Round copper wire 6 mm dia

Stranded copper wire 50 mm2 (or 7 / 3.0 mm dia)

Copper strip 20 x 3 mm

Round galvanised iron 8 mm dia

Galvanised iron strip 20 x 3 mm

Shape and minimum size of conductors for use below ground:

Round copper wire 8mm dia

Copper strip 32X6Mm

Round galvanised iron wire 10mm dia

Galvanised iron strip 32 x 6 mm

iii) Air Termination

1. Air termination network may consist of vertical, horizontal or acombination of both vertical and horizontal conductors.

2. Vertical conductors shall project at least 30 cm above the object andshall have one point.


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3. Horizontal air termination shall be so interconnected that no part ofthe roof is more than 9 m away from the nearest horizontal conductors.

4. Horizontal air terminations should be laid down the contours such asridges, parapets and edges of flat roofs and where necessary over flatsurfaces in such a way as to join each air termination to the rest and

should themselves from closed network.

5. All metallic finials, chimneys, ducts, vent pipes, railings, gutters andthe like,on or above the main surface of the roof of the structure shallbe bonded to and form part of, the air termination network. If portions ofa structure vary considerably in height any necessary air termination ofair termination network of the lower portions, in addition to their ownconductors be bonded to the down conductor s of the taller portions.

6. All air terminals shall be effectively secured against overturningeither byattachment to the object to be protected or by means ofsubstantial braces andfixings which shall be permanently and rigidly

attached to the building.

iv) Down Conductors

1. The number and spacing of the down conductors shall be as per thetender specification as directed by the Engineer -in-Charge. However,there shall be minimum 2 down conductors for structures up to 400sq.m area and one extra down conductor for every additional 300 sq.mor part thereof.

2. Down conductors should be distributed round the outside walls ofthe structure. They shall preferably be run along the corners and otherprojections. Lift shafts shall not be used for fixing down conductors.

3. Down conductors shall be laid in such a way that they follow themost direct path possible between the air termination and the earthtermination, avoiding sharp bends, upturns and kinks. Joints shall asfar as possible be avoided in down conductors. Adequate protectionmay be provided to the conductors against mechanical damage. Metalpipes should not be used as protection for conductors.

4. Metal pipes leading rain water from the roof to the ground may beconnected to the down conductors. Such connections should have

disconnecting joints for testing purpose.

5. Any extended metal running vertically through the structure shouldbe bonded to the lightning conductor at the top and the bottom unlessthe clearances are in accordance with IS: 2309-1989.

6.Where the provision of suitable external routes for down conductorsis impracticable or inadvisable, as in buildings of cantilever construction,from the first floor upwards, down conductors may be used in an air


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space provided by a nonmetallic, non-combustible internal duct. Anycovered recess not smaller than 75 x 15 mm or any vertical serviceduct running the full height of the building may be used for this purpose,provided it does not contain an unarmored or non-metal sheathedcable.

v) Joints and bonds

Joints: The lightning protective system shall have as few joints in it asnecessary. In the down conductors below ground level these shall bemechanically and electrically effective and shall be so made as toexclude moisture completely. The joints may be clamped, screwed,bolted, crimped, reverted or welded. With overlapping joints the lengthof the overlap should not be less than 20 mm for all types ofconductors. Contact surfaces should first be cleaned and then inhibitedfrom oxidation with suitable non-corrosive compound. Joints ofdissimilar metal should be suitably protected against bimetallic actionand corrosion.

In general, joints for strips shall be tinned, soldered, welded or brazedand at least double riverted. Clamped or bolted joints shall only beused on test points or on bonds to existing metal, but joints shall onlybe of the clamped or screwed type.

b) Bonds : External metal on or forming part of a structure may have todischarge the full lightning current. Therefore, the bond to the lightningprotective system shall have a cross-sectional area not less than thatemployed for the main conductors. On the other hand, internal metal isnot so vulnerable and its associated bonds are at most only likely tocarry a portion of the total lightning current, apart from their function ofequalising potential. These latter bonds may, therefore, be smaller incross-sectional area than those used for the main conductors. All thebonds should be suitably protected against corrosion. Bonds shall beas short as possible.

vi) Testing Points

Each down conductor shall be provided with a testing point in aposition convenient for testing but inaccessible for interference. Noconnection, other than one direct to an earth electrode, shall be madebelow a testing point. Testing points shall be phosphor bronze,

gunmetal, copper or any other suitable material

vii) Earth Terminations

1. Each down conductor shall have an independent earth termination. Itshould be capable of isolation for testing purposes. Suitable location forthe earth termination shall be selected after testing and assessing thespecific receptivity of the soil and with due regard to reliability of thesub-soil water to ensure minimum soil moistness.


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2. Water pipe system should not be bonded to the earth terminationsystem. However, if adequate clearance between the two cannot beobtained, they may be effectively bonded and the bonds should becapable of isolation and testing. The gas pipes, however, should in nocase be bonded to the earth termination system.

3. It is recommended that all earth terminations should beinterconnected. Common earthling, besides equalizing the voltage atvarious earth terminations also minimises any risk to it of mechanicaldamage.

viii) Fasteners

Conductors shall be securely attached to the building or other object tobe protected by fasteners which shall be substantial in construction, notsubject to breakage and shall be made of galvanised steel or other

suitable material. If fasteners are made of steel, they should begalvanised to protect them against corrosion. If they are made of anyother material suitable precautions should be taken to avoid corrosion.Some samples of fasteners are shown in IS:2309 -1969.

ix) Earth Resistance

Each earth termination should have a resistance in ohms to earth notexceeding numerically the product of 10 and the number of earthterminations to be provided. The whole of the lightning protectivesystem should have a combined resistance to earth not exceeding 10ohms before any bonding has been effected to metal in or on thestructure or to surface below ground.

1.4.6 Testing of Wiring Installation

After completion of wiring a general inspection is carried out by theEngineer-in- Charge or his representative to verify that the provisionsof the specification and Indian Electricity Rules, 1956 have beencomplied with. After inspection, the following tests shall be carried outbefore an installation or an addition to the existing installation is put intoservice.The following tests shall be done

a) The insulation resistance shall be measured by applying betweenearth and the whole system of conductor or any section thereof with allfuses in place and all switches closed and except in earthed concentricwiring, all lamps in position or both poles of installation otherwiseelectrically connected together, a DC voltage of notless than twice theworking voltage, provided that it does not exceed 500 volts for mediumvoltage circuits. Where the supply is derived from the e-wire (AC or DC)or polyphone system the neutral pole of which is connected to earth


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either direct orthrough added resistance, the working voltage shall bedeemed to be that which ismaintained between the outer or phaseconductor and the neutral.b) The insulation resistance in mega ohms of an installation measuredas in (a) shall be not less than 50 divided by the number of points onthe circuit, provided that the whole installation need not be required to

have an insulation resistance greater than 1 M ohm.

c) Control rheostats, heating and power appliances and electric signs,may, if desired, be disconnected from the circuit during the test, but inthat event the insulation resistance between the case or framework,and all live parts of each rheostat, appliance and sign shall be not lessthan that specified in the relevant Indian Standard specification orwhere there is no such specification shall be not less than 0.5 M ohm.

d) The insulation resistance shall also be measured between allconductors connected to one pole or phase conductor of the supplyand all the conductors connected to the middle wire to the neutral on to

the other pole of phase conductors of the supply. Such a test shall bemade after removing all metallic connections between the two poles ofthe installation and in these circumstances the insulation resistancebetween conductors of the installation shall be not less than thatspecified in (b).

e) On completion of an electrical installation (or an extension to aninstallation) certificate shall be furnished by the Contractor,countersigned by the certified supervisor under whose directsupervision the installation was carried out. This certificate shall be in aprescribed form as required by the local electric supply authority. Inaddition to this a completion certificate, as enclosed under Appendix I.Earthing

For checking the efficiency of earthling the following tests arerecommended.

a) The earth resistance of each electrode is measured.

b) The earth resistance of earthling grid is measured.

c) All electrodes are connected to the grid and the earth resistance ofthe entire earthing system is measured.

These tests shall preferably be done during the summer months.


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1.5 Cable Laying

1.5.1 Route

i) Before the cable laying work is undertaken, the route layout of thecable shall be submitted to the Engineer -in-Charge and the work shall

be undertaken only after approval of the route layout.ii) a) Whenever cables of different voltages are laid following pointsshall be noted while laying along well demarcated or established roads,the LV / MV cables shall be laid further from the kerb line than HVcables.

b) Cables of different voltages and also power and control cables shallbe kept in different trenches with adequate separ ation. Where availablespace is restricted such that this requirement cannot be met, LV / MVcables shall be laid above HV cables.

c) Where cables cross one another, the cable of higher voltage shall be

laid at a lower level than the cable of lower voltag e.

iii) Proximity to communication cables.

Power and communication cables shall be as far as possible crosseach other at right angels. The horizontal and vertical clearancebetween them shall not be less than 60 cm.

1.5.2 Methods of Laying

The cables shall be laid direct in ground, pipe, closed or open ducts,cable trays or on surface of wall etc. The method(s) of laying requiredshall be specified in the tender / schedule of work.

1.5.3 Laying direct in ground

i) This method shall be adopted where specified in the schedule ofworks. Normally this method shall be adopted when the cable route isthrough open ground, along roads, lanes, etc. and where no frequentexcavations are likely to be encountered and where re-excavation iseasily possible without affecting other services.

ii) Trenching

a) Width and depth of the trench shall be as shown in the drawing.When more than one tier of cables is unavoidable and verticalformation of laying is adopted, the depth of the trench shall beincreased by 30 cm for each additional tier to be formed.b) The trenches shall be excavated in reasonably straight lines.Wherever there is a change in the direction, a suitable curvature shallbe adopted complying with the minimum bending radius specified in


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Table 11. Where gradients and changes in depth are unavoidable,these shall be gradual. The bottom of the trench shall be level and freefrom stones, brick bats etc.

TABLE 2MINIMUM BENDING RADIUS PAPER INSULATED CABLES AND XLPE

CABLESSystem voltage Minimum bending

radius

Single Core MultiCoreArmoured Unmoured

11KV 20D 12D 15D

22KV 25D 15D 20D

33KV 30D 20D 25D

D is the overall diameter of the cable.

excavation should be done by suitable means manual or mechanical.The excavated soil shall be stacked firmly by the side of the trenchsuch that it may not fall back into the trench.

c) Adequate precautions should be taken not to damage any existingcable(s), pipes or any other such installations in the route duringexcavation. Wherever bricks, tiles or protective covers or bare cablesare encountered, further excavation shall not be carried out without theapproval of the Engineer-in- Charge.

Existing property, if any, exposed during trenching shall be temporarilysupportedadequately as directed by the Engineer -in-Charge. Thetrenching in such cases shall be done in short lengths, necessary pipeslaid for passing cables therein, if required.

If there is any danger of a trench collapsing or endangering adjacent

structures,the sides should be well shored up with sheeting as theexcavation proceeds. Where necessary, these may even be left inplacewhen backfilling the trench.

Excavation through lawns shall be done in consultation with thedepartment concerned.iii) Laying of Cable in Trench


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a) Sand cushioning

The excavated trench shall be provided with a layer of clean, dry sandcushion of not less than 8 cm in depth, before la ying the cables therein.However, sand cushioning may not be provided for MV cables, wherethere is no possibility of any mechanical damage to the cables due to

heavy or shock loading on the soil above if so specified in the tenderdocument and as per approval of the Engineer-in-Charge. Sandcushioning shall however be invariably provided in the case of HVcables.

b) The cable drum shall be properly mounted on jacks, or on a cablewheel at a suitable location, making sure that the spindle, jack etc. arestrong enough to carry the weight of the drum without failure and thatthe spindle is horizontal in the bearings so as to prevent the drumcreeping to one side while rotating.

c) The cable shall be pulled over in rollers in the trench steadily and

uniformly without jerks and strain. The entire cable length shall be faras possible laid off in one stretch. PVC / XLPE cables less than 120sq.mm size may be removed by Flaking i.e. by making one long loopin the reverse direction.

For short runs and sizes up to 50 sq.mm of MV cables, any othersuitable method of direct handling and laying can be adopted withoutstrain or excess bending of the cables.

d) After the cable has been so uncoiled, it shall be lifted slightly overthe rollers beginning from one end by helpers standing about 10 mapart and drawn straight.The cable shall then be lifted off the rollersand laid in a reasonably straight line.

e) Testing before coveringThe cables shall be tested in presence of the Engineer -in-Charge forcontinuity of cores and insulation resistance and the cable length shallbe measured, before closing the trench.

f) Sand covering

Cables laid in trenches in a single tier formation shall have a coveringof dry sand of not less than 17 cm above the base cushion of sand

before the protective covers laid.

In the case of vertical multi-tier formation, after the first cable has beenlaid, a sand cushion of 30 cm shall be provided over the base cushionbefore the second tier is laid. If additional tiers are formed, each of thesubsequent tiers also shall have a sand cushion of 30 cm as statedabove. Cables in the top most tier shall have a final sand covering notless than 17 cm before the protective cover is laid.


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Sand covering as stated above need not be provided for MV cabl eswhere a decision is taken by the Engineer -in-Charge as per sub clause(iii-a) above, but theater tier spacing should be maintained with soft soilinstead of sand between tiers and for covering. Sand cushioning shallhowever be invariably provided in the case of HV cables.

g) Extra loop cable

At the time of original installation, approximately 3 m of surplus cableshall be left on each terminal end of the cable and on each side of theunderground joints. The surplus cable shall be left in the form of a loop.Where there are long runs of cables such loose cable may be left atsuitable intervals as specified by the Engineer-in-Charge.

Where it may not be practically possible to provide separation betweencables when forming loops of a number of cables as in the case ofcable emanating from a substation, measurement shall be made only

to the extent of actual volume of excavation, sand filling etc and paidfor accordingly.

h) Mechanical protection over the covering

Mechanical protection to cables shall be laid over the covering toprovide warning to future excavators of the present of the cable andalso to protect the cable against accidental mechanical damage bypick-axe blows etc. as follows:a) Unless otherwise specified, the cables shall be protected b y secondclass brick of nominal size 22 cm x 11.4 cm x 7 cm or locally availablesize, placed on top of the sand (or, soil as the case may be). The bricksshall be placed breadth wise for the full length of the cable. Wheremore than one cable is to be lai d in the same trench, this protectivecovering shall cove all the cables and projects at least 5 cm over thesides of the end cables.

b) Where bricks are not easily available, or are comparatively costly,there is no objection to use locally available material such as tiles orslates or stone / cement concrete slabs. Where such an alternative isacceptable, the same shall be clearly specified in the tenderspecifications.

iv) Backfilling

a) The trenches shall be then backfilled with excavated earth, free fromstones or other shall edged debris and shall be rammed and watered, ifnecessary in successive layers not exceeding 30 cm depth.

b) Unless otherwise specified, a crown of earth not less than 50 mmand not exceeding 100 mm in the centre and tapering towards thesides of the trench shall be left to allow for subsidence. The crown of


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the earth, however, should not exceed 10 cms so as not to be a hazardto vehicular traffic.

c) The temporary restatements of roadways should be inspected atregular intervals, particularly during wet weather and settlementsshould be made good by further filling as may be required.

d) After the subsidence has ceased, trenches cut through roadways orother paved areas shall be restored to the same density and materialsas the surrounding area and repaved in accordance with the relevantbuildingSpecifications to the satisfaction of the Engineer -in-Charge.

e) Where road berms of lawns have been cut out of necessity, or kerbstones displaced, the same shall be repaired and mad e good, exceptfor turfing /asphalting, to the satisfaction of the Engineer -in-Charge andall the surplus earth or rock shall be removed to places as specified.

v) Laying of single core cables

Three single core cables forming one three phase circuit shal l normallybe held inclose trefoil formation and shall be bound together atintervals of approximately 1m.

The relative position of the three cables shall be changed at each jointat the time of original installation, complete transposition being effectedin every three consecutive cable lengths.

vi) Route markersa) Location: Route markers shall be provided along with the runs ofcable allocations approved by the Engineer-in-Charge and generally atintervals not exceeding 100m. Markers shall also be prov ided toidentify change in the direction of the cable route and locations ofunderground joints.

b) Plate type marker: Route markers shall be made out of 100 mm x 5mm G.I. /aluminium plate welded / bolted on 35 mm x 35 mm x 6 mmangel iron, 60 cmblong. Such plate markers shall be mounted parallelto and at about 0.5 m away from the edge of the trench.

c) CC marker: Alternatively, cement concrete 1:2:4 (1 cement: 2 coarsesand: 4 graded stone aggregate of 20 mm in size) shall be laid flat and

centered over the cable. The concrete markers, unless otherwiseinstructed by the Engineer-in-Charge, shall project over thesurrounding surface so as to make the cable route easily identifiable.d) Inscription: The words IITG-MV / HV CABLE as the case may beshall be inscribed on the marker.


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1.5.4 Laying in Pipes / Closed Ducts

i) In locations such as road crossing, entry in to buildings, pavedareas etc., cables shall be laid in pipes or closed ducts. Stoneware pipes, GI, CI or spun reinforced concrete pipes shall beused for cables as specified in the schedule of works.

ii) Following guide of the pipe fill shall be used for sizing the pipe size:

a) 1 cable in pipe 53% full

b) 2 cables in pipe 31% full

c) 3 or more cables 43% full

d) Multiple cables 40% full

iii) Where cables pass through foundation walls or other underground

structures, the necessary ducts or openings will be provided inadvance for the same. However, should it become necessary to cutholes in existing foundations or structures, the electrical contractorshall determine their location and obtain approval of the Engineer-in-Charge before cutting is done.

iv) At road crossing and other places where cables enter pipe sleevesadequate bed of sand shall be given so that the cables do not slackand get damaged by pipe ends.

v) At road crossings, the top surface of pipes shall be at a minimumdepth of 1 mfrom the pavement level. When pipes are laid cuttingexisting road, care shall be taken so that the soil filled up after layingthe pipes is rammed well in layers with watering as required to ensureproper compaction. A crown of earth not exceeding 10 cm should beleft at the top. After the subsidence has ceased, the top of the filled uptrenches in road ways orother paved areas shall be restored to thesame density and material as the surrounding area in accordance withthe direction of the Engineer-in-Charge (Civil) up to his satisfaction.

vii) All G.I. pipes shall be laid as per layout drawings and siterequirements.Before fabrication of various profiles of pipe byhydraulically operated bending machine (which is to be arranged by the

Contractor), all the burrs from the pipes shall be removed. G.I. pipeswith bends shall be buried in soil / concrete in such a way that thebends shall be totally concealed. For G.I. pipes buried in soil, bitumencoating shall be applied on the buried lengths. Installation o f G.I. pipesshall be undertaken well before paving is completed and necessarycoordination with paving agency shall be the responsibility of ElectricalContractor. The open ends of pipes shall be suitably plugged with G.I.plugs after they are laid in final position. G.I. plugs shall be supplied bythe Contractor at no extra cost.


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1.5.5 Laying in Open Ducts.

a) Open ducts with suitable removable covers (RCC slabs orchequered plates) are generally provided in substations, switch rooms,plant rooms, and workshops etc.for taking the cables. The cable ducts

should be of suitable dimensions for the number of cables involved.

b) Laying of cables with different voltage ratings in the same duct shallbe Avoided. Where it is inescapable to take HV & MV cables s ametrench, they shall be laid with a barrier between them or alternatively,one of the two (HV / MV) cables may be taken through pipe(s).

Splices or joints of any type shall not be permitted inside the ducts.

a) The cables shall be laid directly in the duct such that unnecessarycrossing of cables is avoided.

b) Where specified, cables may be fixed with clamps on the walls of theduct or taken in hooks / brackets / cable trays through in ducts.

c) Where specified, ducts may be filled with dry sand aft er the cablesare laid and covered as above, or finished with cement plaster,specially in high voltage applications.

1.5.6 Laying on Surface

The method may be adopted in places like switch rooms, workshops,tunnels, rising (distribution) mains in buildings etc. This may benecessitated in the works of additions and / or alternations to theexisting installation, where other methods of laying may not be feasible.Cables may be laid in surface by any of the following methods asspecified:

a) Directly clamped by saddles or clamps

b) Supported on cradles

c) Laid on troughs / trays duly clamped.

1.5.7 Laying on Cable Tray

This method may be adopted in places like indoor substations, air -conditioning plant rooms; generator rooms etc. or where long horizo ntalruns of cables are required within the building and where it is notconvenient to carry the cable in open ducts. This method is preferredwhere heavy sized cables or a number of cables are required to be laid.The cable trays may be either of perforat ed sheetsType or ladder type as specified.


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1.5.8 Jointing

i) Location

a) Before laying a cable, proper locations for the proposed cable joints,if any, shall be decided, so that when the cable is actually laid, the

joints are made in the most suitable places. As far as possible, waterlogged locations, carriage ways, pavements, proximity to telephonecables, gas or water mains, inaccessible places, ducts, pipes, racks etc.shall be avoided for locating the cable joints.

b) Joints shall be staggered by 2 m to 3 m when joints are to be donefor two or more cables laid together in the same trench.ii) Joint pits

a) Joints pits shall be of sufficient dimensions as to allow easy andcomfortable working. The sides of the pit shall be well protected fromloose earth falling into it. It shall also be covered by a tarpaulin to

prevent dust and other foreign matter being blown on the exposedjoints and jointing materials.

b) Sufficient ventilation shall be provided during jointing operation inorder to disperse fumes given out by fluxing.

iii) Safety precaution

a) A caution board indicating CAUTION CABLE JOINTING WORKIN PROGRESS shall be displayed to warn the public and traffic wherenecessary.

b) Before jointing is commenced, all safety precautions like isolation,discharging, earthing, display of caution board on the controllingswitchgear etc. shall be taken to ensure that the cable wound not beinadvertently charged form live supply. Metallic armour and externalmetallic bonding shall be connected to earth. Where Permit to Worksystem is in vogue, safety procedures prescribed shall be compliedwith.

iv) Jointer

Jointing work shall be carried out by a licensed / experienced (where

there is no licensing system for jointers) cable jointer.

1.5.9 Testing

i) Testing before laying All cables, before laying, shall be tested with a500 V megger for cables of 1.1 KV grade, or with a 2500 / 5000 Vmegger for cables of higher voltage. The cable cores shall be tested for


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continuity, absence of cross phasing , insulation resistance fromconductors to earth / armour and between conductors.

ii) Testing before backfilling

All cables shall be subjected to the above mentioned tests, before

covering the cables by protective covers and backfilling and also beforetaking up any jointing operation.

iii) Testing after laying

a) After laying and jointing, the cable shall be subjected to a 15 minutespressure test. DC pressure testing may normally be preferredcompared to AC pressure testing.

b) In the absence of facilities for pressure testing as above, it issufficient to test for one minute with 1,000 V megger for cables of 1.1KV grade and with 2500 / 5000 V megger for cables of higher voltages.

1.5.10 Measurement

All measurement will be made as per guidelines la id under the latestedition of the General Specifications for Electrical works (Part I andII) of APWD. All the works in progress will be jointly measured by therepresentative of the Engineer -in-Charge and the Contractorsauthorised agent. Such measurements will be got recorded in themeasurement book by the Engineer -in-Charge or his authorisedrepresentative and signedin token of acceptance by the Contractor or his authorisedrepresentative.

1.6 List of Construction Equipment / Testing InstrumentThe Contractor shall have all necessary construction equipment, toolsand tackles, testing instruments to carry out the erection works and tocommission the system as specified. A list of construction equipmentwhich contractor possesses with quantity shall be indicated in the bidalong with model numbers and make. These shall include but notlimited to the following and these shall be brought to site by Contractorbefore the start of work.

A. Equipment

1. Portable grinder2. Portable welding machine3. Portable gas cutting / welding set4. Pipe threading machine5. Pipe bending machine (hydraulic)6. Portable drill machine suitable to take up drilling for differentsizes as per requirement7. Dewatering pumpsets (diesel driven)


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8. Power hacksaw9. Conduit dye set10. Hydraulic crimping machine11. Hand crimping tool12. Portable electric blowers, vacuum cleaners13. Miscellaneous items such as sling, pulleys tarpaulins,

wooden sleepers, ladders, etc. as required.14. Safety belts, safety goggles, hand gloves15. Separate tool kit for each electrician

B. Test Instruments

1. Insulation tester 0-500-1000 V hand driven2. Insulation tester 2500 / 5000 V motor driven3. Phase sequence indicator4. Earth megger5. Single phase variac6. Phase variac7. AVO meter / multimeter

8. AVO meter / multimeter9. Portable ammeter, wattmeter, P.F. meter10. Portable voltmeter11. Clip on meters of different ranges12. Tachometer13.Kelvins double bridge for measurement of very lowresistance14. DC high pot test kit15. LUX METER to measure illumination levels

1.7 SPECIFIC TECHNICAL REQUIREMENT

1.7.1 All wirings for light and power circuits shall be in PVC conduitsrecessed in wall / ceiling.

1.7.2 All 5A and 15A switches shall be piano type of approved make.17.3 All wires for point wiring and the single core wires specified for sub

main and circuit wirings shall be 1.1 KV grade PVC insulated FRLScopper multistoried wires of approved brand. The multicore cablesindicated in the drawings shall, however, be PVC insul ated andsheathed armored aluminium underground cables of approved brands.

1.7.4 Supply of light fittings, fans and exhaust fans have been included in thescope of this tender.

1.7.5 All 6A receptacles shall be flush type and shall have 5 pins with 1 pi n

for earth connection and 2 pins each for Phase and neutralconnections. 16A receptacles shall have 6 pins (suitable for connectingboth 6A and 16A plug tops) with 2 pins each for phase, neutral andearth connections.

1.7.6 Samples of all the materials to be used in the work shall be submittedto the Engineer-in-Charge (Elect.) for approval. No material other thanthose approved by the NRL shall be used in any of the works.


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In case of any materials other than those approved by the E iC (Elect.)is detected, the same shall be replaced by the Tenderer with theapproved quality, free of cost, failing which, the owner shall have rightto withhold all pending bills due to the Contractor, until the rectification /replacement work is completed.

1.7.7 All materials, equipment and accessories shall be of makes listed inAnnexure-2. Makes of any item(s) not specified under the list, butrequired in the work shall be approved by the Engineer-in-Charge priorto use in the works


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TECHICAL SPECIFICATION FOR AIR-CONDITIONING SYSTEM

1.0 SCOPE OF WORK

The Scope of the Works includes the following -

Supply, installation and commissioning of Slim, High Wall -mountedType 1.5TR/ 2 TR capacity Split Air -conditioning Plants with cordlessremote including all accessories 25 Nos. and 3nos 5,5 TR , 2nos 11TR Ductable Air conditioning Plant

2.0 TECHNICAL SPECIFICATION

The detailed specification of the 1.5TR/2 TR Capacity Split Air -conditioning plant is as follows:-

(i) Split Air-conditioning Plant

a) Star rating: Not less than 3 star.

b) Type of Mounting: Slim High Wall Type

c) Type of Compressor: Reciprocating/Rotary

d) Material for Body of Indoor Unit: ABS

e) Temperature Control: Electronic Thermostat

f) Normal cooling capacity: 17300/23100 Btu/Hr

g) Power consumption: 1800/2500 Watts (min)

h) Minimum room Temperature: 800cu/ hr (min)

i) Air flow rate = 470/620 CFM

j) Noise level (HML) = 43/42/38; 48/47/45 db

k) Fan motor Indoor (No. of Speed) = 3 Nos

l) Fan motor Outdoor (No. of speed) = 1 Nos.

The Split Air-conditioners should confirm to IS: 1391 (Part -2)-1992 With Amendment No.1 & 2, fitted with hermetically sealed aircompressor operating on refrigerant R -22 suitable for wall mounting.

The scope of installation shall include installation as per therequirement of the Engineer -in-Charge/Consultant.


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The Air conditioners shall be suitable for 230 V, 50 Hz Singlephase AC supply, capable of performing the functi ons as cooling, aircirculating and filtering. The air conditioners shall be complete withautomatic temperature control and cut -in and cut-out etc. The airconditioners may either be provided with adjustable electronic

thermostat.

The filter pads provided shall be washable.

The refrigerant used shall be Freon-22.

The display shall be LED/LCD and provided on indoor unit or onhandset or of both. They displays shall be selectable. Remote control(Cordless) shall be provided with one On/Off timer, selectin g fan speed(Three speeds) and setting up of temperature.

The detailed specification for installation shall comprise the

following work:-

i) Mounting/Fitting indoor and outdoor units at the respectivelocations

ii) Laying refrigerant piping of 4 m length and connecting boththe units after drilling hole/holes in the wall, if required.

iii) Provision of Flare nuts, Union ,capillary etc.for connecting thecopper line with the Indoor Unit and Outdoor Units.

iv) Insulating the suction pipe with expanded po lythene foamtubing.

v) Leak testing the entire system.

vi) Charging refrigerant gas in the unit.

vii) Suitable electric wiring shall be carried out between indoorand outdoor.

viii) The indoor and outdoor unit of the Air conditioners shall beconnected through flare nuts with necessary reducers and

fasteners.

Ductable Split Air Conditioner:

Supply, physical layout, installation, testing and commissioning of 3 nos. 5.5TR and 2 Nos. 11 TR ductable split air conditioner with microprocessorcontroller along with the erection of supply duct made of 22 and 24 SWG GS


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sheet. The ducts should be covered with acoustic insulation (48kg/cu.mtr) R.P.tissue paper along with thermal insulation of duct with aluminum foil faced25mm thick glass wool (32kg/cu. Mtr) and joints sealed with PVC tape and itshould be hanged by using G.I. Fastener, angle cleat, hanging rod, J hook,and MS angle of required specification. The opening of the ducts should beconnected with aluminum powder coated grill or diffuser with VCD w hichever

is applicable. For return air grill or diffuser without VCD has to connect inceiling. The indoor and outdoor unit should be connected with proper controlcable power cable and refrigerant hard copper pipe filled with refrigerant ofrequired specifications. Insulated drain pipe should be connected from IDU tonearest drain with not less than 25mm NB hard. The main ducts should beconnected with mouth piece of IDU by a canvas with zip. The ODU has toplaced in a MS structure if necessary.

Technical specifications of the Ductable machines:

IDU for 5.5 TR M/C:

Normal cooling capacity: 66000 Btu/Hr.

Nominal Air Quantity: 2200 CFM

Fan type: Direct driven DIDW forward curvecentrifugal blower.

Fan quantity: 2 nos.

Fan Discharge: Horizontal.

No. of fan motor: One.

Control Type: microprocessor LCD display.

ODU for 5.5 TR M/C:



Fan type: Centrifugal Fan

Fan quantity: 1 no.

Fan Discharge: Horizontal.No. of fan motor: One.

Compressor Type: Scroll (Copeland Make)


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IDU for 11 TR M/C:



Fan type: Direct driven DIDW forward curvecentrifugal blower.


Fan Discharge: Horizontal/Vertical.

No. of fan motor: One.

Control Type: microprocessor LED display.

ODU for 11 TR M/C:

Number ODU: Two.



Fan type: Centrifugal Fan


Fan Discharge: Horizontal/Vertical.

No. of fan motor: Two.

Compressor Type: Scroll (Copeland Make.)


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TECHICAL SPECIFICATION FOR ANALOGUE ADDRESSA BLE FIRE ALARMSYSTEM

3.1. SCOPE OF WORK

3.1.1. The scope of work shall include designing supplying and installing testing andcommissioning of Analogue Addressable Fire Detection cum Alarm Systemwith central monitoring system. This shall conform to r elevant latest standardsfor fire alarm systems.

3.1.2 It shall be possible to trip from the Fire Alarm Panel through the use ofAddressable Output Modules, individual AHU activated by the fire signal ofspecified detectors.

3.1.4 The Building shall have a multi zone panel with each area forming of one ormore software programmed zones.

3.1.5 All wiring shall be done using 2c x 1.5mm2 PVC insulated armored coppercable. (FRLS).

3.1.4 The equipment shall have UL approved system.

3.2 GLOSSARY OF TERMS

FIRE ALARM PANEL (FACP)

a) This is a microprocessor-based panel which shall be connected to the variousdetectors/devices by means of 2 wire loops.

b) The Fire alarm control panel shall be able to supervise individual detectorsfor proper performance as well as to give pinpoint location of fire alarm.

c) The panel shall have hooter alarm as well as facility for cutting off of AHUsand ventilation fans.

3.2.1. LOOP

a) A loop shall mean a 2-wire circuit connecting minimum 126 addressabledetectors/devices

b) The loop card shall have built-in circuit isolator to accommodate Class Awiring.

c) The loop cards shall be of modular construction.

3.2.2 ADDRESSABLE DEVICES

This term indicates the complete group of addressable devices such asdetectors, Manual call Stations, addressable output/input modules etc.

3.2.3 DETECTORS

a) The Detector shall be analogue addressable type.


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b) The chamber should be easily removable for the purpose of easymaintenance.

c) The address programming shall be done by a Base/detector or from the Firealarm control panel.

d) The detectors shall have a common base to allow easy interchange of varioustypes of detectors.

3.2.4 MANUAL CALL STATION

a) The Manual Call Station shall be addressable typ e with input modules todefine the device/location.

b) The Manual call station shall be breakable type with suitable protection andbase box. .

3.2.5 OUTPUT MODULE

a) Output module shall mean addressable points from the Fire alarm controlpanel with potential free contacts for tripping of AHUs, power supply etc. asrequired.

3.2.6 INPUT MODULE

a) The input modules shall be of dual/single point type.

b) The dual channel module shall be selectable for Normally Open or closed.

3.2.7 FAULT ISOLATOR

a) This unit shall be placed on the loop preferably after every 20 devices and

shall be able to isolate electrical short circuit in the wiring.

b) All the other detectors shall remain functional because of the Class A wiringof the loop.

c) The isolator shall not utilize an address and shall be built into the detectorbase wherever required.

3.2.8 SOUNDERS

a) The sounders shall be of addressable type/connected by addressable module.

b) The sounders shall derive power from separate cable with vo ltage adopter.

c) It shall be capable of being directly mounted on the wall/ceiling or along withthe detector.

d) The sounder shall have an output of at least 85 db at 1 mtr. The sounder shallbe programmed to get activated in event of an alarm from a singledetector/device or a group of detectors/ devices.

3.3 FIRE ALARM SYSTEM


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3.3.1 The Fire Alarm System shall give Audio/Visual Alarm Signals when thetemperature in case of Heat Detector or smoke density in case of SmokeDetector exceeds the pre-set limit.

3.3.2 The system shall give pinpoint location of fire with warning system.

3.3.3 The system shall have a microprocessor -based control and monitoring facility.

3.3.4 It shall be possible to program each loop with up to minimum 126 /159detectors/devices.

3.3.5 Annunciation facility shall also be inbuilt into the Fire alarm control panel, thepanel being able to initiate alarm signal for any particular zone.

3.3.6 a) The system shall be fully supervised for all fault conditions with distinctivealarm operated for fault and fire conditions.

b) Test buttons and software features shall be provided to test the electroniccircuits and detector health.

3.3.7 a) The Fire alarm control panel shall be so programmed that when aparticular detector or group of detectors gives a fire signal the Fire alarmcontrol panel should be able to trip AHU/AHUs/Ventilation fans etc

b) In case of Fire in a area handled by an AHU the Fire alarm control panelshall be able to trigger a Relay that shall shut off th e AHU through anadditional contact provided in the AHU panel by the AC contractor.

3.3. 8 The system shall be based on an open protocol to ensure flexibility.

3.4 FIRE ALARM CONTROL PANEL (FACP)

3.4.1 The Fire Alarm Control Panel shall be micro proc essor based fully AnalogueAddressable, Analogue Control Unit with centralized monitoring which shallcontrol all Analogue Addressable Detectors, Manual Call Stations andSwitching Systems (for disconnecting AHU and power supply) connected withIP card output for communication with other panel and central control station(CCS).

3.4.2 a) All addressable units shall be connected to the Fire alarm control panelthrough the Loop Cards and shall be addressed through individual numbers.

b) The Fire alarm control panel shall be able to obtain analogue value for alldetectors in the circuit through a pulsed digitalized current data.

c) The Fire alarm control panel shall be able to analyses all analogue inputsfrom all addressable units, and through its own softw are and ambient levelscreening the Fire alarm control panel shall be able to identify fire, possiblefire or fault conditions.

d) The unit supervision shall be dynamic and continuous.

3.4.3 a) The Fire alarm control panel shall also give adequate warni ng signalwhenever there is dust accumulation in detectors.


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b) It should be possible to change the level of ambient alarm calibrationcondition by the use of software program.

3.4.4 a) Short / Open circuit fault shall also be reported at the Fire alarm controlpanel.

b) In such cases, the system through the use of fault isolators shall be able toisolate that segment.

c) The missing Detectors/Devices shall also be reported at the Fire alarmcontrol panel with identification of the location.

3.4.5 a) The Fire alarm control panel shall have the facility to set each smokesensor sensitivity remotely.

b)It shall also be possible to set the sensitivity to a high level or low levelbased on night or day time.(time based sensing)

3.4.6 a) When an alarm condition is sensed at the Fire alarm control panel from a

smoke or heat detector, a delay time/alarm verification period shall be started.

b) If the sensor is still in alarm after the delay time expires, an alarm conditionis reported.

c) The delay time shall be adjustable from 0 to 990 secs.

3.4.7 The Fire alarm control panel shall have the facility to perform walk test.

3.4.8 In the walk test mode, the performance of each device is checked out byinitiating the device.

3.4.9 As each device is placed into alarm the Fire alarm control panel shall print

the condition and automatically reset the device.

3.4.10 Audible devices shall be initiated, if required at a preprogrammed time.

3.4.11 If a zone is inadvertently left in walk test mode, it shall automatically reset tonormal after the idle time is exceeded.

3.4.12 During the walk test the zones other than the programmed zones shall beunder continuous supervision (normal mode).

3.4.13 In case of any alarm initiated by detector/devices the walk test shall getterminated automatically.

3.4.14 Programming functions shall include alarm/trouble type assignment, pointdescriptor assignment, alarm message assignment, etc.

3.4.15 Programming shall be carried out from the Fire alarm control panel keyboardor utilizing the authorized laptop/desktop computer software.

3.4.16 The Fire alarm control panel shall have a Liquid Crystal Display ofAlphanumeric type.

3.4.17 The display should have high resolution, backlit 2 (lines) x 40 character.


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3.4.18 In case of testing of the system from the Fire alarm control panel the Displayshall be able to give readouts of analogue value of all detectorsbeing tested.

3.4.19 The Fire alarm control panel shall also be able to carry out continuous selfmonitoring when in normal condition.

3.4.20 The Fire alarm control panel shall have either an in -built or external printercoupled to the Fire alarm control panel, which shall log all events with time.

3.4.21 The printout shall clearly indicate the event - Fire/Pre Alarm/Fault etc. Withthe unit address and time.

3.4.22 The Fire alarm control panel shall also be able to discriminate between falsealarms and fire conditions.

3.4.23 The Fire alarm control panel shall carry out priority selection of alarm in casealarm activities in two or more remotely located units simultaneously. In such

cases, the manual call stations shall have the highest priority.

3.4.24 The Fire alarm control panel shall also be able to actuate switchesautomatically in case of Fire condition that of AHUs and power supply orother systems such as piped pressurized gas supply /Access control doors.

3.4.25 The System shall be fail safe and adequate safe guards should be ensuredthat in the event of a failure of a part of the System it shall not handicap thecomplete System.

3.4.26 The agency shall be responsible for preparation and installation of SystemSoftware into the Fire Alarm Control Panel.

3.4.27 The Software shall be user friendly.

3.4.28 The system shall be secured against Software errors.

3.4.29 The system shall have the ability to be upgraded so as to incorporate morefeatures at a later date.

3.4.30 a)The Fire alarm control panel shall have its own Battery Backup of aminimum of 40 hours in normal run and then half an hour in alarm condition.

b) The back up time calculation shall be done as per relevant standards andproduced for approval.

c) The Battery shall be 2*12V (24V) DC and of sealed lead acid rechargeablemaintenance free type, housed inside the FACP.

3.4.32 The voltage rating shall be from 14V DC to 31V DC, though the voltage maybe change.

3.4.33 a)The Fire alarm control panel shall be totally enclosed dust and vermin prooftype made of minimum 13 gauge dust inhibited sheet with even baked finish.

b) The Fire alarm control panel shall be of completely solid state design.


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3.4.34 a) The logic circuitry shall be based on high noise immunity solid statehardware employing modular construction.

b) Logic cards shall be of epoxy fibber glass construction .

3.4.35 The Fire alarm control panel shall have UL approval.

3.4.36 The system shall be designed such that it shall be possible to add at least20% of the Detectors for future expansion without extra cost on the panel.

3.4.37 a)The panel should have the facility to interface with an automatic twochannel programmable speech dialer for verbal reporting of fire.

b) Fire alarm control panel shall be able to call four telephone numbers perchannel.

c) The programmable speech dialer shall have two alarm inputs and shallprovide listen-in capabilities through the built-in microphone.

d) The dialer shall have a built-in keypad for easy operation, programmingand voice recording.

3.4.39 The fire alarm panel should be provided with IP integration card

3.5 ADDRESSABLE DETECTORSMULTISENSOR DETECTOR

3.5.1 a) All detectors shall be fitted with plug -in system type, from the maintenance

and compatibility point of views.

b) An alarm condition should not affect a detectors good functioning.

c) After resetting the alarm, the detector shall resume operations withoutreadjustment of any kind.

3.5.2. a) The detector shall have a Multisensor type integrates photoelectric smokeand fixed temperature heat sensing technology.

b) It shall be possible to use a single detector type for both above and belowfalse ceiling applications.

c) The detector shall be capable of detecting fast flaming fires and slowsmoldering fires equally well.

d) The detector shall therefore be a multi technology detector or shall be o funique design whereby a single type/model can be used in applicationswhere either ISD/OSD would be normally used.

3.5.3 a)The detector shall be able to sense incipient fire by detecting the presenceof visible and invisible products of combustion.


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b) The detector shall be suitable for low voltage (between 13 to 31V DC) twowire supply.

c) The detector shall be provided with Single/Twin LED indication.

d) The sensitivity of the detector shall not vary with change in ambienttemperature, humidity, pressure or voltage variation, air currents and shouldnot trigger the false alarm due to the above condition.

3.5.4 a) The detector shall be suitably protected against dust accumulation/ ingress.

b) The detector shall be free from maintenance and function ally tested atperiodic intervals.

c) All detectors shall be identical in construction design and characteristic tofacilitate easy replacement and interchangeable by suitable programming.

3.5.5 a) The coverage per smoke detector shall strictly follow r elevant standards.

b) It shall be possible to connect Smoke Detector with Heat Detector orManual Push Button in the same circuit.

c) The sensitivity of detector shall be set from the Fire alarm control panel tosuit the site requirement.

B. HEAT DETECTOR

3.5.6 a) Heat detector shall go into the alarm mode when the temperature reaches34degree Centigrade in normal course.

b) The operator (users) shall have the option of calling up the temperaturemeasured by the specific detector as and when required .

3. 5.7 a) It shall have in-built locking mechanism to check the removal and pilferageof the detector.

b) The quiescent current flow must not exceed 400 micro amps and alarmcondition current shall be maximum 40 mille amps.

3.5.8 a) The heat detector shall be Analogue Addressable type and be able to sendanalogue output to the Fire alarm control panel regarding its condition.

b) It shall be able to communicate with the Fire alarm control panel by thepulses emitted from the Fire alarm control panel

c) The detector should be addressed through base/detector and addressstored in a non-volatile memory within the sensor or by a decade switch.

3.5.9 a) The base of the Detector shall be electronics free and interchangeable withother smoke or heat detectors.

b) The enclosure shall meet as per the relevant protection grade.

c) The voltage rating shall be between 15V -30V DC though the voltage maybe changed depending upon the working voltages of a proprietary FACP.


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3.5.10 a) The Detector shall have UL approval.

b) It shall be possible to test the Detectors working both from the FACP aswell as locally.

3.5.11 a) It shall be possible to mount the detectors in Duct Casting Unit forsampling of Supplying Air from the AHUs.

b) Secondary response indicators shall be provided for all the Above FalseCeiling Detectors.

3.5.12 a) The detector shall have twin LEDs/Single LED for 380/180 degree viewingangle.

b) LED on the detector shall blink each time the sensor is scanned by the Firealarm control panel.

c) If the Fire alarm control panel determines that the sensor is in alarm, the Fire

alarm control panel will command the sensor LED to remain on to indicate thesame.

d) Each sensor shall be capable of being tested for alarm via command fromthe Fire alarm control panel

e) Each sensor shall respond to Fire alarm control scan with the informationabout its type for identification.

3.6 MANUAL CALL STATIONS

3.6.1 a)The Manual call station shall be breakable type with suitable protection andbase box. .

b) The device shall be red in colour and suitable for surface or flush mounting.

c) Manual stations shall be interfacable to an addressable input module. Themanual station shall have normally open fire alarm and enunciator contactsand these contacts shall close on activation. Contacts shall remain closeduntil station is manually reset.

3.6.2 a) The Manual Call Station shall be fully addressable with its ownaddressable module and operated by digitized signals from the FACP.

b) The voltage range shall be from 13V -31V.

c) It shall have protection as per relevant standard.

3.7 SOUNDER

3.7.1 The sounder shall be addressable electronic type and shall givediscontinuous/ intermittent audible alarm whenever any detector or call boxoperates.


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3.7.2 The sound output from the Hooter should not be less than 85 decibels at onemeter.

3.7.3 The sounder shall be powered from Main Fire alarm control panel throughseparate 2 wire cable.

3.8 FIRE ALARM SYSTEM TESTING

3.8.1 FACP:

a) The FACP shall be visually checked for input voltage and ampere. Allzones one by one shall be de wired to check for fault signal indication in theFACP.

b) The Power Source shall be cut off and checked for stand by Supply fromthe Batteries. After six hours the FACP Source shall be switched on to checkfor auto switch over to the Mains mode.

c) Tests shall be conducted for AC fail, charger fail, DC fail, BatteryDisconnect or Battery fail. In all such cases the relevant L E D should glowand the piezo sound shall also give sound output.

d) Low battery indication, fault indication should be made available at thepanel.

3.8.2 SMOKE DETECTOR

a) The testing shall be carried out for each loop / zone,

b) Initially one detector in a zone and subsequently 2 or more disassociateddetectors in each zone shall be tested for Alarm Priority, Alarm Queuing and

Call Logging with time lapse between detectors.

c) An identified detector shall be subject to smoke aspiration from burningpaper/cigarette puffs, rubber and other mater ials which give dense smokeheld at 0.3 M distance from the detector.

d) The FACP should indicate increased analogue output for that address andafter the programmed delay time, a fire alarm signal shall be indicated. Thisdelay shall be utilized for alarm verification.

3.8.3 HEAT DETECTOR

a) The same tests in the same sequence shall be carried out for this detector

but with the application of hot air from a hair dryer.

3.8.4 COMBINED TEST

a) The combined test shall be in combination of Photoelect ric / HeatDetectors simultaneously with time lapse between application of smoke orheat or as required by the client/consultant.


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3.8.5 ADDITIONAL TEST:

a) One detector of each type will be disconnected and subjected to slow dustbuild - up by means as desired by the Consultant/client and again connectedin the circuit.

b) Any part of the Loop shall be short cir

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