ts105 test standard uground cable networks

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Use of this document is subject to the disclaimer on SA Power Networks website:

www.sapowernetworks.com.au

SA Power Networks.

TECHNICAL STANDARD

TS-105

www.sapowernetworks.com.au

FOR TESTING UNDERGROUND & OVERHEADNETWORKS

Published: 3 September 2012

WARNING:Printedcopiesofthisdocu

mentAREDEEMEDUNCONTROLLED.Themostup-to-dateversionislocatedontheinternet/intranet.


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TS-105Technical Standard for Testing Underground & Overhead Networks

TS - 105 Issue: 03/09/12 Authorised: Jehad Ali Date: 03/09/12 Page 2 of 17

The use of this Technical Standard is subject to the conditions stated in SA Power Networks Disclaimer.

Refer to TS-105 Appendix A for all the standard forms that are relevant to

testing and are a pre-requisite to SA Power Networks acceptance of the

Certificate ofSA Power Networks Electrical Compliance

REVISION NOTICE:

DATE EXPLANATIONOctober 2009

Restructured the document to current standard Added new clause 6.8 Minor amendment to clause 6.3.4 & 7.1

3 September 2012

Company name change only. No other content of this Technical

Standard has been altered. Any revision markings are from the October

2009 edition.

SA Power NetworksSA Power Networks means Distribution Lessor Corporation subject to atwo hundred year lease to the partnership of companies trading as SA Power Networks or SA PowerNetworks in its own right.

SA Power Networks, ABN 13 332 330 749, a partnership of:Spark Infrastructure SA (No.1) Pty Ltd, ABN 54 091 142 380Spark Infrastructure SA (No.2) Pty Ltd, ABN 19 091 143 038Spark Infrastructure SA (No.3) Pty Ltd, ABN 50 091 142 362each incorporated in AustraliaCKI Utilities Development Limited, ABN 65 090 718 880PAI Utilities Development Limited, ABN 82 090 718 951

each incorporated in The Bahamas1 Anzac Highway, Keswick, South Australia, 5035.

SA Power Networks Disclaimer:

1. The use of the information contained in this Technical Standard is at your sole risk.2. The information in this Technical Standard is subject to change without notice.3. SA Power Networks, its agents, instrumentalities, officers and employees:

a. Make no representations, express or implied, as to the accuracy of the information containedin this Technical Standard;

b. Accept no liability for any use of the said information or reliance placed on it; andc. Make no representations, either expressed or implied, as to the suitability of the said

information for any particular purpose.4. SA Power Networks and its agencies and instrumentalities do not endorse or in any respect

warrant any third party products or services by virtue of any information, material or content

referred to or included on, or linked from or to this Technical Standard.

SA Power Networks Copyright @ 2012:

This publication is copyright. SA Power Networks reserves to itself all rights in such material. Youmust not reproduce any content of this Technical Standard by any process without first obtaining SA

Power Networks permission, except as permitted under the Copyright Act 1968.

All rights reserved.

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TS-105 Issue: 03/09/12 Authorised: Jehad Ali Date: 03/09/12 Page 3 of 17


CONTENTS

1. PURPOSE ........................................................................................................................ 5

2. SCOPE ............................................................................................................................. 5

3. REFERENCES ................................................................................................................ 6

4. DEFINITIONS ................................................................................................................ 7

5. GENERAL ....................................................................................................................... 8

6. UNDERGROUND TESTING ........................................................................................ 9

6.1 Low Voltage XLPE Distribution Cables.............................................................. 9

6.1.1 Insulation Resistance ...................................................................................... 9

6.1.2 Phasing Test ................................................................................................... 9

6.1.3 Continuity Test (Resistance of Bolted Connections) ..................................... 9

6.1.4 Earth Resistance Test ................................................................................... 10

6.2 Public Lighting Cable Circuits ........................................................................... 10

6.2.1 Insulation Resistance Testing ....................................................................... 10

6.2.2 Polarity Checking ......................................................................................... 10

6.2.3 Electrical Testing ......................................................................................... 10

6.3 11 kV and 33 kV XLPE Cables Including CBD Cables ................................... 11

6.3.1 Phasing Test ................................................................................................. 11

6.3.2 Outer Sheath Insulation Resistance (Screen Wire Test) .............................. 11

6.3.3 HV Test on XLPE Cables already in Service or Previously Energised ....... 126.3.4 HV Test on New XLPE Cable ..................................................................... 12

6.3.5 Alternative HV Test Requirement on Insulation for 11kV Cables .............. 13

6.4 Paper Insulated Cables ....................................................................................... 13

6.4.1 General ......................................................................................................... 13

6.4.2 Tests on LV Cables ...................................................................................... 13

6.4.3 Test on 11KV and 33kV Cables between Cores and Earth ......................... 14

6.5 66kV Oil Filled Cables ........................................................................................ 14

6.5.1 Core to Sheath Test after Repairs ................................................................. 14

6.5.2 Outer Sheath Integrity Test .......................................................................... 14

6.6 66kV XLPE Cables .............................................................................................. 14

6.6.1 Safety ............................................................................................................ 14

6.6.2 Core to Sheath Test after Repairs ................................................................. 14

6.6.3 Outer Sheath Integrity Test .......................................................................... 15

6.7 Cable Identification Testing ............................................................................... 15

6.8 Network Access Permits ...................................................................................... 16

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7. OVERHEAD TESTING ............................................................................................... 17

7.1 LV ABC ................................................................................................................ 17

7.2 Buried SWER Earthing Cable Circuits ............................................................. 17

7.3 11kV and 33kV Covered Conductor and 11kV IUC ........................................ 17

7.3.1 General ......................................................................................................... 17

7.3.2 Phasing Test ................................................................................................. 17

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1. PURPOSEThis Technical Standard specifies the standard testing methodology for underground

and overhead SA Power Networks distribution networks. The guidelines mentioned in

this document are applicable to any existing, new extension, repair or replacement work

carried out that will be a component of SA Power Networks. The standard testing

techniques will assist in determining the cable performance to prove that the circuit issafe to energise or commission.

It also provides guidelines in obtaining a network access permit and clarifies the

responsibilities of SA Power Networks Internal staff and external contractors in

carrying out the duties in a safe, reliable and cost effective way with the activities

associated with SA Power Networks networks.

2. SCOPEThis technical standard provides background information and the SA Power Networks

distribution specification for the Engineers, certified Inspectors, customers andelectrical installation personnel who are engaged in the activities with testing,

maintenance and inspection of SA Power Networks distribution network.

This document should be read in conjunction with other relevant network customer

information brochures i.e.NICC 404 Information on Contractor Access & Working in

the vicinity of the Electricity Network, NICC 401 Information on Network Design &

Installation by an External Contractor, TS105 Testing Standard Appendix A - Forms

and should also consider the references supplied in clause 3 of this document.

This technical standard is available via:

DaNM/DES Intranet website; andSA Power Networks Internet website:www.sapowernetworks.com.auThe use of this document is subject to the disclaimer on SA Power Networks website:

www.sapowernetworks.com.aufor further assistance and more information concerning

this technical standard please contact the relevant SA Power Networks Manager

described in clause 4 in this document.

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3. REFERENCESAS/NZS 1026:2004: Electric Cables - Impregnated paper insulated - For working

voltages up to and including 19/33 (36) kV;

AS/NZS 3008.1.1:1998: Electrical Installations - Selection of cables - Cables foralternating voltages up to and including 0.6/1 kV - Typical Australian installation

conditions;

AS/NZS 3000:2007: Electrical Installations (known as the Australian/NewZealand Wiring Rules);

ESAA Guidelines for Safe Access to Electrical and Mechanical Apparatus;SA Power Networks Network Directives Manual;SA Power Networks Substation Instruction 3.1;SA Power Networks Switching Manual;SA Power Networks Standard Terms & Conditions;Information on Application for Network Access;NICC 404 - Information on Contractor Access & Working in the vicinity of the

Electricity Network;

NICC 401 - Information on Network Design & Installation by an ExternalContractor;

Regulations under the Electricity Act 1996;Service & Installation Rules 2009;S.A. Occupational Health, Safety and Welfare Act 1986;S.A. Occupational Health, Safety and Welfare Regulations, 1995; andTS 105 - Testing Standard Appendix AForms.

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4. DEFINITIONSApplicant- Person applying for access to the SA Power Networks network.

ASO- Authorised Switching OfficerA person authorised to issue NAPs.

SA Power Networks- SA Power Networks means Distribution Lessor Corporation

subject to a two hundred year lease to the partnership of companies trading as SA Power

Networks or SA Power Networks in its own right.

SA Power Networks, ABN 13 332 330 749, a partnership of -Spark Infrastructure SA (No.1) Pty Ltd, ABN 54 091 142 380Spark Infrastructure SA (No.2) Pty Ltd, ABN 19 091 143 038

Spark Infrastructure SA (No.3) Pty Ltd, ABN 50 091 142 362each incorporated in AustraliaCKI Utilities Development Limited, ABN 65 090 718 880

PAI Utilities Development Limited, ABN 82 090 718 951each incorporated in The Bahamas

1 Anzac Highway, Keswick, South Australia, 5035.

SA Power Networks' Manager- The SA Power Networks' Manager or the authorised

Officer serving that area of the customers installation. For specific Asset Manager

Areas and their contact details please refer to SA Power Networks internet website

www.sapowernetworks.com.auand then either under Residential Services or Business

& Government tabs, browse for Service & Installation Rules and check in Section 3,

clause 3.0 & 3.1.

Must- is to be understood as mandatory.

NAO- Network Access Officer.

NAP- Network Access Permit.

NAR- Network Access Request.

Power line means -

a set of cables for the transmission or distribution of electricity and theirsupporting structures and equipment; and

associated equipment for the transmission or distribution of electricity

Responsible Off icer- means the officer appointed by the relevant SA Power Networks

Manager to be responsible for the application of this document. There may be multiple

Responsible Officers with specific responsibilities, e.g. negotiation for supply, provision

of transformers, specification of points of supply, types of supply, servicing and

metering.

Shall- is to be understood as mandatory.

Should- is to be understood as nonmandatory, i.e. advisory or recommended.

Sui table (or suitably)- means to the satisfaction of the relevant SA Power NetworksManager.

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5. GENERALThis Instruction is applicable to any new extension or repair and replacement work.

The purpose of performing cable tests is to prove that the circuit is safe to energise or

commission. Cable testing does not necessarily indicate the condition or remaining life

of a circuit.

Isolating and earthing requirements for cables connected to transformers and switching

devices are contained in the Switching Operators Handbook.

During single phase switching, Ferro resonance conditions can be avoided in loaded

cable circuits by switching at the transformer location.

The test work area shall be defined with a red tape barrier and warning signs.

High Voltage commissioning tests on new URD cables shall be performed without

connection to other equipment.

All tests shall be performed on individual sections of HV cable. Separate sections of HV

cable shall not be connected in series and tested as a whole.

All test results shall be recorded in accordance with TS-105 - Testing Standard

Appendix-A - Forms.

All low and high voltage cables must have the point of destination clearly labelled at

both ends. As an example:

Low voltage isolator: Destination is the lot number and streetname for the first service pillar.

High voltage switch: LB1 to transformere.g. LB1 to LB1 - TC xxxxxx

Refer to E-1943 Sheet 7.11 for cable naming and labelling details.

The basis for any numbering sequence for any electrical equipment is to look at the

equipment from the kerb and circuit one is on the left side of the equipment and any

identification sequence is undertaken in a clockwise direction.

For example for a three way pillar the incoming low voltage circuit as shown on the

plan on the left side is circuit one the centre circuit is two and the right side circuit is

three.

The cable destination needs to also reflect the FINAL destination.

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6. UNDERGROUND TESTING6.1 Low Voltage XLPE Distribution Cables

The low voltage cables must be tested in the following sequence:

6.1.1Insulation ResistanceCables shall be tested for insulation resistance with an insulation tester(i.e. Megger) at 1000 Volts for 1 minute.

The minimum insulation resistance to earth or between phases shall be

100 meg-ohms.

The instrument used for this measurement shall have a minimum

resolution of 10 meg-ohms on the 0 to 500 meg-ohm range.

At the conclusion of LV insulation resistance testing, the neutrals must

be connected to the earth stakes.

6.1.2Phasing TestThe correct phasing of all LV circuits shall be checked at all positions

where the LV cables are terminated into fuse bases and where any LV

cable is run from point to point.

This test shall be performed with an instrument designed for the purpose.

Mains frequency voltage of 240 Volts is not acceptable for this test.

The neutral conductor shall be connected to the earth stake for this test.

6.1.3Continuity Test (Resistance of Bolted Connections)For loop LV UD systems, a continuity test shall be carried out on each

LV circuit to ensure that all bolted connections are complete and

adequate. The test shall be carried out as follows:

At the transformer firmly bond all 4 conductors together; andUndertake a continuity test at every point where there is a service

provision or open point. In a fused service pillar the bottom row of

fuses bases must be the point at which the test is undertaken as thatis the furthest extent of the SA Power Networks network.

The difference between the readings of each phase conductor and the

neutral for each individual test shall not be greater than 10% of each

other. Any difference in reading greater than this may indicate a loose or

dirty connection and will require further investigation.

The instrument used for this measurement should have a resolution to the

second decimal point in the 0 to 5 ohm range. A typical instrument would

be the earth Megger type and taking into account the resistance values

of the test leads.

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6.1.4Earth Resistance TestMEN AreasIn any overhead or underground network the earth resistance at any point

along the length of a LV feeder is to have a maximum resistance of 10

ohms prior to connection to the existing network.

In difficult earthing locations, alternative configurations may be utilisedwith agreement from the relevant SA Power Networks Manager, as

detailed in TS-109 (currently in DRAFT format and to be issued shortly).

CMEN AreasIn any overhead or underground network the overall resistance to earth

shall be less than 1 ohm prior to connection to the existing network.

6.2 Public Lighting Cable Circuits6.2.1Insulation Resistance Testing

The insulation resistance of public lighting circuits, including columnswired on site, shall be tested in accordance with clause 6.1.1 above.

6.2.2Polarity CheckingA visual check at each end of public lighting circuits shall be carried

prior to commissioning.

6.2.3Electrical TestingThe earth and neutral are to be left disconnected at the point of supply.

The earth and neutral are to be individually meggered at 250 Volts.

The neutral and earth can be bolted up if testing is satisfactory.

Check the active by meggering the active back to the point of supply.

Check the P/L column and assembly. Apply 250 Volts to the load side of

the fuses at the column. Different types and sizes of luminaries have

different characteristics.

Any variation from the normal consistent readings for the same type ofluminarie indicates a problem in the connection or PL fitting.

Any reading that is greater then this may indicate an open circuit

problem.

Any reading that is lower then this may indicate a fault on the load side

of the fuse.

On completion the active conductor should be well clear of any metal

components in the column.

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6.3 11 kV and 33 kV XLPE Cables Including CBD CablesNew cables shall be tested individually, i.e. one phase at a time and one section

at a time.

6.3.1Phasing TestThe correct phasing of all HV circuits shall be checked at all positionswhere the HV cables have been terminated.

This test shall be performed with an instrument designed for the purpose.

240 Volt mains frequency is not acceptable for the performance of this

test. The test may be conducted on either the wire screens or the

aluminium conductors.

Where the test is performed on the wire screens, they shall be

disconnected from earth.

6.3.2Outer Sheath Insulation Resistance (Screen Wire Test)The purpose of the test is to determine soundness of the outer

polyethylene sheath against water ingress, mechanical damage and

termite attack.

Values below 0.5 meg-ohms (500 k) can indicate sheath damage.

Values between 1.0 and 10 meg-ohms may not indicate damage in a

single location. Fault finding can often be very difficult. In new cables, a

value of greater than 100 meg-ohms is required.

The integrity of the outer sheath shall be checked after cables have beenburied by an insulation tester (Megger) at 1000 Volts. The test shall be

conducted for 1 minute between each wire screen and earth after the

cable has been jointed and terminations installed.

For cables after repairs, the resistance must not be less than 10 meg-

ohms.

Where HV cable circuits are cut and joined to new circuits, sheath testing

must be carried out on the existing old circuit prior to jointing to the new

cable.

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6.3.3HV Test on XLPE Cables already in Service or Previously EnergisedExcept for new cables, testing at voltages greater than 5.0 kV is not

permitted;

DC testing above 5kV of field aged XLPE cables generallyincreases water tree growth and reduces service life; and

5kV is not considered a High Voltage DC Test.The test voltages for conducting tests on XLPE cables is now limited to

5kV after in service repairs and 10kV for new installations. A 5kV

Megger is suitable for a 5kV test on cables after repairs.

6.3.4HV Test on New XLPE CablePrior to the performance of this test, the screen wires must be connected

to the permanent earth position.

The cable shall be tested at the test voltage and the pass criteria shall be

in accordance with the following table:

Note: A new cable installation is one not previously connected and

energised to any existing network asset.

If further repair works are undertaken, and they require additional joints

to be installed, the complete HV testing procedure shall be repeated.

Application Test Voltage Criteria

After repairsSheath 1kV Megger 1 minute 10 meg-ohms min.

After repairs -Insulation

5kV Megger 1 minute

or5kV DC 1 minute

1000 meg-ohms min.

5.0 A (micro-amps)max.


New cables - Sheath 1kV Megger 1 minute 100 meg-ohms

New cables - Insulation 10kV DC 15 minute; or

10kV Megger 1 minute

1.0 A (micro-amps)

Max. 1000 meg-ohms min.

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6.3.5Alternative HV Test Requirement on Insulation for 11kV CablesWhere it is not practical to conduct a high voltage test, the test

requirements for insulation (core to screen wire) may be limited to testing

for the condition of safe to energise.

The following list of circumstances and conditions must be met as a

minimum requirement:

The work conditions shall be emergency or as determined by SAPower Networks Project Manager;

The cable circuit voltage shall be 11kV;The circuit outage duration shall be not more than 48 hours;The work shall involve extending or repairs to existing circuits;The insulation test shall be applied for 1 minute between each

phase core and screen with a 1000 Volt minimum insulation tester

(Megger); and

Typically the test result should be in the order of 1000 meg-ohms.6.4 Paper Insulated Cables

6.4.1GeneralTests on paper insulated cable systems shall be performed after new

installations, extensions or repairs.

Many CBD high voltage cable circuits are connected to older style

equipment and therefore test voltages are purposely reduced from those

in Australian Standard AS1026.

6.4.2Tests on LV CablesAn insulation resistance test shall be conducted with a 1000 Volt megger.

Test results as low as 10 meg-ohms on old cable circuits are common andtherefore considered safe to energise.

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6.4.3Test on 11KV and 33kV Cables between Cores and EarthFor three core belted cables, the test on any core shall be conducted

between the core and lead sheath with the remaining two cores connected

to earth. The test voltages and pass criteria shall be in accordance with

the table below.


11kV new cables 5kV Megger 1 minute 1000 meg-ohms

11kV after repairs 5kV Megger 1 minute 100 meg-ohms

33kV - no TFs connected 5kV Megger 1 minute 1000 meg-ohms

33kV - with TFs connected 5kV Megger 1 minute 15 meg-ohms

6.5 66kV Oil Filled Cables6.5.1Core to Sheath Test after Repairs

After repairs have been carried out on 66kV single core oil filled cables,

a DC test shall be applied between the conductor core and metallic sheath

(earthed). The test voltage shall be 60kV DC for 15 minutes.

The cable shall be considered safe to energise if the test voltage is

maintained without failure for the duration of the test. The leakage

current at the end of the test shall be recorded.

6.5.2Outer Sheath Integrity TestAn insulation resistance test between the aluminium sheath and earth

shall be conducted. Where the cable construction includes an anti-termite

metallic barrier, that barrier shall be connected to the aluminium sheath

and the insulation test performed to earth.

The test voltage applied for 1 minute shall be 5kV DC applied with either

a high voltage test set or insulation resistance tester (Megger).

6.6 66kV XLPE Cables6.6.1Safety

Careful attention to safety procedures must be carried out. Rope barriers

and warning signs are particularly important when testing 66kV cable

circuits.

6.6.2Core to Sheath Test after RepairsAfter repairs have been carried out, the 66kV XLPE cable shall be

energised at power frequency for 24 hours without load.

DC testing is not permitted.

The cable sheath link box/cross bonding system shall be put into its

normal condition.

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6.6.3Outer Sheath Integrity TestAn insulation resistance test between the metallic sheath and earth shall

be conducted. The anti-termite barrier must be connected to the metallic

sheath and the insulation test performed to earth.

The test voltage applied for 1 minute shall be 5kV DC applied with either

a high voltage test set or insulation resistance tester (Megger).

6.7 Cable Identification TestingWhenever any work is performed on cables that are installed in an SA Power

Networks transformer or switching cubicle the relevant personnel will

undertake the following in accordance with the current Network Access

Procedure:

Locate the labelling at each end of each cable and note what is recordedon the label;

If the labels match and identify each cable as being the same phase,proceed to step 2;

If the labels do not match, all cables MUST be traced and the correctidentification confirmed;

All cables are to be proved dead and earthed before continuing with thetesting;

Perform a phase identity test;Perform a screen to earth and screen to core test for high voltage cables

and a Megger test for low voltage cables in accordance with clause 6.0 of

this standard;

The test results will be written up on the relevant forms in TS-105Appendix A, F-34 (HV) / F-31 (LV) in duplicate; and

If cable test results on the existing cable/s are unsatisfactory, then thedamage to the cable/s is to be identified & repaired. The Contractors

NAP will be withheld until the damaged cable/s is rectified, then re-

issued when satisfactory cable test results are available.

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In the event that the cable identification tests are performed as a Request for

Network Access (NAR) then:

The original of the test results will be supplied to the contractor alongwith the NAP at the site handover; and

The cables to be worked on for the period of the contractors access willbe earthed. It will be the contractors responsibility to arrange for earthsto be removed and cables disconnected at both ends for the purpose of

cable testing.

The contractor MUST be present for the site handover of any SA Power

Networks assets.

6.8 Network Access PermitsTo assist in the delivery of work associated with Network Access Permits

(NAP) for contestable work it is in the contractors interests to submit the

request at the earliest opportunity. If the date is tentative only, state that.

If the date needs to be changed the Network Access Officer (NAO) has the

opportunity to log and process the request and it is in the system for scoping

and costing.

With the preliminary work completed it should improve on-site delivery of the

request at the time it is needed.

The following must be undertaken by the SA Power Networks Switching

Officer (ASO) at the time of the asset handover:

Install all the required tags and earths on isolated equipment;Clearly record all the Isolation & Earthing points on the Network Access

Permit;

Fully explain the extent of the switching and isolation that has takenplace to the Contractor receiving the access, i.e. where the nearest live /

open points are located; and

Hand over a copy of the Work Party Responsibilities and one pagesummary sheets when issuing the Network Access Permit.The Contractor accepts the Network Access Permit on the understanding that

full knowledge of the asset condition has been relayed. The Contractor should

only accept the Network Access Permit with a full understanding of the on-site

SA Power Networks network status.

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7. OVERHEAD TESTING7.1 LV ABC

New LV ABC circuits shall be tested (Meggered) for insulation resistance

between cores and earth prior to commissioning to prove safe to energise.

Confirm that all working earths have been removed.

Any cores not being tested are to be earthed including the neutral.

Ensure neutral bond is still re-connected at the completion of testing.

7.2 Buried SWER Earthing Cable CircuitsA visual check of cable connections is only required prior to the reinstatement

of trenching. Refer to E1451 and E1453 for construction details.

7.3 11kV and 33kV Covered Conductor and 11kV IUC7.3.1

GeneralA conductor covering insulation test is not required.

7.3.2Phasing TestHV covered conductors shall be tested for correct phasing in accordance

with existing procedures for bare conductor systems.

New and repaired HV ABC circuits shall be tested (Meggered) for

insulation resistance prior to commissioning to prove safe to energise and

confirm that all earths have been removed.

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