substation configuration b

MGM/lm/as-1/Sept’02

STANDARD

DOCUMENTCLASSIFICATION: CONTROLLED DISCLOSURE

REFERENCE REVTITLE: DISTRIBUTION STANDARD PART 7: SCSASABM0 3

SUBSTATIONS SECTION 2.2: DATE September 2002CONFIGURATION TYPE B, 132kV/88kV/66kV PAGE 1 OF 34TO 22kV/11kV IN THE RATING RANGE REVISION DATE:5 MVA TO 20 MVA (MV INDOOR BUSBAR) September 2005

TESCOD APPROVEDCOMPILED BY FUNCTIONAL RESP. APPROVED BY AUTHORIZED BY

Signed............................C B Clark

Signed..............................B MeyerSubstation SC

Signed.............................A Bekkerfor TESCOD

Signed.............................M N BaileyDTM for ED (D)

ContentsPage

Foreword ....................................................................................................................................... 2

Introduction.................................................................................................................................... 3

1 Scope ........................................................................................................................................ 3

2 Normative references................................................................................................................ 3

3 Definitions and abbreviations.................................................................................................... 3

4 Requirements............................................................................................................................ 4

4.1 Drawings ........................................................................................................................ 44.2 Configuration Type B substation layout design details.................................................. 54.3 Full radial (MV indoor busbar) substation packages ..................................................... 124.4 Standardized equipment ................................................................................................ 134.5 Control room .................................................................................................................. 134.6 Protection design ........................................................................................................... 154.7 A.C./D.C. supply design................................................................................................. 214.8 Telecomms and control.................................................................................................. 244.9 Metering ......................................................................................................................... 26

Annexes

A List of standardized design packages for configuration Type B ............................................... 31B Revision information ................................................................................................................. 34

CONFIGURATION TYPE B, REFERENCE REV132 kV/88 kV/66 kV TO 22 kV/11 kV IN THE SCSASABM0 3RATING RANGE 5 MVA TO 20 MVA(MV INDOOR BUSBAR)

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Foreword

The Distribution Standard is a multi-part document whose total structure is defined in Part 0. This part ofthe Distribution Standard consists of the following sections under the general title: Substations.

Distribution Standard − Part 7: Substations − Section 0: Index and guide to contents of Part 7.

SCSASABG7; Distribution Standard − Part 7: Substations − Section 1: Standardized power systemnetwork configuration as applicable to sub-transmission networks.

SCSASABK3; Distribution Standard − Part 7: Substations − Section 2: Generic substations design.

SCSASABI1; Distribution Standard − Part 7: Substations − Section 3: Distribution Group’s specificrequirements for standard practice for CAD users.

The HV/MV Substation Design Work Group comprising the following members prepared this standard:

R Maitland-Stuart Eastern Region F Wahl North Eastern RegionN Webber Southern Region J Jordaan North Eastern RegionM Bala Central Region L vd Walt Northern RegionB Meyer Western Region D Pretorius Northern RegionN Laubscher Western Region H Prinsloo North Western RegionC Clark Distribution Technology

and

J Scholtz Distribution TechnologyI Sibeko Distribution Technology

The Protection Design Work Group represented by:

A De Jongh Western RegionJ Mostert Western Region

The A.C./D.C. Design Work Group represented by:

L Drotsche Western RegionT Jacobs Distribution Technology

and the Metering Design Work Group represented by:

H Groenewald Distribution Technology

and the Telecontrol Design Work Group represented by:

B Matjila Central RegionD Gutschow Western Region

Any recommendations for corrections, additions or deletions to this standard should be sent to:

Design ManagerDistribution TechnologyPrivate Bag X1074GERMISTON1400

Telephone (011) 871-2416Fax (011) 871-2352Internet: [email protected]


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Introduction

This section of the Distribution Standard has been prepared to establish and promote standardized fullradial substation designs using standardized materials and protection philosophies, thereby generallyreducing design and construction time, equipment stock levels and costs.

1 Scope

This section of part 7 of the Distribution Standard specifies the methods, materials and equipment to beused in the design and construction of a configuration type B substation, in the voltage range132 kV/88 kV/66 kV to 22 kV/11 kV and the rating range 5 MVA to 20 MVA.

2 Normative references

The following documents contain provisions that, through reference in the text, constitute requirementsof this standard. At the time of publication, the editions indicated were valid. All standards andspecifications are subject to revision, and parties to agreements based on this standard are encouragedto investigate the possibility of applying the most recent editions of the documents listed below.Information on currently valid national and international standards and specifications can be obtainedfrom the Information Centre and Technology Standardization Department at Megawatt Park.

SCSSCAAQ2: Rev 0, Specification for feeder protection scheme (Draft)

DISASABDO: Design standard for AC & DC distribution standards.

SCSSCAAQ3: Rev 0, Phase three protection schemes for 11 kV and 22 kV reticulation cable feeders.

ESKSCAAV6: Specification on substation meter panels HV/MV indoor (Draft).

SCSASAAP9: Rev 1, Distribution Standard Part 7: Substations – Section 2.11 Configuration type K 132kV / 88 kV to 33 kV / 22 kV 40 MVA to 320 MVA.

SCSAGAAG0: Setting philosophy: Transformer protection.

ESKASAAL6 : Rev 1, Standard minimum requirements for the metering of electrical energy anddemand.

SCSSCAAS6: Distribution group’s specific requirements for busbar protection for 6.6 kV to 33 kVindoor, metal-clad switchboards.

ESKSCAAY2: Rev 0, Statistical-metering philosophy.

SCSASAAM0: Distribution Standard – Part 0: Structure, definitions, abbreviations and exemptions.

SCSASABK3: Distribution Standard − Part 7: Substations − Section 2: Generic substation design.

SCSPVAAT6: Distribution Standard − Part 9: Buyer’s guide.

SCSSCAAK3: Distribution Group’s specific requirements for 11 kV and 22 kV indoor switchgearmanufactured in accordance with NRS 003-1 and NRS 003-2.

3 Definitions and abbreviationsThe definitions and abbreviations in SCSASAAM0 shall apply.

3.1 Trf: Transforner.

3.2 Trfr: Transforner.


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3.3 B/B: Busbar.

3.4 B/BAR: Busbar.

3.5 SWER: Single Wire Earth Return.

3.6 ISOL: Isolator.

3.7 TERM SUPT: Terminal Support.

3.8 CENT: Centipede Conductor.

3.9 BRK: Circuit Breaker.

3.10 M/STL: Mild Steel.

3.11 STL: Steel.

3.12 T/BULL: Twin Bull Conductor.

3.13 FDR: Feeder.

3.14 HORN: Hornet Conductor.

3.15 CENT-BULL: Centipede conductor to Bull conductor.

4 RequirementsThe requirements of the Occupational Health and Safety Act, Act 85 of 1993 (OHS Act) and allsubsequent amendments and regulations shall be observed.

4.1 Drawings

All primary plant drawings (4000 series) and secondary plant drawings (10000 and 1100 series) arelocated on the web under substations part 7, DT projects drawings.


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4.2 Configuration Type B substation layout design details

NOTE: NO HV current transformers required.

Figure 1.1: A typical configuration Type B layout, 5 MVA and 10 MVA


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Figure 1.2: A typical configuration Type B layout, 20 MVA

4.2.1 General requirements

General requirements for a full radial (MV indoor busbar) substation are:

4.2.1.1 Clearances shall be in accordance with table 4 of SCSASABK3.


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4.2.1.2 HV equipment:

a) general HV equipment shall be in accordance with 132 kV specifications for both 132 kV and 88 kVapplications and 66 kV for 66 kV applications; and

b) voltage sensitive HV equipment shall suit the system voltage that is applicable.

4.2.1.3 MV equipment:

a) general MV equipment shall be in accordance with 22 kV specifications for both 22 kV and 11kVapplications; and

b) voltage sensitive HV equipment shall suit the system voltage that is applicable.

4.2.1.4 All sites shall allow for:

a) one HV transformer bay;

b) one MV transformer bay; and

c) a five bay indoor switchgear board comprising 1 transformer and 4 feeder panels.

The size of the substation is shown figure 2.

Figure 2: Size of substation

4.2.1.4 The main earth mat design shall allow for the maximum proposed MV feeders, i.e. “four bays”.

4.2.2 HV Transformer bay

HV transformer bays shall be in accordance with the following drawings:

a) D-DT-4313 - TRF BAY 132/11kV 20MVA CENT-BULL;b) D-DT-4364 - TRF BAY 132/11kV 10MVA CENT-BULL;c) D-DT-4337 - TRF BAY 132/11kV 5MVA CENT-BULL;d) D-DT-4375 - TRF BAY 88/11kV 20MVA CENT-BULL;e) D-DT-4376 - TRF BAY 88/11kV 10MVA CENT-BULL;f) D-DT-4377 - TRF BAY 88/11kV 5MVA CENT-BULL;g) D-DT-4318 - TRF BAY 66/11kV 20MVA CENT-BULL;


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h) D-DT-4319 - TRF BAY 66/11kV 10MVA CENT-BULL;i) D-DT-4320 - TRF BAY 66/11kV 5MVA CENT-BULL;j) D-DT-4314 - TRF BAY 132/22kV 20MVA CENT-BULL;k) D-DT-4365 - TRF BAY 132/22kV 10MVA CENT-BULL;l) D-DT-4338 - TRF BAY 132/22kV 5MVA CENT-BULL;m) D-DT-4378 - TRF BAY 88/22kV 20MVA CENT-BULL;n) D-DT-4379 - TRF BAY 88/22kV 10MVA CENT-BULL;o) D-DT-4380 - TRF BAY 88/22kV 5MVA CENT-BULL;p) D-DT-4361 - TRF BAY 66/22kV 20MVA CENT-BULL;q) D-DT-4362 - TRF BAY 66/22kV 10MVA CENT-BULL;r) D-DT-4363 - TRF BAY 66/22kV 5MVA CENT-BULL.

Figure 3.1: 5 MVA and 10 MVA transformer without post type CT’s


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Figure 3.2: 20 MVA transformer with post type CT’s

NOTE: The transformer modules allow for busbar connection only. Thus the following alterations are required:

a) 132 kV with terminal structure remove D-DT-4623 Sheet 1 - ISOL 132kV 2500A 25kA CENT and add D-DT 4622Sheet 1 - ISOL 132kV 2500A 25kA + S/A CENT & D-DT 4645 Sheet 1 - TERM SUPT 132kV 6m 20 CENT.132 kV without terminal structure remove D-DT-4623 Sheet 1 - ISOL 132kV 2500A 25kA CENT and add D-DT 4622Sheet 1 - ISOL 132kV 2500A 25kA + S/A CENT;

b) 88 kV with terminal structure remove remove D-DT-4623 Sheet 1 - ISOL 132kV 2500A 25kA CENT and add D-DT-4627 Sheet 1 - ISOL 132kV 2500A 25kA + 88 S/A CENT & D-DT 4645 Sheet 1 - TERM SUPT 132kV 6m 20 CENT.88 kV without terminal structure remove D-DT-4623 Sheet 1 - ISOL 132kV 2500A 25kA CENT and add add D-DT-4627 Sheet 1 - ISOL 132kV 2500A 25kA + 88 S/A CENT

c) 66 kV with terminal structure remove D-DT-4729 Sheet 1 - ISOL 66kV 1600A 20kA CENT and add D-DT 4728 Sheet1 - ISOL 66kV 1600A 20kA+66 S/A CENT & D-DT 4645 Sheet 1 - TERM SUPT 132kV 6m 20 CENT.66 kV without terminal structure remove D-DT-4729 Sheet 1 - ISOL 66kV 1600A 20kA CENT and add D-DT 4728Sheet 1 - ISOL 66kV 1600A 20kA+66 S/A CENT;

d) 132 kV 5 and 10 MVA remove D-DT-4631 Sheet 1 - CT 132kV 2500A 25kA CENT and add D-DT 4742 Sheet 1 - PI132kV ON CT SUPT. CENT; and

e) 66 kV 5 MVA and 10 MVA remove D-DT-4736 Sheet 1 - CT 66kV 1600A 20kA CENT and add D-DT 4743 Sheet 1 - PI66kV ON CT SUPT. CENT.

4.2.2.1 Two types of transformer bays are allowed for each system voltage:

a) a transformer bay with the surge arrester mounted onto the line isolator with a separate terminalstructure support (without HV CT’s and with HV CT’s); and

b) a transformer bay with the surge arrester mounted onto the line isolator without a separate terminalsupport (without HV CT’s and with HV CT’s).

The conductor used on all the HV transformer bay types shall be Centipede AAC.

4.2.2.2 The standard design NECRT connection allows for cable. An overhead conductor connection isavailable for use. The standard layout is common for both MV cable and conductor connectionarrangements.


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4.2.2.3 5 MVA and 10 MVA transformer

Bushing CTs shall be used, therefore HV post type CTs shall be omitted. Foundations and structures forthe future CTs shall be installed with PIs on to support the conductor.

Surge arresters shall remain positioned on the transformer and shall not be installed on the future HVCT structures.

4.2.2.4 20 MVA transformer

HV post type CTs shall be installed due to differential protection being applied.

4.2.3 MV transformer bay

MV transformer bays shall be in accordance with the following drawings:

a) D-DT-4759 Sheet 4 - CBL TRF 11kV 1C 630SQ XLPE Cu;b) D-DT-4759 Sheet 5 - CBL TRF 22kV 1C 630SQ XLPE Cu;c) D-DT-4647 - CES MV 1X630 CABLES PER PHASE BULL;d) D-DT-4649 - CES MV 2X630 CABLES PER PHASE BULL;e) D-DT-4663 - BRK PNL 11kV 1250A 25kA TRF;f) D-DT-4666 - BRK PNL 22kV 1250A 25kA TRF;g) D-DT-4664 - BRK PNL 11kV 800A 25kA FDR; andh) D-DT-4667 - BRK PNL 22kV 800A 25kA FDR.

Figure 4: 5 MVA, 10 MVA and 20 MVA Transformer with MV circuit-breakerNOTE: For 11 kV multiply D-DT-4759 Sheet 4 by 2 if 2 cables per phase are required.


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4.2.3.1 Conductor/cable sizing

The HV side of the bays shall be equipped with Centipede AAC. The conductor/cable specified for theMV side of the bays shall depend upon the size of the transformer installed (refer to table 1 and table 2).

Table 1: Transformer MV side conductor standards

1 2 3Secondary (MV) voltage

kVTransformer rating

MVAConductor type

11 5/10/20 Single covered Bull AAC22 5/10/20 Single covered Bull AAC

Table 2: Transformer MV side cable standards

1 2 3Secondary (MV) voltage

kVTransformer rating

MVAConductor type

11 5/10 1 × 630 sq. Cu cable per phase11 20 2 × 630 sq. Cu cable per phase22 5/10/20 1 × 630 sq. Cu cable per phase

4.2.4 MV busbar/feeder bay

Figure 5: Main busbar with MV feeders


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4.2.4.1 22 kV and 11 kV busbar/feeder bay

The busbar shall be the indoor design and the building shall be able to accommodate 1 × 1250 Atransformer circuit-breaker and 4 × 800 A feeder circuit-breakers. The standard relay house D-DT-5075shall be used, which allows for the MV feeder protection to be mounted on top of the circuit- breakerswith the transformer protection, metering, batteries and Telecomms/control positioned opposite theswitchboard. All panels shall be fully type tested in accordance with SCSSCAAK3.If the MV feeder cable length is greater than 100 m, then surge arresters shall be installed in theswitchgear.NOTE: These tests include special test (l): Tests to assess the effects of arcing due to an internal fault. Test set-up inaccordance with NRS 003 annex B.

4.3 Full radial (MV indoor busbar) substation packages

The hardware required for the standard configuration type B substation designs is listed in a series ofdigital (computer generated) bills of materials (BOMS). The codes and descriptions used in thisstandard are based upon the following references:

4.3.1 Substation packages

A high-level substation package allows for the following modules:

a) One HV transformer bay;

b) One MV transformer bay including indoor MV circuit-breaker;

c) One MV busbar and feeder bay for 5 MVA transformers;

d) Two MV busbar and feeder bays for 10 MVA transformers;

e) Four MV busbar and feeder bays for 20 MVA transformers;

f) One civil package;

g) One lightning/lighting package;

h) One fire protection package;

j) One protection package;

k) One A.C./D.C. package;

l) One metering package; and

m) One telecommunications/control package.

4.3.2 Module packagesThe various default module packages allow for cells as follows:

a) In a HV transformer bay module, the following cells:

1) Three terminal supports,

2) One line isolator with 3 surge arresters;

3) One circuit-breaker,

4) Three CTs/PIs,

5) One power transformer with HV/MV and neutral (if applicable) surge arresters; and

6) One NECRT,

b) In a MV transformer bay module, the following cells:


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1) One cable support,

2) The cable between the support and the circuit-breaker (default length = 20 m), and

3) One MV transformer circuit-breaker with a three-phase VT,

c) In a MV feeder bay module, the following cells:

1) Feeder circuit-breaker, and

2) Cable between feeder circuit-breaker and riser pole (default length = 40 m),

d) In the civil module: general items not linked to a specific module; (including earthing, cut, fill andwarning signs and notices);

e) For the fire protection module (oil holding dam and piping);

f) In the lightning protection/lighting module; general items not linked to a specific module;

g) For the protection module, see 4.6;

h) For the A.C./D.C. supplies module, see 4.7;

j) For the telecommunications/control module, see 4.8; and

k) For the metering module, see 4.9.

NOTE: For more detailed information on the cells in a general module package, refer to annex A.

4.3.3 Cell packagesA cell package includes the components required in the cell, which in general terms, includes:

a) Foundation details;

b) Structural/support details;

c) The equipment required in the cell, for example, surge arrester, CTs and VTs, isolator; etc.;

d) Clamps;

e) Cable, where applicable, including any necessary glands, shrouds and terminal boxes;

f) Earthing copper; and

g) All necessary fixing nuts/bolts etc.NOTE: For more detailed information on the items in a cell package, refer to annex B.

4.4 Standardized equipment

The standardized equipment, as listed in SCSPVAAT6 and SCSASABK3.

4.5 Control room

4.5.1 Control room layout

Details of the standard relay house layout (D-DT-5075) are shown in figure 6.


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Figure 6: Control room layout


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4.6 Protection design

4.6.1 Power transformer protection

The minimum protection requirements for power transformers are described in SCSAGAAG0. Theprotection schemes available for a standard configuration type B substation are specified inSCSPVAAT6, Drawing No. D-DT-9041 sheets 1 to 5.

General information is as follows:

4.6.1.1 5 MVA/10 MVA transformer applications

The transformer module for these applications is specified in drawing No. D-DT-10011 for earthed andunearthed HV neutrals.

• The HV REF protection shall be connected to the HV transformer bushing and neutral currenttransformers as no HV post type current transformers are provided. When the HV neutral is leftunearthed the REF protection shall be residually connected to the HV bushing current transformers.

• HV Instantaneous and IDMT over current protection shall be connected to the HV bushing currenttransformers.

• The MV earth fault relay shall be connected to a suitable neutral current transformer located in theNEC/RT.

• MV REF shall be connected to the MV circuit-breaker current transformers and the neutral currenttransformers located in the NEC/RT.

• When the transformer HV neutral is earthed, the IDMT HV earthfault shall be applied to the currenttransformers in the HV neutral when required by the scheme application.

4.6.1.2 20 MVA transformer applications

The transformer modules for these applications are specified in drawing No. D-DT-10006 for earthed HVneutrals and Drawing No. D-DT-10016 for unearthed neutrals.

• For this application HV post type current transformers are provided.• Differential protection and HV Instantaneous and IDMT over current protection shall be connected to

the HV post type current transformers.• Differential protection on the MV side shall be connected to the MV circuit-breaker current

transformers.• When the correct current transformers ratios are available on the HV post type CTs the HV REF

protection shall be connected to the HV post type current transformers and transformer HV neutral,otherwise use the transformer bushing CTs. When the transformer HV neutral is left unearthed theREF protection shall be residually connected to the HV post type current transformers.

• The MV earth fault relay shall be connected to a suitable neutral current transformer located in theNEC/RT.

• MV REF should be connected to the MV circuit-breaker current transformers and the neutral currenttransformers located in the NEC/RT.

• When the transformer HV neutral is earthed, the IDMT HV earthfault shall be applied to the currenttransformers in the HV neutral when required by the scheme application.

4.6.1.3 D.C. supply voltage

The applicable D.C. supply voltage at the substation shall be 110 V.


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4.6.1.4 Relay panels

The specified schemes shall be housed in 800-mm swing frame panels. The blanking plates arerequired to cover any gaps remaining in the frame as detailed in drawings D-DT 11000, D-DT-11001and D-DT-11002 whichever is applicable. Each relay panel shall be equipped with a rack mountedtransducer module as specified in ESKSCAAT7. The transducer shall provide total wattage, total vars.and white phase current and red to white phase voltage for local and remote indications. The transducermodule shall be supplied from the MV bushing current transformers and the MV busbar voltagetransformers

4.6.1.5 Cable block diagrams

Cable block diagrams for the 20 MVA and 5 MVA/10 MVA transformers are shown in figures 7a and 7brespectively when no HV busbar protection is applied.

Figure 7a: Cable block diagram for 20 MVA transformer and NO HV buszone protection


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Figure 7b: Cable block diagram for 5 MVA/10 MVA transformer and NO HV buszone protection

4.6.2 Transformer tap-change control

It is preferred that the standard configuration type B substation transformer tap-change control schemeoperates on the circulating current principle for parallel control. The scheme available for theconfiguration type B substation is specified in SCSPVAAT6, Drawing No. D-DT-9042.

4.6.2.1 The tap-change control scheme shall be supplied from the MV busbar voltage transformers.The scheme shall be mounted in the swing frame panel housing the transformer protection panel asdetailed in drawings D-DT 11000, D-DT 11001 or D-DT 11002 which ever is applicable.

4.6.2.2 The circulating current scheme requires MV current inputs, supplied from the MV transformerbushing current transformers.

4.6.2.3 The tap position indicator shall be supplied from a binary to decimal encoder

4.6.2.4 Interlocking shall be provided through input contacts from the HV and MV transformer circuit-breakers and HV and MV transformer isolators where applicable.

The cable block diagram for a transformer tap-change control scheme is shown in figure 8.


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Figure 8: Cable block diagram for transformer tap-change panel

4.6.3 HV feeder protection

No HV feeder protection shall be provided.

4.6.4 Busbar protection

MV busbar ARC protection shall be provided as standard to metal-clad indoor switchgear.

4.6.4.1 HV Busbar protection

Not applicable

4.6.4.2 MV Busbar protection

The minimum busbar protection requirements for metal clad indoor switchgear are described inSCSAGAAS6. The protection scheme available for a standard configuration type B substation isspecified in SCSPVAAT6, Drawing No. D-DT-9023 sheet 2 of 5.

The protection cell to be used is detailed in D-DT-10056.

4.6.4.2.1 Relay panels

The scheme shall be housed in an 800-mm swing frame cabinet in the position indicated in the panellayout drawing D-DT-11039. The blanking plates are required to cover the gaps remaining in the frame.


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4.6.4.2.2 Cable block diagrams

Cable block diagrams for the MV single zone overcurrent and arc detection protection schemes areshown in figure 9.

Figure 9: Cable block diagram for single zone overcurrent and arc detection

4.6.5 Under frequency load shedding

No provision shall be made for under frequency load shedding. Under frequency load shedding shall beprovided at the source substation when required.

4.6.6 MV line protection

The minimum protection requirements for rural lines and cables are described in SCSSCAAQ2 andSCSSCAAQ3 respectively. The protection schemes available for a standard configuration type Bsubstation is specified in SCSPVAAT6, Drawing No. D-DT-9002 for rural lines and D-DT-9003 sheets 1to 2 for cables.

4.6.6.1 Rural Reticulation lines up to 33kV

The applicable protection cell scheme is specified in drawing No. D-DT-10034.

4.6.6.2 Cable protection without pilot wire protection

The applicable protection cell is specified in drawing No. D-DT-10039 when no pilot wire protection isapplicable.

4.6.6.3 Cable protection with pilot wire protection

The applicable protection cell is specified in drawing No. D-DT-10035 when pilot wire protection isapplicable.


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4.6.6.4 MV Feeder protection scheme mounting

No transducer module shall be provided as an ampere transducer is already supplied in the scheme.

The schemes are to be housed in 800-mm² swing frame panel as detailed in drawings D-DT 11021, D-DT 11022 or D-DT 11023, which ever is applicable.

4.6.6.5 Communication requirements

There are no communication requirements.

4.6.6.6 Cable block diagram

A cable block diagram for the MV line protection is shown in figure 10.

Figure 10: Cable block diagram for MV line protection

4.6.7 HV and MV Busbar

Not applicable

4.6.8 HV motorised isolator control

No motorised isolator control shall be provided.

4.6.9 HV Bus Section

No HV bus section shall be provided.

4.6.10 General requirements associated with protection

4.6.10.1 The A.C./D.C. distribution cabinets are specified in 4.7.

4.6.10.2 The battery requirements are specified in 4.7.

4.6.10.3 The battery charger requirements are specified in 4.7.


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4.6.10.4 Each substation shall be equipped with a DRTU. The application is specified in 4.8.

4.6.10.5 CT and VT junction boxes shall only be installed as follows:

a) One HV CT junction box for each CT set.

4.6.10.6 The CT secondary rating shall be 1 A and the VT secondary rating shall be A.C. 110V.

4.6.10.7 The scheme supply voltage shall be D.C. 110 V.

4.6.10.8 The supervisory supply voltage shall be D.C. 48 V.

4.7 A.C./D.C. supply design

General A.C. distribution design and D.C. design criteria are specified in 4.6 of SCSASAAP9.

4.7.1 Distribution boards

Distribution boards shall be in accordance with drawing:

a) D-DT-10200 for one transformer configuration; and

b) D-DT-10212 for floor mounted A.C./D.C. distribution board with 14 x A.C. circuits and 10 D.C.circuits.

4.7.1.1 Yard A.C. distribution board

A yard A.C. distribution board (DB) consisting of the yard A.C. distribution panel, a single controlmodule, an A.C. distribution module and A.C. termination module shall be used.

The yard A.C. distribution board shall supply the yard floodlights using a 4 core 4mm2 cable. D-DT-10200 allows for cable to the first floodlight connector. It further allows for a 4 core 4mm2 cable to thefloodlight 2-way control switches at the gate and relay house.

The cable block diagram for a yard A.C. distribution board is shown in figure 11.

Figure 11: Cable block diagram for yard A.C. distribution board


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4.7.1.2 Relay house A.C./D.C. distribution board

A 19 inch, swing frame floor mounted cabinet shall be used. The board allows for the addition of extracircuits.

The A.C./D.C. board shall supply the relay house A.C. lights as well as the D.C. emergency lights.

The cable block diagram for a relay house A.C./D.C. distribution board is shown in figure 12.

Figure 12: Cable block diagram for a relay house A.C./D.C. distribution board

4.7.2 Relay house lighting circuits

The relay house lighting circuits shall be in accordance with drawing D-DT-5074 Sheet 5.

4.7.3 A.C. lights

The contractor shall do the installation and wiring of the lights, and shall supply a certificate ofcompliance for the work done. Eskom will connect both the D.C. and A.C. supplies to the respectiveswitches.

4.7.4 Emergency lights

The emergency lights shall operate in conjunction with the normal A.C. lights through a contactorcontact, operated by the A.C. light switch. A timer switch mounted on the wall may operate theemergency lights.

4.7.5 D.C. system

A single D.C. 110 V system shall be used for the supply to protection, Telecontrol and Telecommsequipment. The D.C. system has been designed for maximum capacity of equipment.


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4.7.6 BatteriesBatteries shall be in accordance with the following drawings:

a) D-DT-10231 for 48 Ah for substation up to and including 200 km; and

b) D-DT-10232 for 71 Ah for substations further than 200 km

from the responsible D.C. section.

4.7.7 Battery charger

Battery chargers shall be in accordance with drawing D-DT-10241. The battery charger shall fit into theA.C./D.C. board.

A single 110 V, 24 A battery charger, with battery cubicle shall be used.

The cable block diagram for a battery charger is shown in figure 13.

Figure 13: Cable block diagram for a battery charger

4.7.8 Supervisory requirements

4.7.8.1 Yard A.C. distribution board

Control Indication Alarm Indication1 N/A N/A A.C. supply 1 fail Optional2 N/A N/A N/A N/A3 N/A N/A N/A N/A4 N/A N/A N/A N/A

4.7.8.2 Battery charger

Control Indication Alarm Indication1 N/A N/A A.C. supply fail Charger current2 N/A N/A D.C. fail Load current3 N/A N/A Battery voltage4 N/A N/A N/A


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(Section 4.5, the RTU should be adjacent to the IDF in the diagram.)

4.8 Telecontrol Design

The Remote Terminal Unit (RTU), Intermediate Distribution Frame (IDF) and the RTU communicationinterface to be used for a Type B substation configuration are specified in buyers guide D-DT-9601, D-DT-9640 and D-DT-9651 respectively.

4.8.1 General

The telecontrol module for a substation consists of:

• Remote Terminal Unit (RTU) with its associated components. (D-DT-10601C)• Intermediate Distribution Frame (IDF). (D-DT-10640C)• Cabling

The size of the RTU and IDF as well as the amount of cables running between them is determined bythe number of I/O from the protection and DC modules.

4.8.2 I/O count

For a Type B substation the available supervisory input output points from protection schemes and DCinputs are as follows:

• 20 Analog Inputs (AI)

• 35 Digital Outputs (DO)

• 136 Digital inputs (DI)

4.8.3 RTU I/O termination

4.8.3.1 Termination via STC Krone Motherboard

The standard termination of I/O on the RTU shall be by means of a Krone STC motherboard.

Each Krone STC motherboard can provide 128 connections. For a Type B substation the first 32connections on the first STC motherboard (STC rack no. 1) will be used for the analogue inputs, whileconnections 33 - 128 is dedicated for control outputs. The Analogue input card and the Digital outputcard(s) therefore share a single Krone STC motherboard.

The Digital inputs are terminated on STC racks 2 to 3.

4.8.3.2 Termination via Burndy Connectors

The alternative method for termination is via Burndy connectors. In this case only a single 18-slot STCsubrack is required. The Burndy connectors are connected directly onto the STC cards in the sameorder as in the case of the Krone terminations.

4.8.4 RTU communications interface

For a Type B substation configuration, the communications interface used with the RTU shall be theradio interface as specified in buyers guide D-DT- 9651.


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4.8.5 Cabling

The RTU to IDF cabling for a Type B substation shall be as per D-DT-10601B sheet 1 and D-DT10601B sheet 2 for termination via STC Krone and the use of burndy connectors respectively.

The following cabling philosophy is used:

a) All telecontrol cables will be 50 pair, unarmoured.b) All cables are to be run in overhead trunking/racking.c) A single cable may not be split between different I/O cards.d) All IDF terminations and jumpering shall be in pairs i.e. there will be only one function per pair.e) Each cable shall be labelled the same on both ends and shall follow the format Tnn, where nn is the

sequence number, starting at 01 See figure 1. (Cable block)

Figure 1: Cable block diagram for RTU to IDF connection. (Each cable is a 50 pair 7m cable)

4.8.6 RTU Cabinet (Housing)

The RTU shall be housed in a 19" 48U, 800mm x 600mm swing-frame cabinet. The layout is shown indrawing D-DT 11601 sheet 1 for termination using the STC Krone motherboard and drawing D-DT11601 sheet 2 for termination using burndy connectors.

All the cables shall enter the cabinet from the top hence the requirement to leave 4U spare. The cabinetshall be filled from the top down so that all the spare space is at the bottom.

The co-axial lightning arrestors, if required, shall be mounted on the gland plate. The radio shall bemounted on a 2U modem tray directly below the power distribution rack.

4.8.6 IDF design

The IDF will consist of two 80 way verticals that can accommodate 10-way Krone modules.

Vertical A shall be used to wire the RTU side on the IDF and vertical B shall be used to wire the plantside on the IDF. The IDF layout will be determined by the type of terminations to be used.

In the case of a Krone STC motherboard being used, the IDF shall be terminated in groups of 8, i.e.pairs 9 and 10 of each 10-way Krone block shall always be spare as shown in drawing D-DT-11641sheet 1. The wiring sequence and layout on the STC Krone motherboard and IDF will therefore beidentical to allow for easy faultfinding.

If Burndy connectors are used then all 10 pairs of each Krone block shall be utilised as shown indrawing D-DT-11641 sheet 2.

RTU IDF

T01 - Analogue Inputs

T02-T03 - Control Outputs

T04-T09- Digital Inputs

Tnn - Telecomms


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4.8.6.1 Vertical A (RTU side of IDF)

The wiring sequence of the RTU side on vertical A shall be as follows:

a) Analogue Input cardsb) Digital Output cardsc) Digital Input cardsd) Communications

The communication cable shall be wired from position 80 upward to allow for an expansion in theamount of DI cards.

4.8.6.2 Vertical B (Plant side of IDF)

The wiring sequence of the Plant side on vertical B shall be as follows:

a) Transformer Protection.b) Transformer Tap-Change Protection.c) HV Feederd) LV Feedere) HV BusZonef) HV BusSectiong) LV BusZoneh) LV BusSectioni) ARC Detectionj) Under Frequency Load Sheddingk) 110 V Battery Chargerl) AC/DC Distribution Boardsm) AC Yard Distribution Boxes

The I/O of each device shall be wired in the following order:

a) Analogue signalsb) Digital output signalsc) Digital input signals

The detailed layout of the Plant vertical on the IDF is subject to the final substation design.

4.8.7 DC requirements

The DC supply voltage at the substation shall be 110V. If required, the 48V DC for the BME shall besupplied from a dedicated DC-DC converter. The 13.8V DC for the UHF radio, if required, shall besupplied from a DC-DC converter inside the RTU.

4.9 Metering

4.9.1 General

The minimum requirements for the metering of energy and demand are listed in ESKASAAL6. Statisticalmetering for this substation shall be installed in accordance with the statistical metering philosophydocument ESKSCAAY2.

The metering at this substation may consist of only statistical metering or only tariff metering or acombination of statistical and tariff metering and the different options will be discussed with the followingparagraphs.

No statistical metering shall be installed on the HV feeders. Statistical metering shall be installedupstream on the HV feeder at the supply substation.


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4.9.2 Statistical metering only

Statistical metering shall be in accordance with the following drawings:

a) D-DT-10400 for one meter point;

b) D-DT-10401 for two meter points;

c) D-DT-10402 for three meter points; and

d) D-DT-10403 for four meter points.

Statistical metering shall be installed at the MV side of the transformer and on all outgoing MV feeders.

4.9.2.1 Statistical metering scheme mounting

The metering panel shall consist of different modules that shall be installed in a standard 800mm wideswing frame that shall be housed in the relayhouse. The different modules for a typical statisticalmetering point will be the meter module (with front plate that will house the meters and testing circuitsand back plate where CT and VT incoming cables are terminated), and a voltage selection module thatwill be used to drive the ancillary circuits if needed.

NOTE 1: The Metering module can accommodate two meters.

NOTE 2: The Voltage Selection is common for six metering points.

NOTE 3: The panel can house from one to six meters.

4.9.2.2 Application for statistical metering: Transformer MV and MV feeders

The statistical metering installation shall consist of a single 800-mm wide swingframe, at least twometering modules, a voltage selection module B and at least three meters (one to meter the transformerand one each for the MV feeders).

If there are four MV feeders then another metering module shall be installed to cater for the fifthstatistical metering point. Two additional meters will also be required for the two additional feeders.

4.9.2.3 Meter requirements

The meter shall be a 63,5V 1A 3ph 4wire programmable class 0,5 unit that can record half hourlyreadings in its memory for active and reactive energy in both the forward and reverse direction. It shallcater for a RS485 port for future installation of communication media.

4.9.2.4 Voltage selection

There is only one set of VTs on the MV side and no voltage selection is necessary to drive the meters.

The voltage selection module (module B) shall to ensure continuous supply to the ancillary equipmentwith the normal supply coming from the A.C. board and if that falls away it shall chop-over to the VTsupply.

4.9.2.5 Communication

No communication medium is provided for.

4.9.2.6 Cable block

Each meter point shall have its own CT supply that shall be connected using a 4core 4mm2 cable fromthe CT Junction Box on the circuit-breakers direct to the specific meter plate at the back of the panel.The VT supply shall be connected using a 4core 4mm2 cable from the MV VT Junction Box on the


PAGE 28 OF 34

transformer circuit-breaker to the meter plate at the back of the panel and looped to the next meterplate. All the metering modules shall use the same VT supply.

A four-core cable shall be installed from the A.C. board to provide for A.C. supply to the voltageselection module.

The cable block diagram for a statistical meter point is shown in figure 15.

Figure 15: Cable block diagram for a statistical meter point

4.9.3 Tariff metering only

If the substation is built to provide supply to a single customer then tariff metering shall be installed ontothe transformer MV side and no metering shall be installed on the MV feeders.

The applicable tariff-metering scheme is detailed in the following drawings:The tariff metering shall be in accordance with drawing D-DT-10411 through to D-DT-10423.

4.9.3.1 Metering scheme mounting

The metering panel consists of different modules that shall be installed in a standard 800mm wide swingframe that shall be housed in the relayhouse. The following modules shall be installed into theswingframe: One meter module (with front plate that will house the meters and testing circuits and backplate where CT and VT incoming cables are terminated), a voltage selection module that will be used todrive the ancillary circuits and a recorder module if required.

Main and check meters shall be installed in the single meter module.


The meters shall be 63,5V 1A 3ph 4wire programmable class 0,5 units that can record half hourlyreadings in their memory for active and reactive energy in both the forward and reverse direction. Theyshall cater for a RS485 port for future installation of communication media. Energy pulse outputs will berequired for both kWh and kvarh in the forward direction.

4.9.3.3 Recorder requirements

The recorder shall be a device that can accumulate all of the energy pulse outputs from the meters,store the energy values for a minimum of 40 days, provide a communication facility for remotedownloading of energy values and provide for total kWh and kvarh output pulsing if required.


PAGE 29 OF 34


A communication medium shall be provided for the remote downloading of energy information from themetering equipment.

4.9.3.5 Cable block

Each tariff metering point shall have its own CT supply that will be connected using two 4core 4mm2

cables from the CT Junction Box on the circuit-breaker direct to the specific meter plate at the back ofthe panel. The VT supply shall be connected using a 4core 4mm2 cable from the MV VT Junction Boxon the transformer circuit-breaker to the meter plate at the back of the panel and looped to the nextmeter plate. All the metering modules shall use the same VT supply.

A 4core 4mm2 cable shall be installed from the A.C. board to provide A.C. supply to the voltage selectionmodule.

The cable block diagram for a tariff meter point is shown in figure 16.

Figure 16: Cable block diagram for a tariff meter pointNOTE 1: Two cables are required from the CT for main and check and one from the VT.

4.9.4 Tariff and statistical metering

The following paragraphs explain the different options when tariff and statistical metering are required atthe substation.

4.9.4.1 Metering scheme mounting

Statistical metering requires only one meter so two metering points can be housed in one meteringmodule. Tariff metering requires a main and a check meter and each metering point will require aseparate metering module.

4.9.4.2 Application: Tariff metering on one MV feeder

The tariff metering point shall have a full meter module and two meters. Statistical metering shall beinstalled for the transformer MV side and for the remaining MV feeders.

If there is only one remaining feeder then only one additional meter module with two meters is required.If there are two remaining MV feeders then two-meter modules will be required for statistical meteringwith three meters. For the fourth MV feeder only one additional will be needed.

A voltage selection module B shall be installed to provide auxiliary supply to the ancillary equipment.

No recorder shall be installed for this installation.


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All the equipment shall be installed in a single 800-mm swingframe.

4.9.4.3 Application: Tariff metering on two MV feeders

Each tariff metering point shall have a full meter module and two meters. Statistical metering shall beinstalled for the transformer MV side and for the remaining MV feeders.

There is only space for three-meter modules on one swingframe so statistical metering can only beprovided for the transformer and one MV feeder.

If there are two remaining MV feeders where statistical metering is required then a second swingframeshall be installed and all of the statistical metering shall be moved and installed onto the secondswingframe.


A recorder module shall be installed: one recorder shall be installed if the customer’s notified maximumdemand is smaller than 10MVA and an additional recorder shall be installed if the load is greater than10MVA.

4.9.4.4 Application: Tariff metering on three MV feeders

Each tariff metering point shall have a full meter module and two meters and one swingframe will befully occupied by the three tariff points.

A recorder module shall be installed: one recorder shall be installed if the customer’s notified maximumdemand is smaller than 10MVA and an additional recorder shall be installed if the load is greater than10MVA.


Statistical metering shall be installed on the second swingframe for the transformer MV side and for theremaining MV feeder.


The meters shall be 63,5V 1A 3ph 4wire programmable class 0,5 units that can record half hourlyreadings in their memory for active and reactive energy in both the forward and reverse direction. Theyshall cater for a RS485 port for future installation of communication media. Energy pulse outputs will berequired for both kWh and kvarh in the forward direction.

4.9.4.6 Recorder requirements

The recorder shall be a device that can accumulate all of the energy pulse outputs from the meters,store the energy values for a minimum of 40 days, provide a communication facility for remotedownloading of energy values and provide for total kWh and kvarh output pulsing if required.


A communication medium shall be provided for the remote downloading of energy information from themetering equipment.


PAGE 31 OF 34

Annex A(normative)

List of standardized design packages for configuration Type B

A.1 List of configuration Type B module packages

D-DT- Description4313 TRF BAY 132/11kV 20MVA CENT-BULL4314 TRF BAY 132/22kV 20MVA CENT-BULL4318 TRF BAY 66/11kV 20MVA CENT-BULL4319 TRF BAY 66/11kV 10MVA CENT-BULL4320 TRF BAY 66/11kV 5MVA CENT-BULL4337 TRF BAY 132/11kV 5MVA CENT-BULL4338 TRF BAY 132/22kV 5MVA CENT-BULL4361 TRF BAY 66/22kV 20MVA CENT-BULL4362 TRF BAY 66/22kV 10MVA CENT-BULL4363 TRF BAY 66/22kV 5MVA CENT-BULL4364 TRF BAY 132/11kV 10MVA CENT-BULL4365 TRF BAY 132/22kV 10MVA CENT-BULL4375 TRF BAY 88/11kV 20MVA CENT-BULL4376 TRF BAY 88/11kV 10MVA CENT-BULL4377 TRF BAY 88/11kV 5MVA CENT-BULL4378 TRF BAY 88/22kV 20MVA CENT-BULL4379 TRF BAY 88/22kV 10MVA CENT-BULL4380 TRF BAY 88/22kV 5MVA CENT-BULL

A.2 List of configuration Type B cell packages

D-DT- Description4600 TRF 132/11kV 10MVA YNd1 CENT-BULL4601 TRF 132/11kV 20MVA YNd1 CENT-BULL4602 TRF 132/22kV 10MVA YNd1 CENT-BULL4603 TRF 132/22kV 20MVA YNd1 CENT-BULL4606 TRF 88/11kV 10MVA YNd1 CENT-BULL4607 TRF 88/11kV 20MVA YNd1 CENT-BULL4608 TRF 88/22kV 10MVA YNd1 CENT-BULL4609 TRF 88/22kV 20MVA YNd1 CENT-BULL4612 NECRT 11kV 360 A 95 mm CBL4614 NECRT 22kV 360 A 95 mm CBL4618 BRK 132kV 2500A 31.5kA 3P CENT, Sheet 14622 ISOL 132kV 2500A 25kA + S/A CENT, Sheet 14627 ISOL 132kV 2500A 25kA + 88 S/A CENT, Sheet 14631 CT 132kV 2500A 25kA CENT, Sheet 14645 TERM SUPT 132kV 6m CENT, Sheet 14647 CES MV 1X630 CABLES PER PHASE BULL4649 CES MV 2X630 CABLES PER PHASE BULL4663 BRK PNL 11kV 1250A 25kA TRF4664 BRK PNL 11kV 800A 25kA FDR


PAGE 32 OF 34

Annex A(continued)

A.2 List of configuration Type B cell packages

D-DT- Description4666 BRK PNL 22kV 1250A 25kA TRF4667 BRK PNL 22kV 800A 25kA FDR4685 TRF 88/11kV 5MVA YNd1 CENT-BULL4687 TRF 88/22kV 5MVA YNd1 CENT-BULL4701 TRF 66/11kV 5MVA YNd1 CENT-BULL4702 TRF 66/11kV 10MVA YNd1 CENT-BULL4703 TRF 66/11kV 20MVA YNd1 CENT-BULL4705 TRF 66/22kV 5MVA YNd1 CENT-BULL4706 TRF 66/22kV 10MVA YNd1 CENT-BULL4707 TRF 66/22kV 20MVA YNd1 CENT-BULL4728 ISOL 66kV 1600A 20kA+66 S/A CENT, Sheet 14736 CT 66kV 1600A 20kA CENT, Sheet 14740 BRK 66kV 1600A 20kA 3P CENT, Sheet 14741 BRK 66kV 2500A 40kA 3P BULL4759 CBL TRF 11kV 1C 630SQ XLPE Cu, Sheet 44759 CBL TRF 22kV 1C 630SQ XLPE Cu, Sheet 54765 TRF 132/11kV 5MVA YNd1 CENT-BULL4766 TRF 132/22kV 5MVA YNd1 CENT-BULL

A.3 List of configuration Type B protection module packages (panel layouts)

D-DT- Description10006 PROT TRF 20MVA I/D SWG App N/S10011 PROT TRF 5/10MVA MV I/D SWG App N/S+N/L10016 PROT TRF 20MVA I/D SWG App (N/L)10034 Rural FDR for MV I/D App (1 SCH /PNL)10035 Cable FDR for MV I/D App (1 SCH/PNL)10039 Cable FDR for MV I/D App (1 Sch/PNL) No Pilot10056 1 Zone Metal Clad Bus PROT 5 Bay

A.4 List of configuration Type B protection cell packages (panel layouts)

D-DT- Description11000 PROT TRF 5/10MVA N/S+N/L11001 PROT TRF 20-80MVA MV O/D+I/D N/S11002 PROT TRF 20-80MVA MV O/D+I/D N/L11021 PROT FDR MV RURAL I/D APP (1 SCH/PNL)11022 CBL FDR MV I/D APP (1 SCH/PNL) WITH PILOT11023 CBL FDR MV I/D APP (1 SCH/PNL) NO PILOT11039 PROT BUS 1 ZONE METAL CLAD 5 BAY


PAGE 33 OF 34

Annex A(concluded)

A.5 List of configuration Type B A.C. cell and module packages (panel layouts)

D-DT- Description10200 Yard AC DIST With 1 TRFR10212 AC/DC Flr Mounted 14/10 Way10231 Battery 48A/H 110V10232 BATTERY 71A/H 110V10241 RECORDER 24 Amp

A.6 List of configuration Type B metering cell and module packages (panellayouts)

D-DT- Description10400 METERING 1 STATS POINT VOLTAGE SELECTION A10401 METERING 2 STATS POINT VOLTAGE SELECTION A10402 METERING 3 STATS POINT VOLTAGE SELECTION A10403 METERING 4 STATS POINT VOLTAGE SELECTION A10411 METERING 6 STATS POINT VOLTAGE SELECTION B10412 METERING 1 STATS POINT VOLTAGE SELECTION D


PAGE 34 OF 34

Annex B(informative)

Revision information

DATE REV. NO. COMPILER NOTESSept ‘99 0 CB Clark Original document

Feb 2000 1 I Sibeko Cell and Module drawings removed.July ‘01 1(A) CB Clark Telecomms added, Cell & Module info updated.Nov ‘01 1(B) CB Clark Telecontrol wright-up modified.Jun’02 2(A) C B Clark Telecontrol Design updated

substation configuration b

Documents

mv indoor

4core 4mm2

ct junction

cable block

kvarh output

frequency

stc krone

krone stc