Design Criteria - Electrical 20110928

8/4/2019 Design Criteria - Electrical 20110928

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APPROVAL SCHEDULE

Name Designation Signature Date

RBP Projects

A Burn Engineering Manager

T Sertic Senior Project Manager

Project Team

G Brook Senior Project Manager

T Prinsloo Engineering Manager

G Lintvelt Electrical Engineer

M v Schalkwyk Electrical Engineer Pr

B Biggs Instrumentation Engineer

TBA Mining Engineer

K Wiehl Mechanical Engineer


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1 INTRODUCTION ...................................................................................................................... 42 DESIGN BASIS ........................................................................................................................ 43 PERMANENT ELECTRICAL POWER DISTRIBUTION ............................................................ 64 SUBSTATIONS ........................................................................................................................ 95 STANDARDISATION ............................................................................................................. 176 INSTALLATION ...................................................................................................................... 177 AIRCRAFT WARNING LIGHTS ............................................................................................. 178 APPENDIX A .......................................................................................................................... 18


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2.3 When a conflict in requirements arises between this specification and other referenceddocuments, the following order of precedence shall apply:

Project Works information sheet

Construction drawings

Special conditions of contract

General conditions of contract

This specification

2.4 The following specifications referred to as guidelines

Anglo Platinum specification AGS006 General Specification for Electrical Designof Surface and Underground Installations,

Anglo Platinum specification AGS029-03 Vendor Quality Assurance,

Anglo Platinum specification AGS057-04 Design, Construction and Maintenanceof Electrical Substations and MCC Rooms,

Anglo Platinum Safety Standards ASS004,

Anglo Platinum Electrical Engineering (AEL) technical specifications.

2.5 The following basic conditions will apply;

The selection of electrical equipment shall be governed by fit for purpose, safety,

reliability, maintainability of spares and service, compatibility with specified futureexpansion, design margins, suitability for environment, economic considerations,and past service history.

The metric system of units shall be used.

English language shall be used for all drawings, texts and communications.

2.6 The following service conditions will apply;

Table 1 shown in Appendix A, details the standard requirements for ingressprotection for equipment selected, modified or designed.

All materials and equipment shall be in accordance with the following standards, (i)IEC 60144, entitled: Degrees of protection of enclosures for low voltageswitchgear and control gear, (ii) IEC 60529, entitled:

Classification of degrees of protection provided by enclosures, degrees ofprotection provided by enclosures (IP code) and (iii) IEC 60536, entitled:Classification of electrical and electronic equipment with regard to protectionagainst shock.

Equipment shall be so designed, constructed and tested to meet with design

criteria for installation at an elevation of 1800 m above sea level, as a standard,unless otherwise stated. The maximum ambient air temperature shall be 40C,and the minimum shall be -6C.


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Equipment and materials shall be suitable for continuous rated operation under

conditions stated above. The atmosphere is to be considered humid and dusty.

2.7 Design calculations shall be made to substantiate the selection and sizing of electricalfacilities, e.g. transformers, switchgear and cables. Calculations will include:

Plant and Unit Electrical Loads

Load Flow

Fault Calculations

Power Factor

Voltage Drops

Relay Settings

Cable Sizing

Earthing

Lighting Levels

Noise emission

Energy Efficiency

3 PERMANENT ELECTRICAL POWER DISTRIBUTION

3.1 Source of power

The load build up at BRPM will progressively increase and in 2012 will approach

the firm 60MVA. The base case study for the feasibility study covers the Styldrift

230ktpm concentrator being installed at BRPM. This load increase will take BRPM

over the firm capacity limit.

3.2 Eskom power

3.2.1 An Eskom substation (Styldrift) is to be located next to the mine and shall provideinterconnection between the Ngwedi substation (MTS) and the Styldriftsubstation. The Styldrift substation will comprise of the following;

132kV outdoor isolators and busbars;

132kV/33kV, 2x20MVA, (YNd1) power transformers;

132kV/11kV, 2x20MVA, (YNd1) power transformers;

Neutral earthing compensator (NEC) 360Amp 10 Sec;

Eskom metering and protection.


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Expected Styldrift substation fault levels, including future additional

transformers can be found in table 2 of AppendixA. (this is only a

guideline)

3.3 Power Factor

3.3.1 Detailed studies shall be performed on the quality of electricity and the harmoniccontent of the system. Design of harmonic filters shall be carried out byprofessional electrical engineering specialists in the field of power quality. TheTotal Harmonic Distortion (THD) of the system should be lower than 1, 5 % withindividual harmonics lower than 1 %.

3.3.2 Energy efficiency prescriptions shall include detailed studies of the prevailingquality of electricity is performed and shall include power factor correction to atleast 0, 96 lagging.

3.3.3 The overall operating power factor at the site shall not be lesser than 0, 9 lagging,at all times. This is a minimum requirement which is prescribed by the Power

Utility. In accordance with RBP energy efficiency prescriptions a factor of 0.96lagging and never leading, is deemed a requirement.

3.3.4 Power factor correction when applied to MV and LV systems shall use bulkcorrection capacitors connected to the main distribution switchboard and MCCbus bar system. Bulk correction capacitor banks shall be arranged for automaticswitching with manual facilities for manual switching on to the bus bar system instages, in order that the optimum amount of correction can be applied undervarying system load conditions.

3.3.5 Harmonic studies shall be required to assess the harmonic distortion of the

supply system and to prevent resonance occurring by incorrect selection of

harmonic filters.

3.4 HT Electrical power distribution

3.4.1 The secondaries of the 132/33kV Eskom transformers will be connected to the33kV overhead lines via a 33kV single busbar outdoor switchyard feeding back toNorth and South Shaft respectively.

3.4.2 The secondaries of the 132/11kV Eskom transformers will be connected to theStyldrift Main Consumer Substation. A 20MVA, 33kV/11kV (YNyn0) couplingtransformer will be installed between the Styldrift outdoor switchyard and

consumer substation. This will establish a firm supply to the Styldrift Mine.

3.4.3 Each distributed load centre shall be equipped with its complement oftransformer(s) fed from local HV switchgear, which latter may take the form ofone or more ring main switches or, alternatively, conventional SF6 or vacuumcircuit breaker panels. Where the distance between a transformer (or motor,etc.)and an isolatable switch supplying it, exceeds 200m, by the shortest practicableroute, local HV switchgear shall be installed.

3.4.4 An 11kV ring feed power supply shall be installed between the main consumersubstation and the underground substations. Only one supply of 550V will bedistributed via minisubs to various load centres at underground workshops, pumpstations, conveying plant and battery bays .Four hundred (400V) will be suppliedvia lighting transformers.


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3.4.5 All mini substations shall be located strategically at load centres outsidehazardous areas. An 11kV ring feed will be provided between the main consumersubstation and the above mentioned mini substations. Two supplies of 550V and400V respectively will be distributed.

3.4.6 An 11kV ring feed power supply will be provided between the main consumersubstation and essential switchboards feeding winders and its associated

auxiliaries.

3.4.7 Lighting and similar loads shall operate at 240V AC. derived from a connectionphase to neutral connection of a 400V 3 phase 4 wire system. Primarydistribution and switching for high mast lights may be use of three phase four wirecircuits.

3.4.8 In case of Eskom having a generation capacity shortage, Styldrift power

distribution will be configured in such away to make emergency reserves

available to Eskom in the form of interruptible load of TBA MVA at 33kV and TBA

MVA at 11kV [equal to 75% of the NMD specified in the BRPM electricity

agreement.]

3.5 Emergency power

3.5.1 In case of an Eskom power failure, the generator sets shall be arranged to startup and connect to the emergency substation busbar manually. Normally two orthree generators will operated in parallel in order to increase the available powerand to provide flexibility. The emergency generators will only be used to providepower to evacuate the mine, maintain ventilation and prevent the mine fromflooding.

3.5.2 The emergency supply objective is to align with the South AfricanTelecommunications and Electrical Power Supply Authority (SATEPSA) andother guideline specific requirements:

SATEPSA category 1: Protection of human life - Ensure the supply ofemergency power in the event of a major power failure.

SATEPSA category 2: Prevention of a potential health hazard -Underground conditions to be maintained in terms of ventilation to avoidheat stress of workers and the potential accumulation of hazardous gas.

SATEPSA category 3: Protect plant and assets - Maintain the integrity of

underground infrastructure where possible, prevent flooding.

Design criteria: Evacuate all underground staff within a 12 hour timeperiod; where flooding poses a risk to human life, pumps must be able torun.

3.5.3 A CASTELL type key interlocking systems will be provided between the

generator switchgear and the Consumer Substation incomers. The keys for each

circuit shall be unique and shall in no way be interchangeable.


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4 SUBSTATIONS

4.1 General design

4.1.1 All substations shall be located strategically at load centres outside hazardousareas. Substation buildings shall generally comprise of elevated structurespermitting the use of bottom entry switchgear with cable racking and trays below.

4.1.2 Substation shall be equipped with filtered pressurising fans.

4.1.3 Heat sensitive electronic equipment shall be located in a separate room providedwith air conditioning.

4.1.4 HV switchgear, within a substation, shall be divided into zones consisting of notmore than 10 12 panels per zone.

4.1.5 Each zone shall be separated from the next by means of a two-hour rated firewallfitted with a two-hour rated fire door. All doors in firewalls shall comply with therequirements of SABS 0139 in respect of Class B fire doors.

4.1.6 Any cable and/or busbar duct passing through the firewall shall have a fireproofbarrier fitted in the plane of the firewall.

4.1.7 Lighting and small power distribution boards shall be located in each substation,buildings and at strategic locations.

4.1.8 Where possible, dry type lighting transformers shall be located in basements toprevent heating up substations.

4.1.9 The load centre HV and LV switchgear shall be installed in separate rooms

divided by an effective (two-hour rated) firewall, except that where a load centrecontains one transformer only (with no prospect of further expansion) the HV andLV switchgear maybe positioned in one room. All switchgear shall always be oil-free.

4.1.10 Multiple transformers shall be located on correctly engineered bases withintransformer bays, each bay being surrounded on three sides by a fire wall ofadequate height.

4.1.11 All transformers and minisubs shall have adequately designed oil catchment,

bund walls, and stone fill and drainage valves.

4.2 Outdoor Switchyard

4.2.1 This outdoor switchyard shall be for terminating the supply feeding North andSouth shaft respectively. The switchyard shall be fully fenced with personnel andaccess gates for heavy duty vehicle as required for the installation of equipment.

33KV single busbar outdoor yard

The switchyard will accommodate the 33/11kV 20MVA, (YYn0) couplingpower transformer.

All circuit breakers will be provided with off load isolators, The isolators willbe provided with early break contacts that shall cause the respective circuit


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breaker to be opened immediately if an attempt is made to operate (openor close) the isolator.

The electrical protection systems to be incorporated into the variousfunctional elements of the switchyard shall be in accordance with Table 3in Appendix A. Protection relay panels shall be mounted in a separatebuilding outside of the switchyard, but with direct access to the yard

Operation of the circuit breakers shall be from switches mounted on amimic panel inside the building.

4.3 Surface Substations

4.3.1 All substation MV switchgear shall have a double or single bus bar systems,which consist of removable three pole circuit breakers of the vacuum type havingan interrupting rating of 31.5 kA (minimum breaking capacity), necessary auxiliarycontrol devices, instrument transformers, relays and metering equipment.

4.3.2 All MV switchgear shall be Arc-vented" The switchgear will be fitted with a ventduct allowing the gas to be released in the air outside the building.

4.3.3 All switchboards shall be of the arc proof SF6 gas insulated type with fixedpattern circuit breaker panels equipped as follows:

Spring charging motor: 110Vac from cable VT.

Closing supply: 30Vdc from battery tripping units.

Tripping supply: 30Vdc from battery tripping units.

Incomer power meter, Schneider ION 7650 with Ethernet fibre and RS485interface. (Main Consumer Substation Only)

Feeder power meter, Schneider PowerLogic PM820 with a PM8M266expansion module on all feeders. (Main Consumer Substation Only)

Incomer protection relays, Vamp 230 with arc detection and reverse powerprotection.

Feeder protection relays, Vamp 40 with arc detection.

Integral cable earthing shall be incorporated on all outgoing circuitbreakers only. (Integral cable earthing will not be required on the generatorsubstation.)

Pyrogen fire suppression systems will be installed in all incoming circuitbreakers in accordance with the guide line specifications.

4.3.4 All cables entering and leaving the substation to be covered with fire protectivecoating as per AEL 056 - Fire Protective coating specification.

4.3.5 Earth faults will be limited to 2 X 350A NEC on the secondary side of the Eskomtransformers.


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4.3.6 When the generator is selected in Dead Bus or Maintenance mode, the earth

faults will be limited to 300A by means of a 21.2 Ohms NER on the secondary

side of the generators.

4.4 Underground Substations

4.4.1 All underground substation MV switchgear shall have a single bus bar systems,which consist of a fix pattern three pole circuit breakers of the vacuum typehaving an interrupting rating of 21kA (minimum breaking capacity), necessaryauxiliary control devices, instrument transformers, relays and meteringequipment.

4.4.2 Direct acting shunt trip;

4.4.3 Underground switchgear feeding non essential loads will be installed with undervoltage relays. This will switch the switchgear automatically in the requiredposition to start the emergency generators during power outages.

4.4.4 All switchboards shall be of the arc proof SF6 gas insulated type with fixedpattern circuit breaker panels equipped as follows:

Spring charging motor: 110Vac from cable VT

Closing supply: 30Vdc from battery tripping units

Tripping supply: 30Vdc from battery tripping units

Incomer and on goer protection relays, Vamp 40 with arc detection

Integral cable earthing shall be incorporated on all outgoing circuitbreakers only

Pyrogen fire suppression systems will be installed in all incoming circuitbreakers in accordance with the guide line specifications

4.4.5 All cables entering and leaving the substation to be covered with fire protective

coating as per AEL 056 - Fire Protective coating specification.

4.5 Rating of Medium Voltage (MV) Switchgear

4.5.1 All MV switchgear shall be internal arc tested for 1 sec.

4.5.2 Surface switchgear shall have a minimum breaking capacity (Isc) of 31.5kA for 3seconds.

4.5.3 Underground switchgear shall have a minimum breaking capacity (Isc) of 20kAfor 3 seconds.

4.5.4 All MV switchgear will comply with IEC 62271-200 and IEC 62271-100 standards.

4.5.5 All MV switchgear will be rated for 11kV nominal voltage and 12kV rated voltage.

4.5.6 All MV switchgear rated lightning impulse withstand voltage will be 95kV between

phases and to earth. Note: For Altitudes above 1000m correction factors will

apply.


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4.6 Underground Stations

4.6.1 11kV/550V Distribution transformers will be used for the Main Exhaust Vent FanMCC, Primary Conveyor MCC, and the Clearwater pump station.

4.6.2 Supplies to conveyors, drill rigs and pumps will be done via mini subs and gulleyboxes.

4.6.3 The Clear water pumps will be supplied via ABB AMC 11kV outdoor starter

panels.

4.7 LV Switchgear and Control gear assemblies (MCCs).

4.7.1 LV switchgear will be installed to distribute power from step downtransformers/minisubs. The switchgear will be located at the respective loadcentres listed below:

Underground substations.

Underground pump stations.

Surface sewage pumps and settlers.

Surface mine water storage.

Conveyors.

Surface infrastructure.

4.7.2 LV Switchgear and Control gear shall be fully type-tested to IEC 61439 and IEC

61641 and its performance rating for the complete assembly.

4.7.3 Enclosures shall be the general purpose type for indoor service, or weatherprooftype for outdoor and underground service as required. Underground MCCs shallbe constructed of galvanised or stainless steel or as specified by the ElectricalEngineer.

4.7.4 Each motor control centre shall have dual 525V - 110V AC control transformer ofadequate capacity. The minimum rating shall be 2kVA.

4.7.5 Each functional unit shall consist of a moulded case circuit-breaker and a motorstarter certified to operate as a Type II co-ordination device fully tested to SANS60947-4-1 at full operational voltage + 10% and prospective short-circuit currentat that point in the system.

4.7.6 All motor starters rated up to and including 200A shall be controlled bycontactors. Motor starters above 200A shall be controlled by air circuit breakers.

4.7.7 All motor rated up to 75kW shall be protected with a thermal overload. All motorstarters rated above including 75kW will be protected by an electronic overloaddevice.

4.7.8 All MCC supplies shall be derived from the main 550V distribution switchgear.

4.7.9 Main buses shall have a minimum capacity of 600 amperes.

4.7.10 All MCC & distribution panels shall be equip with an integral earth leakage.


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4.7.11 Automatic motor restarting following voltage dips will not be provided unlessdictated by process requirements.

4.7.12 Star Delta Starters shall not be employed on any drive. Whenever possibleintelligent motor protection relays shall be used. In such situations the followingwill apply:

Programming to be standard throughout the Mine. Unique plant controlblocks must be accommodated in the plant PLC.

Schematics must reflect two interposing relays to Simocode unit. One tomonitor the field stop for indication and one for a field start facility. Thestart facility will only be enabled at the discretion of the respective plantmanager.

4.7.13 Emergency shut down (ESD) systems and emergency stops will be hard wiredback to the switchgear/MCC.

4.7.14 Voltage for electric motors will be as follows:

RatingUtilisation Voltage

Above 0.37kW up to and including 450kW 550V 3 phase

Above 1500kW-5000kW 11kV 3 phase

Note: Motors under 0,37kW may in special cases be 380V, 3 phase; however,500/550V motors are preferred. The kW break point between utilisation voltagesmay be varied for individual cases where this will provide an economicaladvantage.

4.8 Distribution transformers (11kV/550 Volts)/Lighting Transformers (550V/400V)

4.8.1 Distribution step down transformers and minisubs will be installed to provide550V power for conveyors, workshops, sewage pumps, and settlers. Lightingtransformers will be installed to provide power to surface and undergroundlighting.

11kV/550V with NER (Surface and underground)

11KV400V Neutral directly earth (Surface)

4.9 Earthing and lighting protection

4.9.1 Earthing systems shall provide low impedance earth paths for earth faults, staticdischarge and lightning protection. The system will be designed and installed inaccordance with the SANS Codes of Practice 10199 (2004) and 10313 (2008) inconjunction with SANS 62305 -1-2-3-4:2007 and IEC 62305-1-2-3-4:2006.

4.9.2 Electrical earth mats will be provided at each substation and Eskom yard.

4.9.3 Earthing underground will be via the armouring of the underground 11kV feedercables.


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4.9.4 Earthing of lighting and small power systems shall be by means of an earth

conductor integral within cable or conduit. Power circuits shall be earthed by

separate earth wire connected to the earthing grid.

4.10 Cables

4.10.1 All cables will be in accordance with SABS using PVC low halogen with a bluestripe, all conductors will be copper.

4.10.2 All surface and underground HV 11kV cables will be to SABS 1339 Type AXLPESWA insulated.

4.10.3 Low voltage cables will be to SABS 1507 600/1000V grade having steel wiredarmouring.

4.10.4 Power cables, in general will be 4 core underground, and 3 cores on surface.

4.10.5 Control cables, in general will be 3, 4, 7 and 12 cores, but where required

multicore 19 and 37 cores will be used.

4.10.6 Earthling of lighting and small power systems shall be by means of an earth

conductor.

4.11 Lighting

4.11.1 Lighting in industrial plant hazardous and non hazardous areas shall generally beby means of high pressure mercury vapour well glass luminaries mounted on thestructures, directly beneath beams, or on platform mounted poles.

4.11.2 No incandescent or other inefficient lighting technologies will be used. Wherepossible the most efficient lamp will be used to attain the required levels ofillumination and use daylight whenever possible in lieu of artificial light.

4.11.3 Luminaries will in general be of the 2 lamp 1500 open channel type, and in someareas dust/corrosion proof luminaries will be used.

Where required, general lighting for open areas within non hazardous areaindustrial plants shall be by means of 250 or 400 watt xenon or equivalentfloodlight luminaries mounted on adjacent structures or on strategicallylocated floodlight columns.

Where required general lighting for open areas within hazardous areaindustrial plants shall be by means of 400 watt high pressure mercuryvapour floodlight luminaries mounted on adjacent structures or onstrategically located floodlight columns.

High bay type 250 or 400 watt high mercury vapour luminaries shall beused in appropriate non hazardous locations such as stores workshopsetc.

Strategically placed 25m high masts using suitable high pressure sodiumfloodlights will be installed.

4.11.4 Illumination levels will be in accordance with SABS Code of practice 114 andAGS006.


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4.11.5 Luminaries types

Type of Location

Surface substations 1500 open channel fluorescent luminaires

Underground substations 1500 open channel fluorescent luminaires

Conveyors surface 1500 open channel fluorescent luminaires

Conveyors underground 1500 open channel fluorescent luminairesHaulages Energy savings lamp 13W C/W body

Stations 1500 open channel fluorescent luminaires

Pump stations 1500 open channel fluorescent luminaires

Parking Bays 1500 open channel fluorescent luminaires

Offices 1500 open channel fluorescent luminaires

4.11.6 Emergency lighting will be provided in the surface substations, winder housesand control rooms to meet the legal and safety requirements. The source ofpower will be from dedicated UPSs located inside the substations. Noemergency lighting will be installed on headgears or underground haulages. Cap

lamps will be a requirement when working in these areas.

4.11.7 No provision for lighting has been made on the access or roadway roads.

4.11.8 Outdoor lighting circuits shall generally be controlled by photo electric cells.Manual override shall be provided to permit maintenance.

4.11.9 Indoor lighting shall be controlled locally by suitably located switches.

4.12 Cable racking

4.12.1 The preferred method of cable installation is for cables to be installed above

ground with vertical cable ladders and not in direct sunlight. Cables will besupported on cable racking fixed to pipe bridges or cable/pipe ducts wherepossible, or supported on purpose made pedestals

4.12.2 Cable racking will be prefabricated using proprietary hot dipped galvanized cableracking. Galvanizing will be in accordance with AGS030.

4.12.3 Cable racking underground will be limited to substations, conveyor head endsand other engineering infrastructure such as pump stations and the loadingfacility at the shaft. All other reticulation will be done with straining wire accordingto the guide line standard.

4.12.4 Adequate segregation shall be maintained between different services. Aseparation of 600mm shall be maintained between parallel runs of instrument andelectrical cables.

4.12.5 Cables underground will generally be strapped to 10mm diameter straining cablealong the full length of the haulages, wherever racking becomes unfeasible.

4.12.6 Cable racks and trays shall be enclosed by removable top covers allowingadequate ventilation in the following situations:

Covers are required for sun shields.

4.12.7 Cable rack plinths will be of a precast type.


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4.13 Cable route

4.13.1 Cables routed underground shall be direct in ground,

HV cables shall be laid at a depth of 1000mm to top of trenched.

LV cables shall be laid at a depth 500mm to top of trenched.

4.13.2 Cable routes crossing roads will be done by means of pre cast culverts or PVCducting.

4.13.3 Communications between Styldrift and BRPM will be accomplished by means of

a 24 fiber optic cable, installed under the 33kV overhead line system between the

two complexes.

4.14 Lighting and small power installations

4.14.1 Lighting and small power in the substation buildings control rooms, offices,

change houses, etc, will be surface/flush run conduit or cable. Conduit will begalvanised.

4.14.2 550 volt, 63 amp, three phase + earth power outlets shall be provided inworkshops, winder houses, headgears and at strategic locations in plant areassuch that all principal equipment locations can be reached by use of 50 meters ofextension cable.

4.14.3 Three phase, 4-pole, 525V, 50 Hz welding and power outlets shall comply withSANS 1239, and be installed at appropriate locations such as workshops, winderhouses, headgears for supplying power to portable welders and similar loads.Sufficient circuits and number of outlets shall be provided in order that all areas of

the building can be reached with a 30m extension cord.

4.14.4 Sufficient 240 volt, 13 amp, single phase and neutral + earth convenience outletsshall be provided in all control rooms, winder cabins, domestic areas,administrative buildings, substation rooms, workshops and workshop offices.

4.14.5 Cognisance shall be taken of Business Unit standardisation when specifyingwelding sockets and plugs.

4.14.6 All outlets located within hazardous areas shall be certified for such locations.

4.15 Styldrift underground ventilation fans

4.15.1 Power to the ventilation fans will be supplied via the Underground 11kV fan

substations which are fed from the Merensky Reef underground substation. The

power to the fans will be supplied by means of a ring feed to ensure continuous

power supply to the fans in case of cable or switchgear failure.

4.16 Conveyors

4.16.1 Surface and underground conveyors will be equipped with motor control centres,

and instrumentation detailed in the Instrumentation Design Criteria.


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4.17 Compressor

4.17.1 One 60kW compressor has been allowed for on surface, which will be supplied

from a 550V minisub. This compressor will be used for the underground refuge

bays.

4.18 Pumping

4.18.1 The underground clear water pumps will be fed from the main underground

substation.

4.18.2 The surface PLC /SCADA will monitor the dam levels and pump /motor status.

5 STANDARDISATION

5.1 For ease of maintenance and to limit the spare parts inventory, it is intended that as faras is practical, each class and category of electrical equipment and cables shall be ofthe same type and supplied by the same manufacturer wherever it is used on the mine.

5.2 When similar classes and categories of electrical equipment and cables are included inpackages, vendors shall be required to purchase the same standard equipment

6 INSTALLATION

6.1 The installation of the electrical and instrument cables and equipment will be carriedout under one or more subcontracts. Main equipment, cables and bulk materials will befree issue to the installation subcontractor but minor installation materials including

fixings, brackets, steelwork for site fabricated supports, cable trays, conduit and conduitwiring, cables smaller than 6mm2, sand for cable bedding and cover, cable tiles, trenchmarkers and all consumables will be supplied under the subcontract.

7 AIRCRAFT WARNING LIGHTS

7.1 Aircraft warning lights shall be installed on headgears, high mast lights structures asrequired by international and local regulations. After installation of the headgears, theaviation lights on the high masts will not be a requirement anymore.


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8 APPENDIX A

Table No 1: Ingress Protection derivation table

First characteristic numerical Second characteristic numerical

Protection against solid

foreign objects

Meaning for theprotection of

persons against

access to

hazardous parts

with:

Protection against harmful

ingress of waterMeaning for the

Protection

against ingress

of water

IP Tests IP Tests

0 No Protection Non-protected 0 No Protection Non-protected

1

Full penetration of

50 mm diameter sphere

not allowed. Contact

with hazardous parts not

allowed. Back of hand 1

Protected against

vertically falling drops of

water Vertically dripping

2

Full penetration of

12,5 mm diameter

sphere not allowed. The

jointed test finger shall

have adequate

clearance from

hazardous parts. Finger 2

Protected against

vertically falling drops of

water with enclosure

tilted 15o

from the

vertical

Dripping up to 15o

from the vertical

3

The access probe of

2,5 mm diameter shall

not penetrate. Tool 3

Protected against

sprays to 60o

from the

vertical Minimum spraying

4

The access probe of

1,0 mm diameter shall

not penetrate. Wire 4

Protected against watersplashed from all

directions Minimum

ingress permitted

Splashing from all

directions

5

Minimum ingress of dust

permitted (no harmful

deposit) - Dust

Protected Wire 5

Protected against low-

pressure jets of water

from all directions

Minimum ingress

permitted

Hosing jets from

all directions

6

No ingress of dust -

Dust tight Wire 6

Protected against strong

jets of water, e.g. for use

on ship decksMinimum ingress

permitted

Strong hosing jets

from all directions

7

Protected against the

effects of immersion

between 15 mm and

1 m

Temporary

immersion

8

Protected against long

periods of immersion

under pressure > 1 m

Continuous

immersion


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Table No 2: Expected Styldrift substation fault levels table

Voltage Supply Points Value

Point of Common Coupling (PCC) Styldrift Substation

Number of Points of Delivery (POD)4

Point of Delivery (POD) 33kV & 11kVIsolator

Network Capability Values @ 132kV

Maximum 1 Fault level 16.83kA

Maximum 3 Fault level 18.81kA

Maximum 1 Fault level (1 x 20MVA 33kV trfr) 360A

Maximum 3 Fault level (1 x 20MVA 33kV trfr) 3.34kA

Maximum 1 Fault level (2 x 20MVA 33kV trfrs in parallel) 720A

Maximum 3 Fault level (2 x 20MVA 33kV trfrs in parallel) 6.40kA

Maximum 1 Fault level (1 x 20MVA 11kV trfr) 360A

Maximum 3 Fault level (1 x 20MVA 11kV trfr) 10.03kA

Maximum 1 Fault level (2 x 20MVA 11kV trfrs in parallel)720A

Maximum 3 Fault level (2x 20MVA 11kV trfrs in parallel) 19.21kA


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Table No 3: Electrical protection

SWITCHBOARD

FUNCTIONAL

ELEMENT

DESCRIPTION OF ELECTRICAL

PROTECTION REQUIREMENTS

Bus bar System Bus bar differential protection

Incoming feeders

(with supply side

transformers and

11 kV neutral

earthing NEC/

NER incorporated

into its protection

zone)

Transformer Buchholz protection

Transformer differential protection

NEC/NER differential protection

NEC/NER Over-current and earth fault protection

Incoming feeder earth fault residual over-current

protection

33 kV line differential protection

Incoming feeder IDMT over-current and residual

earth fault protection

Bus feeder instantaneous over-current and residual

over-current check relays

Lock out relays

Line side inter-tripping with 33 kV feeder breaker

Outgoing Feeders High set instantaneous over-current and IDMT over-

current protection

Line differential protection

Directional residual earth fault over-current protection

Phase sequence and under-voltage protection

Line side pilot wire send and receive inter-tripping

auxiliary lock out relay

Bus Coupler High set instantaneous differential over-current

protection

High set differential residual over-current earth fault

protection

Design Criteria - Electrical 20110928

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