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Copyright 2010
Use of this document is subject to the disclaimer on ETSA Utilities website:www.etsautilities.com.au
TECHNICAL STANDARD - TS-100
ELECTRICAL DESIGN STANDARD
FOR
UNDERGROUND DISTRIBUTION
CABLE NETWORKS
REVISION NOTICE:
DATE EXPLANATION
May 2006 Modifications to Sections; 3, 4.2, 4.3, 5.1, 5.4,
5.12, 6.1 & Table 1.
October 2006 Modifications to Sections; 4.2, 5.2, 5.4, 5.9 &
5.10.
March 2010
Restructured the document to currentstandard
Added and Updated all Sections
Section 5 upgraded by incorporating detailsfrom TS-103 - Section 7
Appendix B incorporated from TS-103
Added Appendices C, D and E
Added new Sections 5.3 and 6.5
ISSUED: MARCH 2010
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6.6 Plan of Division Changes.......................................................237. HIGH VOLTAGE NETWORK.............................................. 24
7.1 High Voltage Cables Selec tion ............................................247.1.1 Underg round HV XLPE Insula ted Cable Ratings.........................26
7.2 Design Conside ration for a Transformer and Switc hingCub ic le....................................................................................277.2.1 Padmount Transformer Spec ification/ Rating :.............................277.2.2 Switc hing Cubic le (RMU) Spec ification/ Rating : .........................287.2.3 Underground HV Switc hing Point Req uirem ents: .......................287.2.4 Transformer and/ or Switc hing Cub ic le Loc ations......................29
7.2.4.1 Transformer a nd/ or Switching Cubic le Setbac k ........317.2.5 A Loop ed High Vo ltage Network .................................................31
7.3 Other Considerations/ Requirements ...................................327.3.1 Ferroresonanc e .............................................................................327.3.2 Surge Arrestors...............................................................................327.3.3 Earthing (Ground ing ) ....................................................................327.3.4 Cable Numbering System ............................................................327.3.5 Unde rground Cabling Deta il ........................................................337.3.6 Clearanc e to Othe r Servic es........................................................337.3.7 Easement Requirement ................................................................337.3.8 Infrastruc ture Risk Assessment Req uirem ent ..............................33
8. LOW VOLTAGE NETWORK............................................... 348.1 Low Voltage Cables Selec tion .............................................34
8.1.1 Underground Low Voltage Cable Rating ....................................358.1.2 Low Voltage Paralle l Ca ble Term ina tion.....................................35
8.2 After Diversity Maximum Demand (ADMD).........................368.3 Underground Low Voltage Drop...........................................378.4 Low Vo ltage Balanc ed Loads...............................................378.5 Number of Low Vo ltage Feeders per Transformer..............378.6 Low Vo ltage Feeders Ties......................................................388.7
Service Pillar and Pit Informa tion for Residentia l Supply ....39
8.7.1 Service Pillar and Pit Selection Priorities......................................39
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8.7.2 Servic e Pillar Design Information .................................................408.7.2.1 Servic e Pilla r Setback ...................................................41
8.7.3 Footpath Servic e Pits.....................................................................418.8 Commerc ial/ Industrial Low Voltage Supply .......................428.9 Low Voltage Distribution Cabinet.........................................42
9. TRENCHING AND CONDUIT DESIGN .............................. 4310. PUBLIC LIGHTING DESIGN............................................... 4311. SUPPLY ARRANGEMENTS FOR LARGE LOADS................ 4312. PROVISION FOR FUTURE STAGES.................................... 43APPENDIX A: TABLES........................................................... 44
Shee t A1: 3 Phase Vo ltag e Drop Table o f ADMD/ No. of
Customers...............................................................................44Sheet A2: Table of ADMD for Averag e Dwelling Sizes...............45
APPENDIX B: CADDSMAN LINE DESIGN LAYERS............... 46Sheet B1: Ca ddsman Line Design Laye r Convention ................46
APPENDIX C: STANDARD DRAWING SYMBOLOGY........... 47Sheet C1: Standard Drawing Sym bols Overhead ...................47Sheet C2: Standard Drawing Sym bols Underground ..............48Sheet C3: Standard Drawing Sym bols Pub lic Lighting ............49Sheet C4: Standard Drawing Sym bols General Info ...............50
APPENDIX D: TYPICAL UG HV CIRCUIT DIAGRAM ............ 51Shee t D1: Typ ical Underground High Voltage Diag ram ............51
APPENDIX E: DRAWINGS ISSUING FLOW CHART............... 52Sheet E1: Design Draw ings Issuing Proc ess Flow Chart .............52
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1. PURPOSE
This Technical Standard is to be applied to any Design involving the installation
of underground cables that will become a component of the ETSA Utilities
distribution network It clarifies the responsibilities of Designers, Engineers, Internal
and External Contractors and Customers of ETSA Utilities in carrying out their
duties in providing a safe, reliable and cost effective ETSA Utilities underground
distribution network design.
This Technical Standard sets out the design requirements for the installation of
plant and equipment for the underground reticulation of the distribution
network. It provides specifications for:
Underground Residential (URD) and Underground Industrial Development(UID) Plan Preparation;
Single Customer and PLEC Installations; Public Lighting;
Underground High and Low Voltage Network Design Requirements; and
CAD Drawing Standard Symbology and Plan Preparation.
Furthermore, Appendices A, B, C, D and E provide tables, diagrams and flow
chart which will assist:
Low Voltage Drop based on ADMD versus Number of Customers;
Caddsman Line Design Layer Convention;
Typical Underground High Voltage Circuit Diagram; and
Drawings Issuing Flow Chart.
2. SCOPE
This Technical Standard is applicable to all specifications issued from the dateof this publication. Designs prepared prior to the publication of this standard will
be accepted to the current specification at that time.
This Technical Standard is limited to installations external to any substation
boundary. Cabling within the substation boundary needs to comply with the
ETSA Utilities Tec hnica l Sta ndard - Substa tion Design, Substa tion Co nstruction
Sta ndardand AS/NZS standards, other specifications or obligatory requirements
that shall be relevant.
This Technical Standard shall be read in conjunction with our Network
Information for Customers and Contractors brochures: NICC-401, NICC-404,NICC-052and our other Technical Standards: TS-085, TS-087, TS-101, TS-102, TS-
103, TS-104, TS-105-Append ix A (Forms), TS-107, TS-108 and shall consider the
references supplied in Section 3 of this document and also refer to any other
specifications or obligatory requirements that shall be relevant.
All Technical Standards are available via:
DaNM/DES Intranet website; andETSA Utilities Internet website: www.etsautilities.com.au
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The use of this document is subject to the disclaimer on ETSA Utilities website:
www.etsautilities.com.au for further assistance and more informationconcerning this technical standard please contact the relevant ETSA Utilities
Manager.
3. REFERENCESNOTE: Always check and refer to current relevant publications for any further
amendments before implementing any of the following mentioned references.
Electricity Act 1996 and Electricity (General) Regulations 1997;SA OHS&W Act 1986 and Regulations 1995;Energy Network Association (ENA) - ENA NENS 04 - National Guidelines For
Safe Approach Distances To Electrical and Mechanical Apparatus;
AS/NZS 1158 - Lighting for Roads and Public Spaces;AS/NZS 2067 - Substations and High Voltage Installations exceeding 1 kV
A.C.;AS/NZS 3000 - Electrical Installations - Wiring Rules;AS 4026 - Electric Cables - For Underground Residential Distribution
Systems;
AS 4799 - Installation of underground utility services and pipelines withinrailway boundaries;
AS 60038 - Standard Voltages (modified and including the full text of IEC60038);
IEEE Std 142 - Green Book - Grounding of Industrial and Commercial PowerSystems;
DTEI - Specification for Works on RoadsExcavation and Reinstatement of Road Pavement.Environment Protection Act 1993 and Environment Protection (General)
Regulations 1994;
SA Aboriginal Heritage Act 1988;SA Native Vegetation Act 1991;SA Heritage Act 1993;SA National Parks and Wildlife Act 1972;SA Natural Resources Management Act 2004; andAS/NZS ISO 14001 Environmental Management Systems.
ETSA Utilit ies Doc um ents:
ETSA Utilities Service and Installation Rules;NICC 401 - Information on Network Design and Installation by an ExternalContractor;
NICC 402 - Information on Network Public Lighting Design by an ExternalContractor;
NICC 404 - Information on Contractor Access and Working in The VicinityOf The Electricity Network;
NICC 451 - Council/Transport SA Design and Public Lighting AgreementDocument;
NICC 802 - 11kV to Low Voltage Padmount Transformers (Information andRequirements for Customers);
NICC 803 - Information Bulletin - ETSA Service Pits and Pillars;NICC 804 - Customers Guide to Supply Arrangements for Large CustomerLoads;
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TS 085 - Trenching and Conduit Standard;TS 087 - Construction Standard for Underground Cable Networks;TS 101 - Public Lighting Design Standard;TS 102 - An Easement Standard for Distribution Networks;TS 103 - General Standard for Contestable Works Gaining Connection To
The Electricity Networks;TS 105 - Testing Standard Appendix A - Forms;TS 107 - Overhead Line Design Standard;TS 108 - Technical Standard for Distribution Transformer Rooms; andETSA Utilities Relevant E-drawing Manuals.
4. DEFINITIONS
In the interpretation of this Technical Standard unless the context shall otherwise
require or admit, the Words defined in the Works Agreement and NICC 0052 -
Terms and Cond itions for Netw ork Insta llations (Ad d itiona l Contrac to r
Annexure) - N52have the same meaning.
Accredited Designer - means a designer who has satisfied ETSA Utilities Terms
and Conditions to undertake an electrical design.
Applicant-Person applying for access to the ETSA Utilities network.
AS/ NZS 3000 Wiring Rules - means the current version of the Wiring Rules
published by Standards Australia.
Bush Fire Risk Area - The ETSA Utilities Bush Fire Risk Area is any area in South
Australia so defined in the latest revision of the Regulations under the ETSA ActAmendment Act - 1988.
Backbone Feeder - is defined as the HV conductors bearing the significant
proportion of feeder load, generally including Tee offs, where four or five
overhead transformers or 2 padmount transformers and a major customer exist.
Cable - means an insulated conductor, or two or more such conductors, laid
together, whether with or without fillings, reinforcements or protective
coverings. (Note: Cable for the purpose of this manual also means aerial
bundled cables).
Conductor -means a wire, cableor form of metal designed for carrying electric
current.
CCADDDS - means Central CAD Drawing Deposit System used for sending
CAD drawings electronically between ETSA Utilities depots and Facilities
Records.
Contractor - includes but is not limited to licensed subcontractors, consultants
and sub consultants and engaged by the Applicant.
Council - means the local government authority for the site of theDevelopment.
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Connection Point - has the meaning given to that term in the Electricity
(General) Regulations 1997, namely a connection point to a transmission or
distribution network. For the purpose of this document connection point also
has the same meaning as Point of Supply as defined in AS/NZS 3000.
CST - Common Service Trench.
Development - means the development proposed by the Applicant on the
Land and any land external to that land but included in the Applicant's
proposal.
Distributor - means a person who holds a Distribution Licence, or who is
exempted from holding a licence of the Electricity Industry Act.
A Distributor is also known as the Distribution Network Service Provider(DNSP).
For the purpose of this document ETSA Utilities is the Distributor.
DTEI -means the Department for Transport, Energy and Infrastructure.
Earthed - means connected to the general mass of earth by a conductor to
ensure and maintain the effective dissipation of electrical energy.
MEN -meansMultiple Earthed Neutral Systems.
CMEN -meansCommon Multiple Earthed Neutral Systems.
ETSA Utilities - ETSA Utilities means Distribution Lessor Corporation subject to a
two hundred year lease to the partnership of companies trading as ETSA Utilitiesor ETSA Utilities in its own right.
ETSA Utilities, ABN 13 332 330 749, a partnership of -CKI Utilities Development Limited, ABN 65 090 718 880;
HEI Utilities Development Limited, ABN 82 090 718 951;
Each incorporated in The Bahamas.
Spark Infrastructure SA (No.1) Pty Ltd, ABN 54 091 142 380;
Spark Infrastructure SA (No.2) Pty Ltd, ABN 19 091 143 038;
Spark Infrastructure SA (No.3) Pty Ltd, ABN 50 091 142 362;
Each incorporated in Australia.
1 Anzac Highway, Keswick, South Australia, 5035.
ETSA Utilitie s' Manager - The ETSA Utilities' Manager or the authorised Officer
serving that area of the customers installation. For specific Asset Manager
Areas and their contact details please refer to ETSA Utilities internet website
www.etsautilities.com.au Contractors and Designers browse for Serviceand Installation Rules (S&IR) and check in Section 3.0 - Asset Manager Areas
and Contac t Details.
Elec tric al Connec tion Works - inc ludes:
Those works required for the connection of the proposed extension to ETSAUtilities distribution network; and
Any works (electrical or non-electrical) that involve work on, around, underor above the existing network.
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Elec trical Works - inc ludes:
All cable laying, cable jointing and street lighting required to service theApplicant, and any works required to connect the Applicant to the ETSA
Utilities distribution network but does not include low voltage electricity
reticulation beyond the point of supply;
Padmount transformer and switching cubicle installation; and Includes trenching, excavation, backfilling, conduits, pits, footings andrestoration.
Easement Standard -means the Easement Standard for Distribution Networks TS
102, issued by ETSA Utilities as varied from time to time.
High Voltage or High Voltage - means a nominal voltage exceeding 1,000
volts alternating current or exceeding 1,500 volts direct current.
Licensed Contractor - means an individual who is registered as a Restricted
Electrical Worker in accordance with The Plumbers, Gas Fitters and ElectriciansAct 1995, for the relevant endorsements of "Limited to works on overhead lines"
or "Limited to cable jointing and underground distribution systems up to
consumers terminals excluding (or including) lead".
Low Voltage or Low Voltage - means a nominal voltage exceeding 50 volts
alternating current or 120 volts direct current, but not exceeding 1000 volts
alternating current or 1500 volts direct current.
Must - is to be understood as mandatory.
Mains Side - The side of the street on which low voltage distributor cables areinstalled.
Network Project Officer (NPO) -The person normally responsible for managing
the applicants connection.
Overcurrent Protec tion -Protection which operates when the current exceeds a
predetermined value.
Overvoltage Protec tion -Protection that operates at a predetermined voltage
level which is greater than normal.
Padmount Transformer -is typically 11kV to Low Voltage transformer enclosed in
a metal cabinet and mounted at ground level on a concrete pad for a neat
and compact ground level installation. They shall be capable of supplying a
customer with 3 phase 230/400V at up to 2500A, in sizes ranging from 300kVA up
to and including 2000kVA. This style of transformer is the most suitable
installation in an underground area supplied by cables, within a building
structure or where a transformer has to be sited on the applicants land.
Point o f Supply -Refer to Connection Point.
Primary Plant -means Electrical apparatus on the ETSA Utilities Network which isdesigned to carry electrical energy.
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Plan of Division - means the Applicant's Plan of the proposed division of the
land into residential allotments, public roads, reserves and the like as varied
from time to time.
Projec t Mana ge r (PM) -Also referred to as Network Project Officer (NPO).
Protection - An apparatus or combination of protective equipments designed
to initiate, under predetermined abnormal conditions, the disconnection of an
element of a power system.
Servic e Side -means the non-distributor side of the street.
Service Mains - The electricity cable connecting the Customer's first point of
supply to ETSA Utilities connection point.
Shall- is to be understood as mandatory.
Should- is to be understood as nonmandatory, i.e. advisory or recommended.
Suitable (or suitably) - means to the satisfaction of the relevant ETSA Utilities
Manager.
Substation - The part of a power system, concentrated in a given place
including mainly the terminations of transmission or distribution lines switchgear
and housing which also include transformers. It generally includes facilities
necessary for system security and control. (E.g. the protective devices).
Terms and Conditions -means ETSA Utilities publication Terms and Conditionsfor External Contractor Construction, as amended from time to time.
URD - means underground residential distribution for the supply of electricity.
UID - means underground industrial distribution for the supply of electricity.
Wate rcourse - means any of the following whether permanent, overflow or wet
weather catchment only and as defined in Environment Protection (Water
Quality) Policy 2003:
a river, creek or other natural watercourse (whether modified or not);a dam or reservoir that collects water flowing in a watercourse;a lake, wetland or other body of water through which water flows;the Coorong;an artificial channel;a public stormwater disposal system; andpart of a watercourse.
Works -means the term Works as defined in the Works Agreement.
Works Agreement - means the Agreement for the Design, Construction and
Testing of Electrical Services entered into by ETSA Utilities and the Applicant forthe Development of the Land.
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5. SPECIFICATION AND DESIGN INFORMATION
ETSA Utilities will supply the specification information relating to the project
which will enable an ETSA Utilities recognised design contractor to undertake
the design on behalf of the Applicant. The information will be in accordance
with the TS-103- Gene ra l Sta ndard for Contesta b le Work Ga ining Co nnec tion to
the Electricity Network.
The designer shall prepare an electrical design layout in a form acceptable to
ETSA Utilities that is in accordance with Technical Standards, E-drawings and
other relevant specifications. If the construction is to be contestable the work to
be undertaken by both the contractor and ETSA Utilities shall be clearly defined
on the design drawing. The design needs to reflect the requirement that any
equipment that is to be installed must be to the ETSA Utilities specification.
The design drawing shall also specify that the contractor undertakes maximum
work with the parameters being, unless otherwise specified by ETSA Utilities, thatany work on an existing asset will be undertaken by ETSA Utilities. Refer to TS-
087; Section 9.0 for information on Ac c ess Permits and Connec tion to ETSA
Utilities Existing Equipment and TS-105; Section 6.8 for Network Ac c ess Permits.
The electrical design layout is to be submitted by email unless otherwise
specified by ETSA Utilities. If an email submission is not possible then the design
should be submitted on a data disk. Design data enclosed with the application
must be clearly labelled with the following information:
Applicant's Name and Application Date;
Development Name, Development Number and ETSA Utilities NotificationNumber;
Disk Number and Total Number of Related Disks (e.g. Disk 1 of 1);CAD File Name (e.g. PROJECT2.DWG);Drawing Scale (drawing must have written Scale, Scale Bar and Sheet
Size); and
Drawing Status (e.g. Preliminary, For Construction or As Constructed).
5.1 Basic Spec ification Informa tion
The information will include but not be limited to:
ETSA Utilities Network system requested works associated with theApplicants Works;
Design After Diversity Maximum Demand kVA (ADMD); Current Earthing System (MEN or CMEN);Any special Conduit requirements including spares;Any special requirements for Bushfire Risk Areas;Other requirements (e.g. provisions for the future development);
and
Hard copies of feeder plans and GIS information as required.ETSA Utilities will from time to time have specific requirements for
placement of the electrical works that will be vested to ETSA Utilitiesand will inform the Designer of these requirements.
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The design contractor shall prepare an electrical design layout in a
form acceptable to ETSA Utilities. In accordance with Chapter 3.3 of the
SA Distribution Code, ETSA Utilities is not obliged to accept a design or
construction if it is not undertaken in such a manner that is compatible
with the ETSA Utilities Network.
5.2 Design Req uirem ents
The Designer needs to ensure the design addresses any requirement
associated with references in Section 3 of this document and also
consider any other standards/regulatory/obligatory requirements that
are relevant.
Consider risk impacts as a part of the design process. Refer toSection 7.3.8 in this document;
For any extension within an ETSA Utilities MEN earthing area toestablish the soil resistivity/earth resistance readings. Refer toSection 7.3.3 in this document;
Evaluate site plan details, services and their locations. Otherservices, their locations and specific clearance requirements must
be taken into account in designing the electrical infrastructure.
Refer to Section 7.3.6 in this document;
Transformer load and cable rating must not exceed values asstated in Section 7.2 and 7.1.1 respectively in this document;
Must acquire all necessary documents such as CouncilAcceptance, ETSA Utilities Approval and other Approvals as
necessary. i.e. DTEI;
Must consider all requirements specified in this and otherdocuments that shall be appropriate to a design;
It is the responsibility of the Applicant or an agent of the Applicanti.e. the designer to ensure that during the course of the project
that anything that impacts or changes the design of the Electrical
Works is reflected in a notification to all relevant parties including
the Network Project Officer. A Design revision will be required. For
more details refer to Section 6 Design Process in this document;
During For Construction stage, it is theBuilder/Contractor/Installers responsibility to verify the actual on-
site details, mark the changes and notify the designer to ensure
the As Constructed matches the electrical installation;ETSA Utilities may request additional data, which should includeengineering calculation sheets for pole strengths, footing details
and tension calculations for overhead lines and cable pull
tensions for underground lines;
Any non-standard design will require written approval by the ETSAUtilities Manager Engineering Standards and Regulatory Reset
(MES&RR); and
For multi stage URD/UID development a proposed high voltagenetwork design is required for all stages as a component of the
preliminary design submission for the first stage.
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5.3 Design Princ iples
5.3.1E Drawings
The design should reference a specific E drawing to ensure the right
assembly is ordered and installed. The relevant E drawing should be
referenced where there needs to a specific / specification /installation. An example is public lighting, overhead construction
assemblies or specific service pits or pillars.
5.3.2Contestab le Works
A designer needs to be aware that many designs for a Network
extension can be built by either ETSA Utilities or an accredited
external electrical contractor. The Works that an electrical
contractor can normally undertake is limited to new installations that
are remote (not connected) to the ETSA Utilities Network. The
relevant ETSA Utilities Manager will be able to inform you of theextent of work a contractor can undertake.
A design can include a mix of contestable and non contestable
work and there may be works that ETSA Utilities needs to undertake
during the construction to assist the Contractor, i.e. access into an
existing transformer or switching cubicle for a cable installation.
The design needs to specify the extent of works that can be
undertaken by a contractor and the extent of works that can only
be undertaken by ETSA Utilities.
Where a Network Access Permit (NAP) is required and work needs to
be undertaken by ETSA Utilities during the construction phase the
design needs to be labelled with a unique identifier.
NAP 1, 2, 3 etc is the unique identifier for each specific accessrequest location. For some projects, i.e. a URD there may be a
number of NAPs required. Each one must detail the work to be
carried out and who undertakes the work. It is preferable that the
information is linked and close to the identifier.
The designer also needs to highlight the works to be undertaken at
the connection point(s) by ETSA Utilities. This level of detail assists in
scoping, costing and delineates responsibilities.
NAP 1 NAP 2
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5.3.3Underground Residentia l Deve lopment (URD)
A URD is a multi lot Torrens Titled development that can front a road
reserve or be contained within a Greenfield site with created roads.
Council can specify that an area is to be an underground
development within its approval process.
The design is based on the Network Specification that will specify the
After Diversity Maximum Demand (ADMD), supply point(s) and any
other specific requirements that ETSA Utilities may require.
While any industrial or commercial load, i.e. school, shopping centre,
office complex, etc, within the development may be treated as a
separate project it can be advantageous from a costing perspective
to incorporate the installation of cables and equipment into the
overall URD layout.
Please discuss a URD with a mix of residential and commercial
allotments with the relevant ETSA Utilities Manager.
Refer to TS -101 Pub lic Lighting Design Sta ndard for Underground
and Overhead Networks for public lighting options.
It is paramount that Council receives and accepts the form NICC -
451 Council Design and Public Lighting Agreement Document at
the preliminary design phase as a Council can have specific public
lighting requirements.
5.3.4Industrial Deve lopment
An Industrial Development is a multi allotment Torrens Title industrial
or commercial subdivision that will be sold on the open market. The
electrical installation can be with overhead or underground mains.
Council can specify that an area is to be an underground
development within its approval process and can also specify that
each allotment is serviced.
There shall be two levels of installation that ETSA Utilities will in general
consider. The designer needs to verify with the Applicant the level of
servicing that is required.
5.3.4.1 A Service d Industrial DevelopmentA design needs to encompass the agreed supply loads
within the Development.
If the load requirements within the development are
unknown, ETSA Utilities will accept a design for the
electrical infrastructure in a commercial or light industrial
area and that provides the following:
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Generally a minimum of an 80 ampere three phaseservice for each allotment;
Installation of additional spare conduits to meet thecapability of accepting a future 11kV supply upgrade to
every allotment;
Transformer(s) capable of handling the agreed loadcapacity; and
Public lighting in accordance with Council and theapplicants requirements.
5.3.4.2 A Service ab le Industrial Deve lopmentA serviceable development design will encompass the
installation of a backbone high voltage cable network
within the subdivision, (but individual service points for
each allotment are not provided) additional spare
conduit installations for each property to assist in any
future servicing arrangement and public lighting inaccordance with Council and the applicants
requirements.
This design approach should be favoured if individual
customer characteristics are unknown, or if individual
customer loads have the potential to vary significantly. An
applicant is required to inform purchasers that the blocks
shall not be serviced but can be serviced at the
purchasers cost.
5.3.5Community Title
A Community Title residential or industrial/commercial development
is deemed to be one property and the basis for servicing is via a
single supply point. Where a development is of such a size that
multiple transformers are required a back up or looped high voltage
supply may be specified.
The method of supply for a residential Community Title development
is via a grouped metering arrangement with the Applicant being
responsible for low voltage supply within the development. Up to 18
residential meters per group meter board is acceptable before asecond board will be required. The group meter board must be
located on common land.
Refer to the ETSA Utilities Service and Installation rules for more
information on a metering location.
A multi dwelling development on one title, i.e., a retirement village
can be designed utilizing the same design principle. As some
community titled developments can be gated it is important that the
designer ensures the ETSA Utilities requirement of access over a full
24hour period is achieved.
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5.3.6Redeve lopm ents
A redevelopment (sometimes called a Brownfield development)
encompasses an area which has, or had, an existing electrical
distribution infrastructure designed to supply power to a customers
metered supply point. The extent of a redevelopment will vary. Some
examples:
A total redevelopment site which will require the existing ETSAinfrastructure to be removed. An underground system will
generally replace the old asset;
A partial redevelopment with a mixture of old and newinfrastructure; and
Allotment layout changes only and the existing infrastructureremaining.
A redevelopment design needs to capture the extent of the works tobe undertaken, particularly in reference to the limitation of
contestable works on existing assets. Refer to Section 5.3.2
Contestable Works in this section.
5.3.7 ETSA Designer Ac c reditation and Intellec tual
Property
An External designer needs to be accredited prior to ETSA Utilities
issuing a Specification Compliance. The requirements are
documented in NICC 401 Information on Network Design and
Insta lla tion b y a n External Contrac to r .
The utilisation of any ETSA Utilities specification for any electrical
installation other then an installation designed to be vested and
connected to the ETSA Utilities Network without our approval is an
offence. ETSA Utilities views such misuse seriously and will take legal
action for any breach.
If a designer wishes to utilise an ETSA Utilities Specification for a design
that is not being vested to ETSA Utilities please contact the ETSA
Utilities Manager Engineering Standards and Regulatory Reset
(MES&RR) on 8404 5077 to discuss an agreement.
5.4 Design Drawing Prep aration Req uirem ents
The layout is to closely replicate a relevant standard ETSA drawing
sheet. The Network Project Officer (NPO) is to be consulted for advice if
the required drawing layout is uncertain. The design shall include the
following:
Drawing Title; Designer details in the bottom right hand side of thedrawing sheet above the drawing sheet details;
Single Line Diagram (SLD) of the proposed high voltage extension;
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Access permits points shall be numbered and the extents of theContractor works and ETSA Utilities works must be fully detailed.
Refer Section 5.3.2;
Easement location(s) utilising a dashed line. It is not essential thatthe easement is to scale. The width must be dimensioned and
depth when appropriate, i.e. transformers, switching cubicles,centre line of cables;
North Point Top right side of drawing, oriented between 9 and 3Oclock;
Bar Scale, Written Scale and Sheet Size;Road and Street Names, Street Numbers and Lot Numbers where
available;
DCDBs Plan Parcel Identification Numbers(for country areas);Suburb/Town Name/Hundred (for country areas);Standard Symbols and Styles as per the Caddsman Line design
package Refer to AppendixC for the required ETSA Utilities
standard drawing symbology;Legend describing only the symbols and line styles used on thedrawing;
Standard notes to conform with the purpose of the drawing andprovide relevant background information;
Feeder Plan Reference; Grid Reference in GDA94 MGA projection(easting and northing) for the centre point of each design
drawing sheet;
AMG Map Reference - e.g. 6628-41-VI; Filing Reference whereapplicable - e.g. A08 (local reference);
Drawing Number (CS or AW Notification number; CAD file to benamed with to this number also); Reference Drawings Noted;The scope of works to be undertaken by ETSA Utilities;
Cross Sections to comprehensively provide trenching detail, assetdepths and conduit use for underground installations;
Transformer details showing high and low voltage arrangements(padmount transformers only); Switching Cubicle details showing
high voltage arrangements;
Applicants Name; Development Number and Name (ifapplicable);
Asset ownership details;Drawing status (e.g. Preliminary, For Construction, As Constructed);Revision Identifier, Description, Reviser and Revision Date;Project name and ETSA Utilities project managers name;Construction completion date on As Constructed drawings with
details of constructor if it is not ETSA Utilities;
Dimensioned positions and alignments of installed or altered ETSAUtilities assets and identification of abandoned and removed
assets (on As Constructed drawings); and
Identification of all open points between low voltage transformerareas.
The initial preliminary design is to be submitted to ETSA Utilities relevant
PM/NPO as stated in Section 6.5.
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5.5 Spec ific ations for CAD Layering and Styles
The design CAD file must be compatible with ETSA Utilities systems and
processes including (but not limited to) checking, verification, archiving,
analysis and planning requirements. For this purpose, the design data
must meet the following criteria when imported into ETSA Utilities'
Caddsman CAD software:
The design data and subdivision layout must be drawn using truemodel distances in CAD (1:1 scale) and the correct plotting scale
(e.g. 1:500) must be set and displayed on the drawing sheets
along with bar scales and sheet sizes;
The symbology, line styles and colours used to display the designdata must appear the same as if the design was produced by
ETSA Utilities using CAD and the URD application software. Refer to
Appendix C for the required ETSA Utilities standard drawing
symbology; and
The different CAD data classes must be displayed on separatelayers (see Appendix B B-Sht 1 - for the Caddsman Line Design
Layer Convention as an example). A layer index must be included
on a separate layer that is invisible and excluded from plotting
(while retaining the option to activate the layer for viewing or
plotting if necessary).
ETSA Utilities reserves the right to reject any outdated, non-compliant or
non-compatible design data and to require revision and re-submissionof the data in a form acceptable to ETSA Utilities.
5.6 Spec ific ation for Elec tronic File Format
Where possible the design CAD file which is supplied to ETSA Utilities
must be in Caddsman format (versions 4.4 to Modeller SJ acceptable).
For requirements regarding the Non-Caddsman electronic files refer to
Section 5.7 - Spec ifica tion fo r Non-Ca ddsma n Elec tronic File Format.
5.7 Spec ification for Non-Ca ddsman Elec tronic File Forma t
Where it is not possible to supply electronic files in Caddsman format(versions 4.4 to Modeller SJ), the electronic file should be supplied in
*.dxf or *.dwg format provided that the file format version is compatible
with Caddsman Modeller SJ software. To meet this requirement, the
following is a suggested guide for consultants converting files from
AutoCAD.
All information for each drawing shall be contained within a single file.
This means that where the consultant has employed a combination of
paper and model space such that the drawing sheet and main body
of the drawing must be contained in separate files, the files shall be
merged together such that drawing in its entirety is contained in asingle file in model space.
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The drawing shall be reduced to basic elements such as lines, curves
and text. This means that where the drawing contains complex
elements such as blocks or dimensions, the associations between the
elements shall be dropped (e.g. in the case of blocks, the blocks shall
be exploded).
Where the drawing is in *.dwg format it shall be saved as an AutoCAD
version between releases 7 and 2005 inclusive. Where the file supplied is
a *.dxf file, the file must be similar to those created from AutoCAD
releases 7 to 13. Where a file conversion is attempted from any other
format such as MicroStation or CivilCAD the principles of file conversion
indicated above shall be adhered to.
Any files or entities linked to the CAD drawing (e.g. font files, pattern
files, symbols, Xrefs) must be included with the submitted CAD drawing
so that it can be viewed and plotted in its entirety without requiring any
significant re-linking or reconstructive work when received by ETSAUtilities. Packaging the CAD file and the associated linked files into a
*.zip file for submission is recommended.
For further information regarding ETSA Utilities electronic file
requirements, first consult the relevant Network Project Officer (NPO).
The NPO should seek further consultation from ETSA Utilities Facilities
Records Co-ordinator (FRC).
6. DESIGN PROCESS
There are three stages to a design, each serving a function as a project movesthrough from concept to completion. The Electrical Constructor is reliant on the
design being correctly labelled and approved.
6.1 Preliminary Design Req uirem ents
The initial drawing that needs to be submitted to the Network Project
Officer (NPO) must be marked as a Preliminary Drawing only. This shall
be placed in a prominent box near the title block, as a watermark
across the design or in the revision box at the bottom lefts side of the
sheet.
At this point the design can be issued to the Applicant for approval, to
key stakeholder parties for notification of pending work for
comment/approval and for external consultation.
Where Council and DTEI have an interest, the design needs to be
submitted with the form NICC-451 Counc il/ Department of Transport,
Energy and Infrastructure (DTEI) Design and Pub lic Lighting Ag reeme nt
Document for approval/acceptance if there are Works within a road
reserve or any public lighting installations within a road reserve.
The Network Project Officer (NPO) will verify that the design addresses
any specific requests issued in the ETSA Utilities project specification and
satisfies other ETSA specifications.
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6.2 For Construction Design Requirements
The designer can issue a For Construction design only upon receipt of
the Specification Compliance from ETSA Utilities. The Specification
Compliance confirms the following have been satisfied:
Any non-standard design arrangement is approved;Council/DTEI has accepted/approved the works in any road
reserve and any public lighting installation and tariff and ETSA is in
receipt of that agreement;
The offer has been signed and accepted by the customer; andAny easement requirement is either lodged with the LTO or ETSA
Utilities is in receipt of an Agreement to Grant an Easement. (Refer
to TS -102).
It is the responsibility of the design contractor to ensure that all the ETSA
Utilities specification requirements shall be met. The preliminary design isevaluated against the specification for compliance. This initial
evaluation is a component of the specification, administration and
inspection fee.
A non compliance will be issued if the design does not meet
specification. ETSA Utilities may issue a charge for any specification re-
compliance that is required.
The Authority to Proceed - Construction confirmation letter and the
Specification Compliance to the Applicant/s agent is the signal to an
electrical contractor and the customer that the relevant checks andapprovals have been completed. The Designer needs to be in receipt
of the Specification Compliance letter prior to marking a design as
approved with the notation For Construction.
6.3 As Construc ted Design Req uirem ents
The As Constructed drawing is a critical document that is a
prerequisite to ETSA Utilities accepting the Certificate of Electrical
Compliance and ultimately undertaking the vesting and connection.
The As Constructed drawing must be an accurate record of the
completed construction/installation including all of the changes
agreed to and signed off by the Network Project Officer/Project
Manager.
For most projects the As Constructed Drawing can be prepared well
in advance of the final electrical tests. The relevant number of As
Constructed drawings must be on site at the time the tests are
witnessed by the Compliance Officer. Refer Section 6.5.3 and Appendix
- E Issuing Proc ess fo r Design Drawing in this document.
The drawings will then be installed in all relevant ETSA Utilities plant to
assist ETSA Utilities personnel in the switching and customer connection.
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The legend and feature symbology should remain as proposed
however any proposed references must be removed from the title
block. The design must be prominently marked As Constructed and
the change to As Constructed status must be included in the revision
block.
The As Constructed design drawing shall comply with the relevant
specifications detailed throughout this Standard (e.g. Section 5.4), with
particular regard to the following:
Public roads MUST have street names in place at this point;All joints and equipment positions (high and low voltage) must be
accurately located and dimensioned;
Earth stake locations external to equipment must be clearly shownand dimensioned;
Any easement has critical location dimensions included on theexpanded easement diagram and/or main design;The primary electrical Contractors name must be included, e.g. inthe notes section; and
The date of completion.It is important that ETSA Utilities has all the relevant data on the
constructed Works. ETSA Utilities will only accept the Certificate of
Electrical Compliance if the As Constructed design reflects the
installations and the required copies have been forwarded to ETSA
Utilities. Refer to Section 6.5.
6.4 Revisions/ Cha nges to a Design
Any changes to a design (other than minor deviations) must be
submitted to the Network Project Officer for approval. Minor changes
will not necessarily require a For Construction drawing to be revised
on the proviso that all changes must be incorporated into the As
Constructed design and have been approved.
The relevant ETSA Utilities Network Project Officer/Project Manager is to
be consulted to resolve any uncertainties regarding incorporation of
changes into the design drawing. Designer must be aware that any
changes/revisions made to the Preliminary, For Construction andAs Constructed design will be in accordance with the following
requirements:
All design changes impacting on the design drawing shall beincorporated into the Master Design Drawing. The Revision
Identifier, Description, Reviser and Revision Date must be logged in
the revisions block for a minimum of the last five drawing revisions;
All revision details shall be clearly and unambiguouslymarked/specified (e.g. public light changes, additional cable
installations, additional road crossings, high voltage cable loopsinto easements etc.);
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Changes to earthing requirements shall be clearly detailed. (e.g. ifchanged from CMEN to MEN or vice versa);
Where it may not be possible to singularly itemise all changes as adesign moves from a Preliminary design to a For Construction
design, the critical changes and particularly the ones that may
impact any quotation (remembering that the Preliminary designmay have been released for quoting purposes), must be noted;
and
Revised drawings must be issued to ETSA Utilities as stated infollowing Section 6.5 - Proc ess for Issuing a Design Drawing in this
document.
6.5 Proc ess for Issuing a Design Drawing
An outdated or unapproved design can result in equipment ordering
and installation errors, increased risks, introduction of life threatening
hazards or significant additional cost variations. Design changes mustbe clearly and correctly communicated to ensure that all relevant
parties shall be working with the correct information.
The designer must ensure that all relevant parties shall be in receipt of
the latest information and drawing, throughout the life of the project
(i.e. Preliminary, For Construction, As Constructed stages including all
revisions made during these stages), by following the design drawing
issuing process.
Refer to Appendix - E Drawings Issuing Flow Chart for the details.
6.5.1Designers Role
It is the Designers responsibility to ensure that design drawings shall
be issued to all relevant parties (as specified below) upon revision of
the design drawing.
Forward a hard copy or PDF file at the Preliminary Stage toETSA Utilities NPO/ PM;
At the For Construction and As Construc ted stages,forward(1 Electronic CAD file + 1 PDF format copy) to ETSA Utilities
relevant NPO/ PM; and
Forward Copies (Numbers as required) either via Email or ashard c opies appropriately to all other relevant recipients.
Refer to Appendix - E Drawings issuing Flow Chart for thedetails.
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NOTES:
If submission of an electronic CAD drawing is not possible viaemail then submission of the CAD drawing on Data Disks should
be permitted. Data Disks must be clearly labelled as specified in
Section 5 in this document and must contain a PDF copy of thedrawing; and
If an ETSA Utilities NPO/PM or any other responsible ETSA UtilitiesOfficer is acting as Designer then they must also fulfil the
Designers role in the issue of drawings.
6.5.2Network Projec t Offic ers/ Projec t Ma nagers Role
On receipt of new or revised design drawings from the Designer, It is
ETSA Utilities NPO/PMs responsibility to ensure that design drawings
shall be further issued as specified below:
Forward a hard copy or PDF file at the Preliminary Stage toETSA Utilities Fac ilities Rec ords Co- ordina tor;
During the For Construction and As Constructed stagesforward 1 Electronic CAD file + 1 PDF format copy via CCADDDS
to ETSA Utilities Facilities Records Co-ordinator. If CCADDDS is
not accessible the files should be sent via email/internal mail;
and
1 Hard c opy (at the Preliminary and at the For Constructionstages) and 2 Hard copies (at the As Constructed stage) to
the ETSA Utilities Comp lianc e Co-ordinator.
NOTE:
It is the specific requirement of Facilities Records that they mustbe in receipt of the latest drawing revision throughout the life of
the project.
6.6 Plan of Division Changes
If the position of any transformer/switching cubicle or underground
cable is to be altered at any time during the design process or the
execution of the Works, the survey plan must be amended to reflect the
change and satisfy the requirements in TS-102 - Easement Sta ndard fo r
Distribut ion Networks.
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7. HIGH VOLTAGE NETWORK
7.1 High Voltag e Ca bles Selec tion
Cable sizes will be based on the summation of the nameplate rating of
individual padmount transformers in a loop system while also taking into
consideration extended high loading during summer periods (Refer toSection 7.1.1 in this document for more details). If future expansion is
expected, then 300mm2 cable will be the minimum size.
Refer to Appendix D: D-Sht 1 - Typica l Underground High Voltag e
Circ uit Diagram in this document as a reference for an explanation of
various scenarios in making an underground high voltage cable
selection. Where cabling space is restricted, the following 6.35/ 11kV
cables shall be used in the CBD and Comm ercia l/ Industrial
Developments:
TABLE 1: Cable Sizes for 6.35/11kV in CBD and with approvalCommercial/ Industrial Develop ments:
Cable Desc ription: ETSA Utilities Supply Item Nos.
6.35/ 11kV Al. Cond . Cu. Cond .
240mm2, 3c, XLPE/HDPE
Individual Cu Screens-- CK3240
185mm2, 3c, XLPE/HDPE
Individual Cu Screens-- CK3185
The following 19/33kV cables shall be used in the CBD and
Commercial/Industrial Developments:
TABLE 2: Cable Sizes for 19/ 33kV in CBD and with approvalCommercial/ Industrial Develop ments:
Cable Desc ription: ETSA Utilities Supply Item Nos.
19/ 33kV Al. Cond. Cu. Cond.
240mm2, 1c, XLPE/HDPE, Cu Screen -- CK8240
70mm2, 1c, XLPE/HDPE, Cu Screen -- CK8070
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TABLE 3: Ca ble Sizes for 11kV New URD Residential Land Divisions:
Purpose: Cable Desc rip tion:ETSA Utilities
Supply Item
Nos.
11kVAl.
Cond.
Cu.
Cond.
630mm2, 1c, XLPE/HDPE, Cu Screen;
ORCK6039 --11 kV Substation Feeder
Exits to the
First Switching Cubicle 630mm2, 1c, XLPE/HDPE, Cu Screen -- CK6050
630mm2, 1c, XLPE/HDPE, Cu Screen
(Backbone);
OR
CK6039 --
Main Feeders from theFirst Switching Cubicle300mm2, 1c, XLPE/HDPE, Cu Screen
(Not Bac kbone)CK6025 --
Main Feeders Connecting
Padmount Transformers300mm2, 1c, XLPE/HDPE, Cu Screen CK6025 --
Substation Ties Between
adjacent 11kV feeders.
(Start and End of Feeder)
630mm2, 1c, XLPE/HDPE, Cu Screen CK6039 --
630mm2, 1c, XLPE/HDPE, Cu Screen;
ORCK6039 --Substation Ties Between
adjacent 11kV feeders.
(at the Open Point) 300mm2, 1c, XLPE/HDPE, Cu Screen CK6025 --
95mm2, 1c, XLPE/HDPE, Cu Screen;
ORCK6005 --
Looped Cables
within a Feeder 95mm2, 3x1c, Bundled XLPE/HDPE,
Cu Screen
CK6006
(Triplex)--
630mm2, 1c, XLPE/HDPE, Cu Screen;
ORCK6039 --
11kV Feeders Backbone to
End of Feeder
300mm2
, 1c, XLPE/HDPE, Cu Screen CK6025 --
95mm2, 1c, XLPE/HDPE, Cu Screen,
ORCK6005 --
Laterals and Radials95mm2, 3x1c, Bundled XLPE/HDPE,
Cu Screen
CK6006
(Triplex)--
NOTES:
Equivalent Copper (Cu) sized cable can be used.Refer Appendix - D - Typ ic a l UG HV Circ uit Diagram
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7.1.1Underground HV XLPE Insula ted Ca ble Ratings
Designers shall ensure the maximum operational ratings of cables
shall not be exceeded. Particular attention shall be given to
Extended high load ing during summer periods (i.e. Summ er
Emergenc y Rating) for any given cable in determining cable ratings.
Designers shall calculate using an appropriate de-rating formula
based on the following parameters and/or actual specific criteria
which will include but not be restricted to:
Soil thermal resistivity:1.2 C m/W for summer emergency continuous rating; and0.9 C m/W for winter emergency continuous rating.
NOTE:
Where practicable soil thermal resistivity testsshould be done for direct buried applications.
Spacing of cables:100 mm for horizontal formation; andTouching for trefoil formation.
Ground temperatures:25 C for summer; and12 C for winter.
Conductor (maximum) XLPE insulation temperature:90 C for normal conditions; and120 C for emergency conditions.
Cable burial depth:910 mm.
Number of circuits;Direct buried versus conduited systems; and
Heat from nearby cables/circuits.IEC 60287 and AS/NZS 3008.1.1 explain the cable rating calculation
method and Cable manufacturers data should also be referred to.
For further information on cable rating requirements consult ETSA
Utilities relevant Project Manager/Network Project Officer.
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7.2 Design Consideration for a Transformer and Switc hing
Cubicle
The Padmount Transformer and Switching Cubicle (RMU) with technical
specification/rating stated in section 7.2.1 and 7.2.2 shall also be
suitable for continuous trouble free operation when subjected to theenvironmental operating conditions.
The environmental operating conditions stated below shall be not
restricted to and should be used as Guide only:
Installation: Outdoor/Indoor;Sola r Radiation: Up to 1.1kW/m2;Max. Altitude/Site Elevation (above mean sea level): 1000m;Ambient Air Temp.: From - 5C to + 50C and Max. 24hr avg. 40C;Black Body Temp. in Sunlight: 85C;Max. Temp. inside Enclosure: 65C;Dust: Concentrations Up to 10g/m;Humidity: Max. relative humidity up to 90% over 24 hr periods; andPollution: Areas of coastal spray and medium level industrial
pollution with equivalent salt deposit density up to 30mg/m2 per
month.
When an electrical design does not satisfy the specification/rating
requirements, the design must be assessed by ETSA Utilities and a
dispensation should be given in writing from the relevant ETSA Utilities
NPO/PM.
7.2.1Padmount Transformer Spec ific ation/ Rating:
Transformer specification/rating must be capable of supplying the
maximum customer demand during extreme heatwave conditions.
The Transformer load (specified kVA multiplied by the number of
customers) must not exceed:
85% of the name plate cyclic rating of the transformer wherethe transformer installed supplies more than one customer; and
100% of the name plate cyclic rating of transformer only for aSingle Commercial/Industrial customer installation, on the
proviso that all customers installations that shall be connected
to this transformer have been fitted with a load limiting control
device equivalent to the agreed service capacity as per the
ETSA Service and Installation Rules 6.7.2.1.
For a URD, the Transformer Size shall NOT exceed 300kVA and
associated cable ratings must also be taken into consideration.
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7.2.2Switching Cubic le (RMU) Spec ification/ Rating:
Switching devices within a Switching Cubicle (RMU) must be graded
to offer protection for the ETSA Utilities infrastructure under maximum
demand loadings, i.e. extreme heatwave conditions.
85% of the rated current of the switching device where theSwitching Cubicle is installed and exposed to the direct
sunlight.
7.2.3Underground HV Switching Point Requirements:
High voltage switching locations shall be determined such that the
maximum load switched at a given point shall not exceed the
capacity of the 3-phase ganged switch.
The maximum number of transformers between switching points shall
be limited to the load breaking capabilities of the switching devices
on the feeder.
In a high voltage looped system, the open point of the transformer
must have a provision for remote switching capabilities (i.e. remotely
operable Ring Main Unit (RMU)) in a transformers high voltage
compartment (or a Switching Cubicle).
A remotely operable RMU shall be used at all open points between
adjacent feeders.
NOTES:
All final high voltage open points using switches (as nominatedby ETSA Utilities) shall be at a transformer with a Ring Main Unit
(RMU) or a free standing switching cubicle (RMU) with a Load
Switch (LS);
All final feeder tie points (as nominated by ETSA Utilities) shallhave remote operation functionality i.e. switching cubicle
(RMU);
The use of a circuit breaker (CB) within a switching cubicle asan open point of any feeder backbone is NOT permitted; and
With a transformer, a transformer with RMU or a switchingcubicle, the following shall NOT be permitted as open points:
Circuit Breaker (CB);Fuse (F); andLoad Switch Fuse (LSF).
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Examples:Refer to Appendix D: D-Sht 1 - Typica l Unde rground High Voltag e
Circ uit Diagram for the explanation of following scenarios.
Sc ena rio 1: Looped Circuits on the same FeederIf the looped circuits shall be on the same feeder then there must be
an open point. At this open point the switches must be able to
operate remotely. To achieve this remote operating capability
either:
a RMU shall be installed at the padmount transformers highvoltage compartment; or
a Switching Cubicle (RMU) shall be installed nearby.Cables shall be a minimum size of 95mm2Al.
Sc ena rio 2: Looped Circ uits with an Open p oint
separating two main Feed ersIf the looped circuits with an open point separating two main
feeders then Scenario 1 condition shall apply except that cables
shall be a minimum size of 300mm2.
Sc enario 3: Radial CircuitsIt must be noted that for radial circuits, if any future
extension/connection is required then it shall be to the same existing
feeder. Where a radial circuit could become a looped circuit then
Scenario 1 applies.
Cables shall be a minimum size of 95mm2 Al.
7.2.4Transformer and/ or Switching Cubic le Loc ations
For a land development with multi customers a transformer location
must take into account the low voltage feeder distribution network
and be located as close as practicable in the centre of the load. If
this requirement is not satisfied then ETSA Utilities will not provide a
Specification Compliance for a design with a transformer location.
Where the customer is required to make provisions for the
transformer, switching cubicle and/or other service protection
devices, the position provided shall be free of obstruction and
access must be continuously available for ETSA Utilities to safely
operate on the device or devices at all hours.
The location of the padmount transformer must not breach the
requirements of relevant standards, environment and locations of
other services such as fire booster cabinets, water, sewer services
and infrastructure etc.
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A Designer must conduct a risk assessment prior to commencing any
design and follow the requirements as mentioned below:
Evaluate site plan details and establish where existing andproposed services shall be located in areas in the vicinity of
ETSA equipment;
Suitability of the terrain in the vicinity of any installation andfuture accessibility to ETSA equipment;
Eliminate equipment placement conflicts and any breach ofcompliance issues;
Assessments must be presented with the preliminary design;Vicinity of equipment nearby a watercourse addressed. (Refer
Section 7.3.8 in this document for the detail).
Equipment for a development or a single customer is only to be
installed in locations that allow ETSA Utilities to adequately access
the equipment. ETSA must have access to a transformer, switching
cubicle and a service pillar at ALL times i.e. 24 hours / 7 days a week
from the date of energisation.
Equipment location should need to be located on a property
boundary facing a road reserve to achieve this. Transformer and
switching cubicles can be sited on:
Reserves;Very large building allotments likely to be developed as high
density residential sites;
Local shopping centres; andAt the rear and side of residential corner allotments.
NOTE:
This equipment shall NOT be located in road reserves withoutconsultation from ETSA Utilities Network Project Officer/Project
Manager. NPO/PM will assist in seeking written approval from
Manager Network Asset (MNA).
Also refer to NICC 802 - 11kV to Low Volta ge Padmo unt Transforme rs
- Information and Requirements for Customers which provides
additional information for single customer transformer installations.
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7.2.4.1 Transformer and/ or Switching Cub ic le Setbac kDesigners need to be vigilant when selecting locations for
above ground equipment in developments, car parks and
private roadways, taking into account the boundary to
kerb dimension and final development
designs/environment.
For a Transformer and/or Switching Cubicle the following
design requirements shall be included:
A minimum set back of 1.0m from the back of a kerb andthe installation of bollards on any side exposed to
vehicular traffic;
The installation of bollards on any side exposed tovehicular traffic that does not have a suitable form of
protective device;
An exemption for bollard installation should be consideredfor set backs greater then 1.0m and will depend on
location, traffic and additional protective devices, e.g.
the installation of a 200mm high concrete kerb; and
On the proviso that the set back is 1.0m, a centre bollardin front of the doors is not required.
For further information on setback requirements please
contact and consult ETSA Utilities relevant ProjectManager/Network Project Officer.
7.2.5A Loop ed High Voltage Network
The installation of three or more transformers on a radial tee off will
require the extension to become a looped high voltage network. If a
multi stage development already has three transformers installed,
any future stage which increases that number must be a looped
network design.
Consideration should be given to a future looped system on theproviso there is a master-plan and staged construction proposal that
has written agreement from the ETSA Utilities relevant Project
Manager/Network Project Officer.
Any switching cubicle or transformer located in such a way that it
unnecessarily deviates the high voltage cable route and requires
additional lengths of high voltage cable will be deemed to be
installed at the request of the developer and at the developers cost.
Refer to Appendix D: D-Sht 1 - Typica l Unde rground High Voltag e
Circ uit Diagram.
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7.3 Other Considerations/ Req uirem ents
The site shall be well compacted. Any site that is not level as defined in
Section 3 of TS -085 should need a retaining wall.
E drawing E1982 sheet 3.3 specifies that the height from the ground
level to the top of the pad base shall be 75mm and E1981 sheet 3.0
specifies 150mm for a switching cubicle vault. This is to ensure the
switchgear and fuses shall still at the correct height for operational
purposes and the vault is not compromised.
7.3.1Ferroresonance
When designing a high voltage network, consider the possibility of
ferroresonance occurring due to the combination of underground
cables and a transformer. To eliminate the likelihood of ferroresonant
over-voltages, 3-phase Ganged Switching Devices (i.e. Load Switch
(LS)) must be used at all switching points.
For various 3-phase Ganged Switching Device arrangements refer to
appropriate E-drawing as per Manual No. 4 - Underground
Constructionand for over to under on the pole type arrangements
refer to Manual No. 3 - Overhea d Construct ion.
7.3.2Surge Arrestors
Surge Arrestors shall be required for protecting primary plant against
damage from lighting and/or switching overvoltage. For over to
under (O/U) cabling arrangement, surge arrestors shall be installedon any over to under (O/U) pole.
7.3.3Earthing (Grounding)
For an MEN earthing area, the designer needs to arrange for soil
resistivity/earth resistance tests. The design needs to consider these
tests in relation to the minimum readings required at the time of
installation and factor in earthing standards as stated in E-drawing E-
1905 series, relevant E-drawing manuals and AS/NZS 3000.
For sites with difficult earthing conditions, the design shall considerthe location of equipment and the installation of additional earthing
facilities. Additional earthing facilities can be achieved in a number
of ways and there are specialist firms that can provide advice.
7.3.4Cable Numb ering System
The layout plan must detail a switching cubicle and a padmount
transformer showing high and low voltage cable destinations and
labelling/numbering showing the destination of each exit that must
satisfies the protocol specified in TS-105 Section 5. ETSA Utilities
approved symbols for feeder equipment must be used.
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7.3.5Underground Cabling Detail
The Designer will need to consider the level of detail needed for a
conduit and cable installation. Complex installations will need to be
detailed in cross sections at various points along the common service
trench (CST) route.
7.3.6Clearanc e to Other Servic es
It is the designers responsibility to take into account the safe
clearance from other services. For the vertical and horizontal
separation between other services such as Gas pipes, SA Water,
Telecommunications Services, Private Sewer/Water etc. Refer to TS
085 - Trenc hing a nd Cond uit Sta ndard fo r Underground Ca b le
Networks or contact the relevant authority if confirmation is
required.
As an example AS 2419.1-2005 Fire Hyd rant Insta lla tionsSyste m
Design, Installation and Commissioning, specifies a minimum
requirement for the location of fire hydrants from any high voltage
electrical distribution equipment to be 10m. For the consumers
mains clearance/installation requirements refer to Service and
Installations Rules and AS/NZS 3000.
7.3.7Easem ent Req uirem ent
Easements shall be required for ETSA Utilities equipment. Details
concerning easements are contained in the Technical Standard TS
102 - An Easem ent Sta ndard for Distribution Netw orks. Alleasements shall be indicated on the design drawings as
enlargements showing all dimensions and appropriate cadastral
information so that the surveyor for the Applicant can include ETSA
Utilities easement requirements on the Final Plan for the Land Division.
7.3.8Infrastructure Risk Assessment Requirem ent
The Designer is to provide a risk assessment matrix report as a part of
a specification compliance requirement.
The assessment needs to consider but is not limited to the following:
Access for operational purposes;Future removal and installation;Equipment failure impact on surrounds; Impact on third party equipment installation in the vicinity; andSoil contamination in relation to open trenching within private
property as referred to in TS-085, clause 14.
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When a proposed transformer site is in the vicinity of a watercourse
(refer Section 4 for the definition), as defined in the Environment
Protection (Water Quality) Policy 2003, under the Environment
Protection Act 1993, and the results of the risk assessment are high
with significant consequences, then either of the following
alternatives shall be adopted:
Relocate the transformer site; or Install an oil containment type transformer (not dry type).
The transformer type referred to above is a special order item. For
details, contact the ETSA Utilities Manager Engineering Standards
and Regulatory Reset (MES&RR). For resolving environmental related
issues, first consult the relevant Project Manager/Network Project
Officer. The PM/NPO should seek further consultation from ETSA
Utilities Environmental Management Team.
8. LOW VOLTAGE NETWORK
8.1 Low Voltage Cables Selec tion
The following 0.6/1.0kV cables shall be used for the low voltage
network.
TABLE 4: Cable Sizes for Low Voltage Ma ins:
Cable Desc ription: ETSA Utilities Supply Item Nos.
0.6/1.0kV Low Voltag e Al. Cond . Cu. Cond .
150mm2, 4c, XLPE/HDPE
(Bundled, Termite Resistant)CK5310 --
TABLE 5: Cable Sizes for Low Vo ltage Mains - CBD Ap plications:
Cable Desc ription: ETSA Utilities Supply Item Nos.
0.6/1.0kV Low Voltag e Al. Cond . Cu. Cond .
70mm2, 4c, PLY/HDPE;
OR
70mm2, 4c, XLPE/HDPE
--
CW1070;
OR
Non-Stock**
185mm2, 4c, PLY/HDPE;
OR
185mm2, 4c, XLPE/PVC
--
CW1185;
OR
CK1185
240mm2, 4c, XLPE/PVC -- CK1240
300mm2, 4c, PLY/HDPE;
OR
300mm2, 4c, XLPE/HDPE
--
CW1300;
OR
Non-Stock**** = Refer to E4020 Sheet 2 for the details.
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TABLE 6: Cable Sizes for Low Voltage Servic es - CBD Ap plications:
Cable Description: ETSA Utilities Supply Item Nos.
0.6/1.0kV Low Voltag e Al. Cond . Cu. Cond .
25mm2
, 4c, PLY/HDPE -- CW1025
TABLE 7: Cable Sizes for Low Volta ge Public Lighting Applications:
Cable Desc ription: ETSA Utilities Supply Item Nos.
450/750V Low Voltag e Al. Cond . Cu. Cond .
2.5mm2, 2c, PVC/PVC
(Red/Black cores-White sheath)-- CD7240
6.0mm2, 2c, PVC/PVC
(Red/Black cores-White sheath)-- CD7253
6.0mm2, 1c, PVC/PVC
(Green/Yellow cores-Black sheath)-- CD7061
8.1.1Underground Low Voltage Cable Rating
Refer to Section 7.1.1 in this document for design factors fordetermining de-rating factors for any cable. Designers must ensure
the maximum operational ratings of underground low voltage cables
shall not be exceeded and provision for spare capacity is included
for any foreseeable demand requirements.
IEC 60287 and AS/NZS 3008.1.1 explains the cable rating calculation
method. Cable manufacturers data should also be referred to. For
further information on cable rating requirements consult ETSA Utilities
relevant Project Manager/Network Project Officer.
8.1.2Low Voltage Parallel Cable TerminationParallel low voltage cables shall only be terminated in a Junction p it
of P7 size (or larger). The design needs to reflect the correct
installation. A service pillar is NOT suitable for terminating parallel low
voltage cables.
Where parallel cables shall be fed from transformers, they shall be
terminated at the 1st Junction Pit from the transformer of an
appropriate size to suit the application and the circuit shall be clearly
labelled Parallel Cables as per ETSA Utilities Construction E-drawing
E1921 Sheet 2.5 and 3.20.
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8.2 After Diversity Maximum Dem and (ADMD)
The ADMD of a particular development shall not in general be less than
8 kVA per allotment. ETSA Utilities will specify the design ADMD as a part
of its specification. Refer to Appendix A, A-Sht 1 and A-Sht 2 for the
details.
The base ADMD specified by ETSA Utilities in a new housing
development specification will be based on the ADMD Table, Refer to
Appendix A-Sht 2 Tab le for ADMD for Averag e Dwelling Sizes .
House sizes from ETSA Utilities research are generally in the medium to
large range. From the Appendix A-Sht 2 Table this would indicate an
ADMD of 8 kVA.
The projected dwelling sizes for a development will be based on
previous stages or the standard of housing in the vicinity. Any variationto the specified ADMD will require approval by the relevant ETSA Utilities
Network Manager.
The designer must take into account:
The existing and proposed customers supplied from an existingtransformer;
The total proposed customers load on a proposed transformer,including customers within future stages and any reinforcement of
existing ETSA Utilities assets as specified by ETSA Utilities; and
The total proposed customers load on proposed low voltagecables, including customers within future stages and any
reinforcement of existing ETSA Utilities assets as specified by ETSA
Utilities.
The ADMD will apply to:
Voltage drop calculations;
Transformer load (specified ADMD multiplied by the number ofcustomers) which must not exceed values as stated in Section 7.2
of this document; and
Cable ratings (specified in Amperes) which must not exceed thevalues stated in current AS/NZS 3008.1.1 at a conductor
temperature of 90 C. The expected load on a cable is to be
determined from the specified ADMD multiplied by proposed
numbers of customers connected to that cable.
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8.3 Underground Low Voltage Drop
The voltage drop can be calculated using values supplied in Appendix
A, A-Sht 1 - Low Voltage Drop Tab le in Volts for (ADMD versus. Number
of Customers) and A-Sht 2- Tab le for ADMD for Average Dwelling
Sizes in this document.
For any underground low voltage feeder, the voltage drop shall NOT
exc eed 10 Volts:
to the last (farthest) connection point; andto the last (farthest) open point.
The voltage drop values for mains and services at the end of each low
voltage circuit shall be indicated on the design drawings. In some
circumstances parallel cables (i.e. 2 circuits of 150mm2 bundled cables)
can be used for reduction of voltage drop.
In such cases parallel cable details must be incorporated in the design,
refer to section 8.1.2 for the details.
8.4 Low Voltag e Balanced Loads
Single phase customers shall be evenly connected across all three
phases with their phase connection identified (i.e. red (R), white (W) or
blue (B)). The phase connections need to be Rolling e.g.
sequential/alternating.
Three phase customers shall have their loads evenly balanced across all
three phases. For URD designs, unless final customer details are known,
the design needs to take into consideration single phase connections.
8.5 Number of Low Voltage Feeders per Transformer
A maximum of 4 low voltage feeders shall be provided from each
padmount transformer. The arrangement of low voltage feeders will be
dependent on the physical arrangements of the development. The
number of customers (normally single phase) shall be balanced over
the three phases of each feeder.
The open points between all low voltage feeders shall be clearly shown
on the design drawing.
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8.6 Low Voltage Feeders Ties
Low voltage feeder ties shall be mandatory for a URD /UID low voltage
networks. The open point for such ties shall be clearly indicated on the
design drawing.
A tie should be achieved by running a length of 150mm2 Alum. low
voltage cable from one pillar to another with a suitable open point.
Where low voltage cables from different transformers come within 50m
of each other, the installation of a specific junction pit to achieve a tie
may be necessary to ensure that there is an open point and low
voltage switching capability.
A pit/pillar installation as per figure (1) is not necessarily required to be
at the end of a cable run. Refer to figure (1) for an example of a 3 way
low voltage feeder tie.
Figure 1: Example o f a 3 wa y Low Voltage Feeder Tie
In a high load area with a commercial component the installation of a
low voltage switching cabinet as per E1927 series drawings must be
considered for feeder interconnection. Refer to Sect