Cẩm Nang Thử Nghiệm Cáp Ngầm Trung Áp
Trang 1SA Power Networks
TECHNICAL STANDARD – TS-085
www.sapowernetworks.com.au
TRENCHING AND CONDUIT STANDARD FOR UNDERGROUND
DISTRIBUTION CABLE NETWORKS
Trang 2REVISION NOTICE:
May 2012
Clause 7.2.8 merged into clause 7.0
Updated clause 11.2 and added tables 3A & 3B
Updated clause 12.0, 17.12 and Appendices - C, H-1 and H-2
Clause 16.0 is moved and included as clause 8.8
Various tables consolidated for better readability
3 September 2012 Company name change only No other content of this Technical Standard has been
altered Any revision markings are from the May 2012 edition
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 54 091 142 380
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
CKI Utilities Development Limited, ABN 65 090 718 880
PAI Utilities Development Limited, ABN 82 090 718 951
each incorporated in The Bahamas
1 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
contained in this Technical Standard;
b Accept no liability for any use of the said information or reliance placed on it; and
c 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 You
must 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
Trang 3CONTENTS
1.0 PURPOSE 7
2.0 SCOPE 7
3.0 GRACE PERIOD 7
4.0 REFERENCES 8
5.0 DEFINITIONS 9
6.0 BACKGROUND 12
7.0 CUSTOMER’S RESPONSIBILITIES 12
8.0 CIVIL CONTRACTORS RESPONSIBILITIES 13
8.1 Access Permit Requirements 13
8.2 Safe Edge Shovel Requirements 13
8.3 Civil Works Notification Requirements 14
8.4 Civil Works Compliance Requirements 14
8.5 Civil Works Non-Compliance 14
8.6 Requirements of Changes to Civil Works 15
8.7 Directional Bore Drawing Requirements 15
8.8 Backfilling and Consolidation 15
9.0 RETAINING WALLS 16
9.1 General 16
9.2 Design Consideration for the Retaining Walls 16
9.2.1 Other Design Requirements 18
10.0 TRENCHING 20
10.1 General 20
10.2 Trench Requirements for Road Reserve/Crossing 21
10.3 DPTI Requirements for DPTI Controlled Roads 23
10.3.1 DPTI Open Shared Trenching Requirements 23
10.3.2 DPTI Trenchless Boring Requirements 23
10.3.3 DPTI Notification 24
10.3.4 DPTI Traffic Control Notification Process 24
10.3.5 DPTI Emergency Work Requirements 24
10.3.6 DPTI Maintenance Period Requirements 25
10.4 Public Road (Non DPTI Roads) Controlled by Council 25
10.5 Conduits within Railway Boundaries 25
10.5.1 Telecommunications Pilot Cable Only 26
10.5.2 Telecommunications Fibre Optic Only 26
Trang 410.6 Clearances between Services 26
10.6.1 Vertical Separation between Services 27
10.6.2 Horizontal Separation between Services 28
10.7 Changes in Levels and Directional Changes 29
10.8 Shared Trench Arrangement 30
10.8.1 Typical Shared Trench Cross Sections 31
10.8.2 Trenching for SA Power Networks Telecom Only 31
10.8.3 Typical SA Power Networks only Trench 32
10.8.4 URD Trench Design Requirements 32
10.8.5 Trenching for Retrospective (PLEC Schemes) 32
10.9 Reduced Cover Trenching 32
10.10 Underground Cables on Bridge Crossings 33
10.11 Pit Installations 33
10.12 Cable Location Markers 34
10.13 Trenchless/Directional Boring 34
10.13.1 Requirements for Directional Boring 34
10.14 Hydro Vacuum Excavation 35
11.0 CONDUITS and BENDS REQUIREMENTS 35
11.1 General 35
11.2 Spare Conduit Provision 35
11.2.1 Wherever an electrical cable is buried direct 36
11.2.2 When a cable is installed in a conduit 36
11.2.3 Road Crossings 38
11.3 Conduit Bend Requirements 38
11.4 Conduit Reinforcement 40
11.5 Conduit Sizes 40
11.6 Conduit Cable Entry into Service Pillars 43
11.7 Typical Over to Under Conduit Entry into Ground 43
11.8 Conduits Compliance to AS/NZS Standards 43
11.8.1 Identification of Conduit Sizes 43
11.8.2 Colour of Conduits/Couplings 44
11.9 Conduit for Directional Boring 44
11.9.1 Drawing Requirements for Directional Boring 44
11.10 Conduit Installation (for and up to 33kV) 46
11.10.1 General 46
11.10.2 Requirements for the Conduit Installation 46
11.10.3 Additional Requirements for the Conduit Installation 47
11.10.4 Sealing of Conduits 47
Trang 512.0 TRENCHING ON PRIVATE PROPERTY 48
13.0 TRENCHING FOR SINGLE CUSTOMER ON VERGE 49
14.0 EXCAVATION FOR VAULTS AND PIERS 49
15.0 BEDDING SAND FOR LESS THAN 66Kv 49
16.0 POLYMERIC CABLE COVERS / MARKER TAPE 51
17.0 66kV UNDERGROUND CABLE INSTALLATION 51
17.1 Introduction 51
17.2 66kV Design Information 51
17.2.1 Extent of 66kV Civil Work 52
17.2.2 66kV Cable Route Design Changes 52
17.3 66kV Cable Trench Dimensions 52
17.4 66kV Cable Separation from Other Services 52
17.5 66kV Directional Boring 52
17.6 Installation of (66kV) Conduits in Open Trench 53
17.7 Lubrication Points – 66kV 53
17.8 Laying 66kV Cables 53
17.9 Thermocouples – 66kV 53
17.10 Flowable Thermal Backfill in Cable Trenches – 66kV 54
17.10.1 Background Information on FTB 54
17.10.2 General Factors for FTB 54
17.10.3 Installation Requirements for FTB 55
17.11 Bentonite Mixture in Conduits – 66kV 55
17.12 Protective Cover Slabs – 66kV 56
17.13 66kV Sand Backfilling Requirements 56
17.13.1 Sand Backfill – 66kV 56
17.14 Cable Marker Tapes – 66kV 57
17.15 Cable Markers – 66kV 57
17.16 Pits – 66kV 57
17.17 Joint Bays – 66kV 58
18.0 CONTAMINATED SOIL 58
APPENDICES: 59
A: Civil Works Notification & Compliance 59
B: Cable Location Marking Drawings 60
C: Example of Directional Bore Drawing 61
D: Typical Shared Trench Arrangements 62
D-1 Cables Buried Direct – (Shared Trench) 62
Trang 6(In Footpath for Non DPTI Roads) 62
D-2: Cables in Conduits – (Shared Trench) 63
(In Footpath or Road Crossing for Non DPTI Roads) 63
E: Typical SA Power Networks Trench Only 64
E-1: Cables Buried Direct - (SA Power Networks Only) 64
(In Footpath for Non DPTI Roads) 64
E-2: Cables in Conduits - (SA Power Networks Only) 65
(In Footpath or Road Crossing for Non DPTI Roads) 65
F: Typical Reduced Cover Trenching 66
G: Typical SA Power Networks Telecomm Trench (Only) 67
H: Trenching on Private Property 68
H-1: Cables in Conduit Cable at 1.0m Cover 68
H-2: Cables in Conduit Cable at 750mm Cover 68
H-3: Cable Buried Direct at 1.0m Cover 69
H-4: Trench for Single Customer on Verge 69
J: Typical Trench Arrangements for 66kV 70
J-1: Typical Flat Arrangement – 66kV - Roadway 70
J-2: Typical Trefoil Arrangement – 66kV - Roadway 71
J-3: Typical Under Bore Arrangement – 66kV Cables 72
K: Typ Over to Under Pipe Entering Detail 73
Trang 71.0 PURPOSE
This Technical Standard specifies the standard trench, conduit, retaining walls and Civil
works requirements for a new or upgraded installation that will be a component of SA
Power Networks‟ distribution network
Once the scope for a trench, conduits, retaining walls and Civil works is determined, then
this technical standard will assist the Customer in the Civil component of electrical
works/network extension The construction could encompass a network extension, PLEC
projects, SA Power Networks‟ capital works, specific arrangements or customer works
These works could be on private property or on a public road verge
This standard will assist in clarifying the responsibilities of customers regarding
agreements, approvals, construction requirements and the SA Power Networks
requirements for “Civil Works Compliance”
The specification in this technical standard is applicable (but not limited) to all parties
involved in the activities of trenching, conduit installation, retaining walls and Civil
works associated with the underground installation or alteration of distribution cable
networks
This technical standard is to cover all underground trenching and conduit installations;
however, section 17.0 is an additional requirement for applications to 66kV underground
networks The appendices at the end of this document provides more detailed information
on trench arrangements, Civil Works notification and Civil works compliance and cable
location markers
The “Electricity (General) Regulations 1997”, other statutory authority requirements,
AS/NZS standards and the Building Code of Australia (BCA) are the basis of TS-085
For any situation that is not covered in this standard, the requirement of AS/NZS 3000
applies There may be additional requirements and specifications that are project specific
For further assistance/information concerning this technical standard, please contact the
relevant SA Power Networks‟ Manager This technical standard is available at the SA
Power Networks websites below:
Intranet website (Internal)
Internet website (External)
The maximum grace period acceptable by SA Power Networks for implementing this
Standard is 3 months from the date of publication All projects that are not in receipt of
“Specification Compliance” at the revised date of issue for this technical standard will
need to incorporate the latest requirements
This is applicable to both the design and construction phases of the project The validity
period for a “Specification Compliance” is 60 days On the expiry of a “Specification
Compliance”, any specification change without a documented exemption must be
incorporated into the design and construction of SA Power Networks infrastructure
Trang 84.0 REFERENCES
The following listed documents are for additional information It is advisable to refer to
the current publications before implementing them Other documentation may be required
on a project specific basis
For Civil Contractors conducting regular Civil works for any SA Power Networks
installations, there is a Civil Construction Manual – 40 available on request This manual
details many project specific aspects of Civil works that my not be detailed in this
standard
Essential Services Commission of South Australia (ESCOSA) Codes:
Essential Services Commission of South Australia (ESCOSA) Codes:
SA Electricity Distribution Code (EDC)
Energy Networks Association (AUS) Publications:
ENA NENS 03 - 2006 - National Guidelines for Safe Access to Electrical and Mechanical
Apparatus
ENA NENS 04 - 2006 - National Guidelines for Safe Approach Distances to Electrical
and Mechanical Apparatus
South Australian Legislation:
This technical standard does not necessarily align with AS/NZS Standards Australia
Environment, Heritage and Native Vegetation Protection Acts:
Environment Protection Act 1993
Environment Protection Regulations 2009
Aboriginal Heritage Act 1988
Native Vegetation Act 1991
Heritage Places Act 1993
National Parks & Wildlife Act 1972
Natural Resources Management Act 2004
AS/NZS ISO 14001:2004 – Environmental Management System Standard
Standards Australia Publications:
AS 60038 - Standard Voltages
AS/NZS 3000 - Electrical Installations (known as the AS/NZ Wiring Rules)
AS/NZS 1158 - Lighting for Roads and Public Spaces Set
AS 1345 - Identification of the Contents of Pipes, Conduits and Ducts
AS/NZS 2032 - Installation of PVC pipe systems
AS/NZS 2053 - Conduits and Fittings for Electrical Installations – Part 1 & 2 - General
Requirements
AS/NZS 2648.1 - Underground Marking Tape - Non-Detectable Tape
AS 2885.1 - Pipelines - Gas and Liquid Petroleum - Design and Construction
Trang 9 AS/NZS 3500 (Set) - Plumbing and Drainage Set
AS 3798 - Guidelines on earthworks for commercial and residential developments
AS/NZS 4645.3 - Gas Distribution Networks - Plastics Pipe Systems
AS/NZS 4130 - Polyethylene (PE) Pipes for Pressure Applications
AS 4678 - Earth-Retaining Structures
AS 4799 - Installation of Underground Utility Services and Pipelines within Railway
Boundaries
AS/NZS ISO 31000 - Risk Management - Principles and Guidelines
Note: AS/NZS4360 is superseded and replaced by AS/NZS ISO31000
ASTM STP1331-98 - The Design and Application of Controlled Low-strength Materials
(flowable thermal backfill)
ASTM STP1459-04 - Innovations In Controlled Low-strength Material
(Flowable thermal backfill)
AS/ACIF S009 - Installation requirements for customer cabling
(Telecommunications Wiring Rules)
WSAA Codes - Water Services Association of Australia:
WSA 02: Sewerage Code of Australia
WSA 03: Water Supply Code of Australia
SA Power Networks Documents:
Service and Installation Rules
Technical Standards
NICC Brochures
Guidelines for SA Power Networks Crossings of the Electrified DPTI Railway Network
Relevant E-Drawing Series; and
Civil Construction Manual – 40
AS/NZS – stands for Australia and New Zealand Standards published by Standards Australia
Authorised Person – the person in charge of the premises, or the registered electrical worker or
licensed electrical Contractor or other person appointed or selected by the person in charge of
the premises, to perform specific duties associated with the electrical installation on the
premises
Boring – refers to activities of directional drilling (typically horizontal or vertical)
Cable/s – a wire, conductor or form of material designed for carrying electric current or
communications signals, installed underground
Customer – has the meaning given to that term in the Electricity Act 1996, namely a person
who has a supply of electricity available from a transmission or distribution network for
consumption by that person and includes:
(a) The occupier for the time being of a place to which electricity is supplied;
(b) Where the context requires, a person seeking an electricity supply;
(c) A person of a class declared by regulation to be customers; and
(d) Customer may or may not necessarily be the landowner
Trang 10Customer Agents – Customer agents are parties representing the customers Such parties may
include registered electrical workers, licensed electrical Contractors, consulting engineers,
architects, and equipment manufacturers
CLER – stands for Customer Lighting Equipment Rate
DCDB – Digital Cadastral Database (DCDB) or landbase date is obtained from the S.A Govt
Department of Environment and Heritage The landbase data includes parcel shapes, parcel line work, parcel text, road centre lines, road names, suburb shapes, suburb text, Local Government Authority shapes and text
DPTI – Department of Planning, Transport and Infrastructure
Distribution Network – has the meaning given to that term in the Electricity Act 1996, namely
the whole or a part of a system for the distribution of electricity, but does not include anything
declared by regulation not to be a distribution network or part of a distribution network
For the purposes of these rules references to Distribution Network means the network poles,
wires, underground cables, padmount transformers, substations etc, operated by SA Power
Networks, which transports electricity from the transmission system to a customer‟s
Connection Point
Excavation Depth – is the vertical distance measured between ground level and the deepest
part of the excavation
(a) Electricity Infrastructure means – (b) electricity generating plant; and (c) powerlines; and
(d) substations for converting, transforming or controlling electricity; and (e) equipment for metering, monitoring or controlling electricity; and (f) any wires, equipment or other things (including tunnels and cavities) used for, or in connection with, the generation, transmission, distribution or supply or electricity
Excavation – refers to the activities of digging or trenching and can be by mechanical means or
by hand
SA Power Networks’ Manager – The SA Power Networks‟ Manager/Responsible Officer
serving that area of the customer‟s installation
Ground Level – is nominally the final level of the ground that SA Power Networks equipment
is to be installed at
High Voltage (HV) – For the purpose of this document shall mean a voltage exceeding 1,000V
A.C up to and including 33,000V A.C
Low Voltage or LV – For the purpose of this document shall mean a nominal voltage exceeding
50V A.C but not exceeding 1,000V A.C
MNSP – stands for SA Power Networks‟ Manager Network Standards and Performance
MNP – stands for SA Power Networks‟ Manager Network Planning
NA – stands for SA Power Networks‟ Network Assets
Trang 11NPO/NPM – stands for SA Power Networks‟ Network Project Officer/Manager
NPE – stands for SA Power Networks‟ Network Planning Engineer
NSP – stands for SA Power Networks‟ Network Standards and Performance Group
OTR – stands for Office of the Technical Regulator
Public Land – has the meaning given to that term in the Electricity Act 1996, namely land
owned by the Crown or an instrumentality or agent of the Crown or by a council or other local
government body, including any such land that is subject to native title
Property – For the purpose of these Rules „property‟ means either what is commonly described,
as a Torrens Title allotment, a Community Title Scheme or Land, which is owned by the
Crown on which the owner/occupier has the right to the installation of an electricity supply A
property may include any combination of contiguous (adjacent) land and/or an individual title
that constitutes a single development, to which an owner/occupier or a Customer has the right
to the installation of an electricity supply
Shall – is to be understood as mandatory requirement or obligation
Should – is to be understood as non-mandatory, i.e advisory or recommended
Suitable (or suitably) – means to the satisfaction of the relevant SA Power Networks Manager Separation Distance – It is either the vertical and/or the horizontal distance, measured between
any SA Power Networks plant and the Third Party‟s infrastructure
Underground Service – The electricity distributors supply network to the point of supply
Water Course – Refer to TS-100
Works –
Planned: the works, which has followed the normal planning process, prior to work
commencing, i.e where, the worksite has been physically inspected and assessed, in
advance of the work crew, arriving on site
Unplanned: any urgent works were there has not been a reasonable opportunity to follow
normal planning processes prior to work commencing This includes works where the
supervisor has not physically inspected the work place or where a work crew has come
across a scope of work requiring action during the normal course of their duties
Emergency: where a crew is despatched to the work site, in response to an immediate
threat/danger to an individual, the public, or the asset
WSAA – Water Services Association of Australia
Trang 126.0 BACKGROUND
The responsibility for the installation of a trench for the installation of SA Power Networks
infrastructure can be:
The Customer for a network extensions which includes land developments, Network
Extensions or Customer alterations to the SA Power Networks electrical network;
Council for Power Line Environment Committee (PLEC) projects; and
SA Power Networks for capital works, and under specific arrangements, some customer
works
The Electricity (General) Regulations 1997 (Part 6, Section 39A), requires a separation
between a building or a structure and underground powerlines:
At a voltage of 33kV or less shall be within 2.0 m; and
At a voltage greater than of 33kV shall be within 3.0 m
Any trench installation not meeting these requirements will be non-compliant without
exemption from the OTR The Designer/Contractor will need to supply OTR exemption as a
component of Civil Works “Compliance Form” There are other separation requirements
documented in section 9.6 in this document that are requirements of other service providers
A trench containing SA Power Networks cables and the associated conduits are to be
positioned in the straightest possible alignment to accommodate future cable installations SA
Power Networks may agree to provide a quotation for the installation of a trench on behalf of a customer For access to the list of Civil Contractors utilised by SA Power Networks refer to
NICC-203 which is available on our Internet website Undertaking of trenching shall be in a
workman-like manner and shall meet the requirements of TS-085 and any other relevant
specification
The trench containing the electrical works is a component of the asset inspection process and it
is the responsibility of the customer/land owner to ensure that the trench meets the
specification An SA Power Networks Asset Compliance Officer may inspect the trench at any time
A non-compliance notice will be issued for any civil works, where remedial work to a trench is required to meet this Technical Standard including any other associated specifications
requirements If there is any query relating to the requirements of this Technical Standard
(TS-085), please contact the Network Project Officer (NPO) responsible for the project
The Customer or an Agent of the Customer shall be responsible for the following:
Ensuring that all allotment pegs, including any replacement pegs, easement pegs and level pegs are correctly placed, clearly visible, and numbered to show allotment numbers, reserves, easements etc;
Carrying out and co-ordinating all the pegging, trenching, backfilling, reinstatement,
levelling, and associated work including retaining walls, necessary for the installation of cables, padmount transformers and switching cubicles, service pits, pillars and lighting columns
All street, ground openings, all costs associated with the compaction/reinstatement of
road/footpath surfaces and services where disturbed or damaged, are to be the satisfaction
of the authority or owner concerned;
Trang 13 The safety of the open trench and any liability arising from the Customer‟s works, this
includes ensuring that there is suitable clearance between any excavation and existing SA Power Networks infrastructure, including poles and footings A financial penalty can be applied by the industry Regulator for any unlawful interference;
Ensure that the necessary arrangements are made with the local authorities and public
service utilities for the temporary disturbance of any driveway, culvert, pipe, drain, kerb, survey mark etc;
Excavations of padmount transformer vaults/footings and/or switching cubicle
vaults/footings and the reinstatement of the remaining excavation surrounding these vaults; and
Damage caused to vaults and associated equipment during backfilling and compaction
The area around the padmount transformer and a switching cubicle and in particularly the
front of the equipment/operating area requires 24hrs/7days access This area from the time
of the cable installation needs to have a finished base in place or as a minimum; the ground drained and crushed rock compacted in place
As per the manufacturers and SA Power Networks‟ specifications, this is an essential
requirement to ensure that the cable installation, termination and testing phase can be undertaken in a clean and dirt free environment
The testing phase will not be undertaken until the site conditions for the operating area are satisfied
8.1 Access Permit Requirements
A Contractor shall not work near any live SA Power Networks electrical cables All electrical
cables shall be treated as being live (energised) Contact Dial before You Dig on telephone
number 1100 to verify the location of SA Power Networks and other infrastructure prior to the commencement of any Civil works The trench is a critical and integral part of the electrical
installation
Any Contractor intending to perform any works within the vicinity of any electrical
infrastructure shall follow the directions outlined in SA Power Networks‟ NICC-404:
“Information on Contractor Access & Working in the Vicinity of the Electrical Network”
An access permit may be required if any electrical cables are in close proximity to the intended work site A Contractor can contact the Network Access Officer (SA Power networks‟ NOC
Centre on 08 8404 4119) for further information SA Power networks cables can be easily
damaged and costly to repair
8.2 Safe Edge Shovel Requirements
SA Power Networks cables are covered in a soft layer of polyethylene, which is very easily
damaged To reduce the severity of damage to the outer sheath, all Contractors who have to
work in the are of the electrical infrastructure shall utilise a safe edge (blunt nosed) shovel
A fibreglass handle shovel with a safe edge is available for purchase from SA Power Networks Logistics Please contact Marleston South Sales Team on (08) 8292 0489 and request for the
Trang 14A Contractor is able to utilise a shovel of their choice but it must have a safe edge A
modification service to install a „safe edge‟ on a Contractor‟s shovel/s is available from
ADMECH Pty Ltd, (admech@internode.on.net Mobile: 0409 097 380, (08) 272 0151), who
have the specification for SA Power Networks‟ requirements
A safe edge shovel minimises cable damage if a Contractor inadvertently encounters a cable
Any damage to SA Power Networks infrastructure will be at the cost of the responsible party
If any party is aware of any damage to the electrical infrastructure, please notify SA Power
networks at the earliest opportunity Early notice may reduce future repair costs
8.3 Civil Works Notification Requirements
Civil works forms are a component of the asset inspection and vesting process Refer to
Appendix – A of this document for more detail The NICC-453: Civil Works Notification
Form” shall be submitted to the appropriate SA Power Networks representative
The following notice period is required:
A section (contestable projects) 10 working days notice
8.4 Civil Works Compliance Requirements
SA Power Networks regulatory requirements include an undertaking that any electrical
installation is compliant with the relevant codes and standards
Civil works and conduit installation forms a part of the SA Power Networks electrical asset and must be to a standard that satisfies all of the relevant external and SA Power Networks‟
standards and specifications
To assist in the verification that the Civil works are to standard, a “NICC-452: Civil Work
Compliance Form” is required from the Civil Contractor as a part of the electrical compliance Refer to Appendix – A of this document for more detail
Note: The “NICC-452: Civil Work Compliance Form” shall be completed for all projects with
a trenching component, as it is a prerequisite to acceptance of the “Certificate of SA Power
Networks Electrical Compliance”
8.5 Civil Works Non-Compliance
The Civil Contractor shall complete “NICC-452 Form” and ensure this form is forwarded to
the Electrical Contractor or to the nominated SA Power Networks Officer This form is an
integral component of the “Certificate of SA Power Networks Electrical Compliance”
If the Civil Contractor delays and/or does not submit a completed NICC-452 form, until the
time of the final asset audit/sign-off stage, then this may result in delays to a customer‟s
connection
A non-compliance notice and the relevant charge will be issued to the responsible Contractor
for any Civil works installation that does not meet the SA Power Networks specification
Any fees due to SA Power networks that are associated with any non-compliance shall be paid
in full, prior to the final electrical connection Any non-compliance related to Civil works must
be rectified prior to SA Power Networks accepting the “NICC-452: Civil Works Compliance
Trang 158.6 Requirements of Changes to Civil Works
It is Civil Contractors‟ responsibility to ensure that any details regarding changes to the
installation be forwarded to the electrical designer This will ensure that there is an accurate
and permanent record
8.7 Directional Bore Drawing Requirements
The Contractor undertaking the boring works shall supply a log for the total length of the bore
for inclusion on the „As Constructed‟ design Refer to TS-100 for the directional bore drawing preparation detail Also, refer to Appendix – C for “Example of Directional Bore Drawing” of
this document
Further clarification can be obtained from the Facilities Records Coordinator through the SA
Power networks Project Manager
8.8 Backfilling and Consolidation
The Contractor shall carry out the backfilling of trenches, tunnels, joint bays and any other associated excavations as soon as practicable after cable/conduit laying and/or jointing is completed If any installed cable cannot be backfilled at the end of the working day, a Contractor shall consider security provisions to ensure the cable is not vandalised
Before commencing the backfilling operations of any trench excavation, surplus-jointing
materials, any wast materials, all rubbish including timber, foreign material, free water and slurry shall be removed from the trench
Backfill material shall not be placed in any excavation containing free water or slurry The excavation shall be clean and completely free from all fibrous and vegetable matter and other material, which may attract termites Excavated material from the trench may be permitted as backfill (above the bedding sand), if this material is predominantly a soil
Excavated material that contains any metal and/or rocks may be permitted, if it satisfies the following criteria:
1 The amount of metal and rocks is less than 20% of the material (by volume)
2 The metal and rocks pass through a 50mm screen
3 Approval for any back fill arrangement with excavated material is by agreement with the SA Power Networks Project Manager on a Case-By-Case project basis
Where cables and/or conduits are laid beneath other buried services, the Contractor shall
ensure that the backfill beneath such services is adequately compacted such that no voids between cables and/or conduit layers detrimental to the cable rating occurs; and damage to the other buried services, due to inadequate support is prevented
Consolidation of the backfilled excavations will be in accordance with the local Council or Department of Transport, Energy and Infrastructure specifications as appropriate If there
is no third party specification on compaction the nominal SA Power Networks specification is 95% unless otherwise specified
Trang 169.0 RETAINING WALLS
9.1 General
A padmount transformer can weigh from 2.45 tonnes to 6.45 tonnes and capacity range from
315 kVA to 2.0MVA respectively There may be a requirements to establish a retaining wall to ensure the padmount transformer has a stable footing and remains in a horizontal orientation
Refer to Technical Standard (TS-102) for the easements details
Specifying the need for a retaining wall at the design stage provides the following benefits:
Informs the Customer/Civil Contractor for the need of a retaining wall;
Escalates the need for a specific engineering approved retaining wall design on extremely
sloping sites; and
Ensures the easement for the electrical design drawing and the subsequent transfer to a
deposited plan is appropriate in size to fit the padmount transformer and the retaining wall
9.2 Design Consideration for the Retaining Walls
A retaining wall for a padmount transformer and/or a switching cubicle in any location will be required where there is a change in the ground level to accommodate the padmount transformer and/or switching cubicle in a suitable horizontal orientation
The design requirements for the retaining walls should consider the following:
The location of the padmount transformer(s) and/or switching cubicle(s), and the slope of
the natural ground level;
Construct a retaining wall that satisfies any SA Power Networks and electrical equipment
manufacturer‟s requirements;
Any retaining wall above 1.0m in height will require:
1 The involvement of a certified structural/Civil engineer to verify the adequacy of any retaining wall installation;
2 Provision of engineering calculations/confirmation that the design can be requested for any style construction; and
3 Where construction to the manufacturer‟s specification cannot be verified and where the retaining wall is over 1.0m in height then council approval is required
The retaining wall and any other SA Power Networks plant (e.g cables) shall be within
any SA Power Networks registered easement where an easement is required;
The retaining wall should ideally be positioned at the extremity of the SA Power Networks easement and should not encroach into the area occupied by the padmount transformer and/or a switching cubicle;
When required, construction of a retaining wall shall be entirely within the easement
(Refer to figure-1 below);
Where the retaining wall is placed beyond the standard easement, the easement shall be
extended to include the area occupied by the retaining wall;
For any filled retaining wall, there shall be a buffer zone The buffer zone shall be the
minimum width that is equal to the height of the retaining wall The maximum width required is 1.0m Extend the easement boundary by 1.0m to allow the filled retaining wall constructed 1.0m inside the easement boundary (Refer to figure-2 below).;
Trang 17 Any cut or fill greater than 300mm in the area up to 2.0m from the easement boundary will require a retaining wall;
Any fill above the natural ground profile (that in effect creates a raised island) on any site
will not obviate the need for a retaining wall;
Dispensation may be given to a retaining wall if the surrounding ground level change is of
a minor nature only and all of the land between the easement boundary and the 2.0m point
is within a reserve; and
The installation of a retaining wall shall be completed prior to the installation of a
padmount transformer and/or a switching cubicle;
If above stated requirements are not met, then non-compliance will be issued
Refer to the TS-102: Easement Standard, Appendix-B for fill and cut scenarios of retaining wall details;
A retaining wall construction needs to be of a quality that will ensure the long-term
stability and safety of the SA Power Networks‟ assets;
The retaining wall and backfill shall be designed to drain the area behind the wall and
continue to do so indefinitely without blockage, so that hydrostatic pressure is not exerted
on the wall at any time;
A more effective system of drainage consists of a continuous agricultural pipe located at
the base of all retaining walls and be surrounded by gravel or crushed stone with a continuous vertical layer of granule material at least 300mm thick covering the rear face of the wall area;
Retaining walls shall be constructed of concrete masonry materials;
For vertical block type retaining walls, a suitable concrete/steel reinforced foundation shall
be constructed;
If interlocking style blocks are utilised, they shall be of a pinned or socket and nib type
The two top courses shall be pinned and glued with an epoxy style resin and the top course shall consists of a glued top capping;
Any brick style retaining wall construction will not be approved unless the number of
courses is a minimum 5;
Open style interlocking blocks may be acceptable provided the soil is retained The use of
Geo cloth type material may also be acceptable Ensure that the material to be utilised for a retaining wall will be acceptable to SA Power Networks;
This style of retaining wall construction has the potential to require an easement larger than standard in order to provide the required retaining wall strength Please contact your SA Power Networks Network Project Officer prior to installation
SA Power Networks reserves the right to request engineering calculations for any retaining wall SA Power Networks will consider a submission from a Certified Structural/Civil Engineer to a variation to the construction material utilised for a retaining wall as described
Trang 18 Material to be retained shall be classified in one of the 3 types listed below:
1 Coarse-grained soil without admixture of fine soil particles; Very permeable (clean sand or gravel);
2 Coarse-grained soil of low permeability due to admixture of particles of silt size;
and
3 Residual soil with stones, fine silty sand and granular materials with conspicuous clay content
Materials not acceptable include very soft or soft clay, organic silt or silty clays, and
medium or stiff clay;
Weep holes shall be provided in the retaining wall at the lowest points;
An open drain shall be provided to remove water from the area of the toe of the wall;
Dispensation for the installation of a retaining wall can be granted by the relevant regional Network Manager when the following can be verified:
1 The short and long-term stability of a padmount transformer will not be compromised
2 The easement site and adjacent properties will not be impacted by erosion run off;
i.e It can be demonstrated that the site adjacent to the easement is well consolidated and/or there is other means of retainment or removal of any run off material
9.2.1 Other Design Requirements
consider the following:
A site meeting prior to the installation of the common service trench is an appropriate time to discuss retaining wall installation requirements
Note: If there are any issues, the relevant party should address them and if
required, confirmation received from the Designer/Project Officer that the proposed installation will satisfy the specification
The electrical Contractor needs to be very specific at any site meeting that a padmount transformer and/or switching cubicle will not be installed until the completion of the retaining wall;
Non-compliance will be issued if a retaining wall is not installed as required As a reminder, padmount transformers and switching cubicles are heavy and the risk of installing a retaining wall on a filled site around installed equipment is very risky, particularly in periods of wet weather
The Compliance group will generally not visit a site for the purposes of issuing a Certificate of Compliance until any required retaining wall(s) are installed and completed
A non-compliance will be issued by SA Power Networks if any of the following conditions are not met:
1 Engineering confirmation is not available when required
2 The construction is deemed inferior in quality
3 On site inspection, SA Power Networks identifies that retaining wall were required but have not been constructed
4 For vertical block type retaining walls, a suitable concrete/steel foundation is missing
Trang 195 The retaining wall(s) provided do not meet any of SA Power Networks‟ specified requirements
Operating Area Refer to TS-102
TRANSFORMER
Boundary of Public Area if appropriate
Easement to be extended to include the area occupied by the retaining wall if required
Area for SA Power Networks
Equipment (on standard easement) Refer to TS-102
Retaining Wall
OR SWITCHING CUBICLE
FIGURE 1 - RETAINING WALL
Weep hole
Ground level Retaining Wall
SA Power Networks Transformer/
Note Retaining wall to be built up
to the height of the base
Suitable Retaining Fill
Ground Level
* 1.0m * SA Power Networks extended easement
requirement for a “Fill” situation
FIGURE 2 - RETAINING WALL – FILL
Trang 20FIGURE 3 - RETAINING WALL – CUT
10.0 TRENCHING
10.1 General
When installing conduits/cables in a trench, consider the following Design Requirements:
The trench shall be as straight as possible with a firm and smooth base;
The installation of multiple conduits requires a minimum separation of 25mm in all
directions (or as otherwise specified) between SA Power Networks conduits This is to ensure the bedding sand fully encompasses the conduit at the time of back filling This will reduce future compaction issues (Refer to figure 4 below);
There shall be a minimum separation of 50mm in all directions (or as otherwise specified)
between direct laid SA Power Networks cable circuits The greater the cable circuit separation, the greater the current carrying capacity of the electrical cable (Refer to figure 4 below);
Note:
If the trench width allows for greater than 50mm separation, the preferred installation method
is to increase cable separation to maximise the spacing From time to time, there may be a
requirement for a specific separation that is greater than the minimum (Refer to figure 4
Under some circumstances, SA Power Networks may approve a lesser dimension if it can
be verified the trench edge is such that it will not damage the installed cables or if the installed conduit is medium or heavy duty (Refer to figure 4 below);
Trang 21FIGURE 4 – TRENCHING
Dimensions for SA Power networks infrastructure in this standard are the minimum except where shown;
The maximum depth of any length of open trench should not be greater than 1.2m without
SA Power Networks approval;
Any trench, which has depth/cover over 1.5m, requires additional construction
requirements For trenching and shoring examples, refer to the OHS&W Regulations 1995
Locate the trench, where practicable, in accordance with the publication “A Code for the
Placement of Infrastructure Services in New and Existing Streets” (Services in Streets
Code)
Note:
This code is prepared by the Public Utilities Advisory Committee (PUACC) and available from the Local Government Association
The installer shall submit all variations to the construction drawing for inclusion on the
“As Constructed” SA Power Networks drawing;
It is the Civil and Electrical Contractors responsibility to forward hand written mark-ups of hard copy drawings detailing all changes and necessary installations information are returned to the designer within 30 days of completion to ensure that the final “As Constructed” drawings are correct
For the specific requirements relating to the submission of “As Constructed” drawings,
refer to TS-100 – clauses 6.3 and 6.5 which is applicable to all Civil installations
10.2 Trench Requirements for Road Reserve/Crossing
The following requirements apply for road reserves and road crossings:
Open trench road crossings in existing streets where there is to be a reinstatement are to be
at 90 degrees to the kerb Any variation to this will require council approval;
The minimum cover under a carriageway shall be 750mm A road controlled by the
Department of Planning, Transport and Infrastructure (DPTI) have specific requirements which are detailed in clause 10.3;
All cables under carriageways shall be installed within a suitably sized and class of
conduit Any variation to this shall be at the approval of SA Power networks Spare conduit installation under a carriageway is to be as per clause 10.5 of this standard;
Cables 25mm
50mm
Cable circuit separation 50mm minimum (Refer section 9.1 & 9.2) 25mm
Bottom of trench
Conduit
50mm Bedding Sand
Trang 22 For a primary cable network that is buried direct in the primary trench in a road reserve
such as a single customer network extension or a common service trench for a development there is a requirement for spare conduits (Refer clause 11.2 below);
Spare conduits installed at a road crossing shall match the spare conduits in the primary
trench The road crossing conduits shall be continuous with the primary trench spare conduits where practical
These conduits will be in addition to the conduits at a road crossing which shall be utilised for a direct buried cable installation
Spare conduits installed at a road crossing that are for a direct buried cable installation
shall extend the full width of the carriageway and extend 900mm into the footpath verge from the back of the kerb;
The electrical designer and Contractor responsible for conduit installation at road crossings shall ensure that the appropriate numbers of conduits are installed;
The conduit for a radial low voltage installation needs to be continuous (fully conduited)
with LD conduit between pillars and installed in such a way that it will facilitate quick cable replacement If this is achieved a spare conduit is not required; and
Any road crossing excavation for continuous conduits needs to consider the cover and
trench floor invert of the conduits that are to be installed in the road verge
For trenching design, requirements refer to TS-100 and refer to figure 5 below for the “Typical Road Crossing Trench Alignment”
FIGURE 5 - TYPICAL ROAD CROSSING TRENCH ALIGNMENT
Trang 2310.3 DPTI Requirements for DPTI Controlled Roads
The Department of Planning, Transport and Infrastructure (DPTI) have very specific
requirements for any work undertaken on a DPTI controlled road For more details, refer to
link Works on Roads by Other Organisations on the DPTI website
It is SA Power Networks expectation that a Civil Contractor is conversant with the DPTI
standard specifications, if working on a DPTI road
The information DPTI requires may include:
Barriers, Warning Signs and Lighting Installations;
Traffic Management;
Native Vegetation Management; and
Roadside Significant Sites of an Environmental or Cultural Significance
DPTI requirements can impact both a designer and a constructor In country regions, DPTI
have highlighted most DPTI controlled roadside sites with a distinctive but discreet marker
Information on Transport SA Guide to Matters of National Environmental Significance and a
List of Roadside Significant Sites visit Transport SA website
10.3.1 DPTI Open Shared Trenching Requirements
Most trenching involves work on medium or heavily trafficked roads with an asphalt surface There is a requirement that all services shall be at a minimum depth of 1.0m cover
Any trenching involving an SA Power Networks installation and other authorities may require a wider trench to ensure that appropriate separations are achieved without shoring requirements Reinstatement needs to be as per DPTI‟s standard specification and avoid reusing excavated material
For various trenching arrangements visit DPTI website on Reinstatement Pavement Configuration
10.3.2 DPTI Trenchless Boring Requirements
Multiple conduits can be passed through a single bore or tunnel It is required that there be a minimum spacing of 10D between single bores where there are multiple bores where D is the diameter of the largest conduit Refer to figure 6 below
The minimum depth of a trenchless bore will generally be 1.5m to minimise ground swell The final depth is to be determined in conjunction with the boring Contractor, with the minimum depth to be achieved wherever possible Refer to figure 6 below
Trang 24FIGURE 6 SPECIFIC DPTI REQUIREMENTS FOR TRENCHLESS BORING
10.3.3 DPTI Notification
The electrical designer shall submit any design to DPTI for comment where any SA Power Networks infrastructure, i.e., poles, cable or conduit, will be running parallel to the kerb for some distance
This is to ensure any installation takes into account any future road widening
The notice is required for the following:
Any work that requires traffic management, this may also include work on overhead mains;
An open trench or trenchless boring; and
Any cable pulling through installed conduits
10.3.4 DPTI Traffic Control Notification Process
The Metropolitan Traffic Control Centre – telephone 1800 018 313, shall be notified
of any SA Power Networks and Civil works that required DPTI approval (to clause 10.3.3 above)
The Metropolitan Traffic Control Centre requires notification 15 minutes prior to work commencing and 15 minutes after the road has reopened Download Notification Form from the DPTI website
10.3.5 DPTI Emergency Work Requirements
DPTI requires verbal notification to the appropriate DPTI representative at the earliest opportunity This shall be forwarded by submission of a Notification Form within 24 hours of the emergency
Ground Level Min.1.5m
10 X 125mm = 1.25m minim 100mm conduit
Trang 2510.3.6 DPTI Maintenance Period Requirements
The Contractor undertaking the Civil component of the electrical works associated with a DPTI road crossing will be responsible for the cost of making good any settlement or other deterioration in the reinstated excavation for the maintenance period, which is one year
10.4 Public Road (Non DPTI Roads) Controlled by Council
For a public road that is not under the control of DPTI the authorisation to excavate and back
filling requirement will normally need to be sourced from the relevant Council
SA Power Networks will require a copy of the approval from the relevant Council plus details
of Civil Works This information is a component of the SA Power networks Civil Works
Compliance process
10.5 Conduits within Railway Boundaries
Refer to AS 4799 – Installation of Underground Utility Services and Pipelines within Railway
Boundaries, which specifies the requirements in detail for both the design and installation of
electrical infrastructure within a railway property
There are specific design information requirements and approvals needed to gain right of entry
as well as easement agreements within railway boundaries/corridors The Underground Service
Request - Trains and Trams online electronic form is available from the Transadelaide website
This online form shall be completed and submitted by the designer a minimum of 14 working
days prior to any work taking place
A copy of the approval shall be forwarded to SA Power Networks relevant Project Manager
and to the: SA Power Networks Easements Coordinator, Level 6, 1 Anzac Highway,
KESWICK SA 5035, Telephone: (08) 8404 5897, Fax: (08) 8404 5193 There are a number of other authorities that SA power Networks may require approval from, such as:
Australian Rail and Track Corporation;
Australian Southern Railroad; and
Department of Planning, Transport and Infrastructure (DPTI)
When installing conduits/cables within railway boundaries also consider the following
requirements:
With the submission, a preliminary design drawing or a section of DCDB with street
names, rail lines and the crossing point marked;
Confirmation that any conduits that are to be installed, satisfies the design load for the
railway loading may be required;
Confirmation from the railway authority that the electrical design has approval will be
required prior to SA power networks issuing a Specification Compliance;
An electrical conduit should be installed a minimum of 2.0m deep under any rail line for a 3.0m distance beyond the outer rails Refer to figure 7 below;
Conduits in other locations within railway property shall have 1.0m minimum cover; and
A railway authority may approve a lesser depth, but the depth shall not be less that the SA
Trang 26For more details refer to Guidelines for SA Power Networks Crossings of the Electrified DPTI Railway Network
FIGURE 7 - CABLE DEPTH REQUIREMENTS UNDER RAILWAY CROSSINGS
10.5.1 Telecommunications Pilot Cable Only
Where there is a single pilot cable underground rail crossing and where Civil-works has to be completed with an under-bore, the use of a single Ø63mm O.D bore pipe may be acceptable; however, this shall have written approval from the SA Power Networks Network Telecommunication Manager
10.5.2 Telecommunications Fibre Optic Only
Where there is a single fibre optic underground rail crossing and where Civil works has to be completed with an under-bore, the use of a single Ø63mm O.D bore pipe shall be installed
Notes:
1 Pits shall be P8 size (stock item RA5461)
2 Outer bore pipe is to enter pit body using a bell-mouth spigot Ø63mm
3 Pole side of pit is to have bell-mouth installed in preparation for SA Power Networks installers to extend conduit to pole
4 Install pits so that the closest edge is nominally 2.0m from edge of pole
10.6 Clearances between Services
For normal trenching and trenchless technology installation, clearance from SA Power
Networks assets to other service utility assets shall not be less than (and preferably exceed) the minimum vertical and horizontal clearances as shown in Table 1 (Vertical Separation) and
Table 2 (Horizontal Separation) below
Written agreement on reduced clearances shall be obtained from the relevant SA Power
Networks Manager and the relevant Service Owner Refer to Appendix F below and for
clearance in shared trench arrangements, refer to Appendix D, E, G, H and K below
The following notes apply to Table 1 and Table 2 below:
1 For any other authorities‟ infrastructure, crossing SA Power Networks cables (and
associated conduits), which are less than 66kV, a minimum separation if not specified as greater by other authority is 150mm
SA Power Networks access point(s) to be located outside of the rail corridor and the depth of the cables outside
of rail corridor to be the requirements of TS-085 and TS-100
SA Power Networks cable
in conduit
Rail Corridor Boundary fence
3m minimum
to AS 4799
Depth to the requirements of
Trang 272 For any other authorities‟ infrastructure, running parallel to SA Power Networks cables
(and associated conduits), which are less than 66kV, a minimum separation if not specified as greater by another authority is 600mm
3 For any other authorities‟ infrastructure, crossing SA Power Networks 66kV cables (and
associated conduits), refer to Section 17.4
4 For any other authorities‟ infrastructure, running parallel SA Power Networks 66kV
cables (and associated conduits), refer to Section 17.4
5 Any authority that is unable to achieve these specified minimum separations needs to
contact SA Power Networks for approval
6 As per AS/NZS 3500.3, the minimum separation between any underground stormwater
drain and an electrical supply cable shall be at least –
a 100mm provided the electrical supply cable is indicated along its length with orange marker tape complying with AS/NZS 2648.1 and is mechanically protected;
or
b 600mm, where the electrical supply cable neither indicated nor mechanically protected
7 Refer to AS 2885.1 for clearances to the high-pressure gas mains
8 As per AS/NZS 3500.3, the minimum separation between any underground stormwater
drain crossing another service shall –
a Cross at angle 90° if practicable, but not less than 45°;
b Have a vertical separation of not less than 100mm; and
c Be marked along its length for 1m either side of the centreline of the service with marker tape complying with AS/NZS 2468.1, laid 150mm above the installer service
9 Refer to AS/NZS 4645.3, which states that:
a Where a plastic main or service is laid parallel to other utility assets, a minimum separation distance is required in order to affect repairs The minimum separation distance shall be 250mm; and
b Where a plastic main or service is crossed by other services, the minimum separation distance shall be 100mm Additional separation may be required for large utility assets in order to affect repairs
10 All clearances are in millimetres and are minimum separations
11 To achieve minimum clearances in Table 1 and Table 2, it may be necessary to increase
the cover on SA power Networks cables and/or conduit or increase the trench width; this will require SA Power Networks‟ approval
12 Where an SA Power Networks LV service pillar is inside a property boundary, the
clearance SA Water requires to any water service from the LV service pillar shall be 1.0m
13 For clearances to stobie poles and public lighting columns please consult the SA Power
Networks Project manager
10.6.1 Vertical Separation between Services
These minimum dimensions are relevant where external parties‟ infrastructure is vertically parallel, cross over or under SA Power Networks equipment
Refer to notes and Table 1 (below) for the minimum vertical separation between services
Trang 2810.6.2 Horizontal Separation between Services
Horizontal separation will be dependent on the extent that the external plant is parallel with the SA Power Networks infrastructure To ensure compliance with the NICC-404 only hand digging is permissible for any excavation within 1.0m of any SA Power Networks assets
Refer to notes and Table 2 (below) for the minimum horizontal separation between services
TABLE 1 - VERTICAL SEPARATION BETWEEN SERVICES
LV Mains
SA Power Networks
HV < 66kV Mains
SA Power Networks 66kV Cables
Non-SA Power Networks
Approval Required from
SA Power Networks‟ MNP
(Refer to Notes 3 &
4, in clause 10.6 and Section 17.4)
Non-SA Power Networks
(for other sewer mains)
Private Sewer (Refer to note 1, in clause 10.6)600 (Refer to note 1, in clause 10.6)600
Trang 29TABLE 2 - HORIZONTAL SEPARATION BETWEEN SERVICES
LV Mains
SA Power Networks
HV < 66kV Mains
SA Power Networks 66kV Cables
Non-SA Power Networks
Approval Required from
SA Power Networks‟ MNP
(Refer to Notes 3 &
4, in clause 10.6 and Section 17.4)
Non-SA Power Networks
(for other sewer mains)
Private Sewer (Refer to note 1, in clause 10.6 )600 (Refer to note 1, in clause 10.6)600
(Refer to note 8, in clause 10.6)
10.7 Changes in Levels and Directional Changes
The depth of any conduit installation in the carriageway should match that of any conduit
installation on the road verge (footpath) If this is not achievable, the cover at the end of a
conduit at a road crossing should be at the same level as the conduit in the verge
To achieve this, install conduit bends, if needed A straight length of the standard 100mm Light Duty/Class 6 conduit has the possibility of a minor degree of bending (i.e approximately 10 to
15 degrees over the length of the conduit) Any deviation greater than 15 degrees will require
the installation of appropriate bends
Do not install under any circumstances, any conduit with a kink in its length The repair of any damaged conduit section will be required prior to SA Power Networks accepting the asset Any major variation to the depth of a conduit will have an impact on the ease the electrical installer will have installing a cable in a conduit
A gradient rise or fall should be limited to 100mm per metre for the primary run of SA Power
Networks cables and conduits Appropriate bends with the smallest radius requirement to
achieve a satisfactory clearance to other services should be utilised
Retrospective undergrounding projects will provide challenges to the Civil Contractor from
time to time when other service providers‟ infrastructure is encountered within the trench It
will be the Civil Contractors‟ responsibility to resolve these issues and the assistance of the SA Power Networks NPO should be sought to ensure that the solution proposed is to the
satisfaction of SA Power Networks prior to construction
Trang 30Refer to figure 8 below for examples of conflict and possible solutions Also, refer to Table 2
for the minimum horizontal separation between services The example in figure 8 shows an
in-appropriate conduit coupling with excess tension applied to both the coupling and a straight
length of conduit
It is important that the Customer and electrical Contractor establish appropriate ground levels
at the time of the installation of the electrical works to ensure that there is no requirements to
alter ground levels by a third party after installation Under the Electricity Act 1996 and
Electricity (Gen.) Regs 1997, the SA Independent Regulator can impose a fine for any breach
Refer to Part 6, Clause 38 of the Electricity (Gen.) Regs 1997
FIGURE 8 - CHANGES IN LEVELS AND DIRECTIONAL CHANGES
10.8 Shared Trench Arrangement
A shared trench arrangements is normally installed as a part of a Greenfield housing project
The shared trench is the responsibility of the Customer and contains electrical and other
infrastructure providers‟ assets
Refer to clause 10.1 for “Cable/Conduit Requirements for the SA Power Networks Trench”
and for more details relating to the installation of 66kV cables, refer to clause 17.0 “66kV
Underground Cable Installation” within this document
When installing conduits/cables in a shared trench, consider the following:
The trench width can vary from 450mm wide up to 1.2m wide; however, the trench width
is dependent on the cable/conduit specification and configuration, footpath/road location and soil type;
The design drawings shall specify all trench widths and be submitted to SA Power
Networks for approval prior to installation;
The trench depth will normally be a maximum of 1.2m;
Subject to the SA Power Networks approval, a trench depth could be up to 1.5m deep or
even deeper for the 66kV projects, depending on site specification, conduit arrangement, soil type, and footpath/road location The design drawings shall specify all cable depths;
The depth of the trench shall be such as to achieve a minimum cover of 750mm above
conduits and cover of 1.0m above all direct buried cables to the ultimate finished ground level;
Preferred gradient rise/fall
of conduit 100mm per 1metre For primary run.
SAPN conduit
Note
If Y > 1.5m it may be preferreble to go over service.
150mm minimum under service.
any tension This
creates a lip which
can damage cables
`Y‟
G.L.
Alternative Conduit route
Trang 31 For Non-DPTI roads, a 750mm minimum cover from the finished road service level at the
kerb invert shall be maintained; Refer to “Services in Streets Code” for trench location in a
road reserve; and
Maintained vertical and horizontal separation (clearances) between services as stated in
clause 10.6 of this document
10.8.1 Typical Shared Trench Cross Sections
For various typical cross sections of shared trench occupied by the SA Power Networks underground HV cables up to 11kV and LV cables and Telecommunication, Thirty party Telecom, Private/Consumers service mains, CLER, Public Light and Gas, refer to the Appendices D to K in this document for detailed sketches
The following notes apply to Appendices D to K of this document:
1 Install SA Power Networks Telecommunications conduit outside the line of any pits Conduit shown is Ø100 ID (drawn to Ø110 OD), Class 6, White, LD (use Sub Ducts if required)
2 Install spare LV conduits thru to SA Power Networks Pit (preferred location is on property side) Conduit shown is Ø100 ID (drawn to Ø110 OD), Class 6, Orange,
LD, and stock item no NC2505
3 Install spare HV conduits outside the line of any pits (Preferred location is on kerb side of service pit) Conduit shown is Ø100 ID (drawn to Ø110 OD), Class 6, Orange, LD, and stock item no NC2505
4 Public light, Private Consumer and CLER conduits are shown as Ø32 O.D, Orange, HD, stock item no EA8405
5 Gas mains, shown as Ø100 ID (drawn to Ø110 OD), cover 750mm with 250mm min clearance shown dotted lines to other services
6 Flexible consumer gas pipe is shown as Ø20 O.D with 100mm min clearance to other services
7 Third party Telco, shown as Ø100 ID (drawn to Ø110 OD) with 100mm min
clearance showed dotted lines for LV and 300mm min for HV
8 HV and LV in Conduits are shown as Ø100 ID (drawn to Ø110 OD), Class 6, Orange, LD, and stock item no NC2505
9 On the property side shown dotted lines are for the SA Power Networks P7 pit and third party Telco P8 pit The preferred installations of these pits are fully within the trench or half way centre line of pits to the trench edge
10 All dimensions are in “mm” unless otherwise specified
11 For any installation of 33kV HV cables, refer to Electricity (Gen.) Regs 1997, Schedule-3, Section-7 and Table-1
10.8.2 Trenching for SA Power Networks Telecom Only
Refer to Appendix-G for the trench arrangement when conduits are required for SA Power Networks Telecommunications only For SA Power Networks
Telecommunications conduits that will only have Optic Fibre Cables installed, then a marker tape with tracer wires shall be required
Trang 3210.8.3 Typical SA Power Networks only Trench
For typical cross sections of a trench occupied ONLY by the underground SA Power Networks HV/LV mains & Telecommunication cables, Refer to the Appendix - E
This situation only covers scenarios where SA Power Networks do not share a trench with other parties such as Third party Telecom; Private/Consumers service mains, CLER, Public Light and/or Gas For minimum depth of cable cover requirements refer
to Electricity (General) Regulations 1997 – Schedule 3 – Section 7 – Table 1
For maintaining safety, reliability and protecting SA Power Networks undergrounding
HV and LV asset, SA Power Networks specific requirement is to maintain 750mm minimum cover for HV and LV infrastructure, conduits or cables in conduit measured from the ground surface to the top of conduits and 1.0m minimum to the top of direct buried cables
If these minimum requirements are unachievable then consult the relevant SA Power Networks Manager
10.8.4 URD Trench Design Requirements
For URD trench design requirements refer to TS-100
10.8.5 Trenching for Retrospective (PLEC Schemes)
Trench dimensions shall be sufficient to satisfy the minimum dimensions and clearances that are specified in this Technical Standard (TS-085) and/or as specified in the SA Power Networks specification
The designer will also need to consider for each installation the available space; proximity to other services; DPTI design and operational
requirements;
The preferred method of trenching in an existing road reserve, which is located in a busy footpath and vehicular traffic area, is to install a full conduit system at the appropriate depth and back fill on completion of specific sections (Refer to clause 10.8.1, figures 6 and 9); and
Consider Installation of a draw wire for any proposed cable installations
This method of installation minimises disruption to footpath and vehicular traffic and business premises
10.9 Reduced Cover Trenching
(eg Where Hard Digging/Obstacles Occur and/or conflict with another
Authorities/Utilities)
Refer to Appendix – F that specifies the requirements for reduced trench cover where hard
digging or obstacles occur This reduced cover trench arrangement can also be utilised where
the SA Power Networks asset is in conflict with another authorities/utilities‟ installation
For reduced cover trench arrangement, consider the following requirements:
Prior to using such reduced trench arrangement, a proposed scope of works shall be
presented to the relevant SA Power Networks Manager for approval;
Install cable markers at the start and finish at spacing of 30m (where practical) for the full
length of the reduced cover trench, Equivalent to Appendix - B of this document, for all areas including footpath reserve areas or private properties;
Trang 33 Note to be added to “As Constructed” drawing, making reference to contact SA Power
Networks before trenching in reduced cover trench;
Other Utilities such as telecommunications may go along side
SA Power Networks‟ assets in another trench to maintain clearances The affected utilities shall be notified of the reduced trench cover Evidence of this notification shall be
provided to SA Power Networks; and
Installations must also comply with all other requirements of this
TS-085
10.10 Underground Cables on Bridge Crossings
For cable requirements, on bridges refer to TS-100
10.11 Pit Installations
There are number of pits available in various sizes The Installed pit shall be of a size
appropriate for the purpose The designer also needs to be mind-full of clearances to the other
services and note that clearance to
water pipe lines infrastructure (e.g SA Water) from SA Power Networks LV pit shall be 1.0m Also, refer to clause 10.6 and figure 9 below
Where conduits are installed into the body of a pit, the conduit needs to be 25 to 50mm inside
the pit‟s body All conduit edges shall have no sharp edges
The Contractor shall cap all conduit entries, to stop the entry of foreign material between the
time of the conduit installation and the installation of SA Power Networks cables Refer to
clause 11.10.4 below and refer to TS100 for design information on service pillar and pit
Expanding foam or silicon should be utilised as a sealer at the conduit entry point into the wall
of a service pillar if the conduit is not a tight fit
FIGURE 9 TYPICAL CABLE AND CONDUIT ENTRY INTO JUNCTION PITS
Note
1 Refer to E1921 sht 2.1 for standard arrangements
2 Refer to E1921 sht 6.1 to 6.4 for assembly details
3 A P7 pit is preferred for LV cable junctions and service arrangements for approved below ground connections
4 The preference is for all conduits to enter at the ends of
a pit Conduit to finish 25mm - 50mm inside pit
CABLE & CONDUIT ENTRY INTO JUNCTION PITS
pit bottom for low
voltage cable entry
Trang 3410.12 Cable Location Markers
Wherever cables are laid in underground trenches in rural locations or across private property
then cable location markers are to be installed
to clearly identify the location of the underground cables
The cable location marker (stock item no - KS3722) is also to be installed to locate service
pits/pillars in both rural and residential land developments, where the development is likely to
remain unoccupied for an extended period or where the natural vegetation will prevent the
obvious identification of the SA Power Networks equipment
Refer to Appendix - B below for specific details of SA Power Networks required cable location marking systems
10.13 Trenchless/Directional Boring
Some trenching scenarios need to undertake the installation the installation of conduit using
trenchless boring technique Directional Drilling should only be considered in situations where
“Open Trenching” is not an option Good examples of this would be - but not limited to –
under rivers, under tram or train lines, in CBD areas where the road is full of services and does not provide an alignment for an open trench Trenchless/directional boring technology is
utilised where:
Open trenching is not suitable (or not an option) to the local conditions
The minimum depth needs to be 1.5m to ensure there is no groundswell above the conduit installation
The most suitable boring technique for a particular site will be dependent on the following
considerations:
Number and size of cables to be installed; Length required; Type of soil and condition;
Location accuracy required; Straight or curved profile/route required; and Restraints on
size of equipment used and/or work site access
When required, Install nylon draw ropes and seal the conduit ends, using suitable tapered
push-in polystyrene plugs
10.13.1 Requirements for Directional Boring
When utilising trenchless/directional boring technology consideration shall be given to the following requirements:
When installing more than one conduit in the bored hole, or the hole exceeds the outer diameter of the conduit by more than 25mm, then fill the resulting voids with a suitable approved slurry
When installing banks of conduits in a bore, install conduits in such a way when practicable that the conduit profile is the same at the entry and exit
The design and construction of a bore means polyethylene pipe is required
as per Table 9 and Table 10 in this document Also, consider the potential for cable de-rating for the deeper burial of cables and the minimum
allowable depth can be preferable
For SA Power Networks Telecommunications conduits that will only have Optic Fibre Cables installed, marker tape with tracer wires shall be
Trang 35Any trenchless bore installation requires a bore log of the final depths and locations to
be included on the “As Constructed” drawing as a permanent record of the installation
Refer to TS-100 for the directional bore drawing preparation detail Also, refer to
Appendix-C for “Example of Directional Bore Drawing” in this document
Further clarification can be obtained from the Facilities Records Coordinator through the SA Power Networks Project Manager
10.14 Hydro Vacuum Excavation
Hydro vacuum excavation can be a non-destructive excavation and can be a safer technique
compared to other excavation methods To ensure that an SA Power Networks asset is not
damaged the operator needs to aware that the maximum working pressure allowed for the
water excavator is 2000 pounds per square inch (psi) (13,790 kilopascals), as at higher
pressures it is possible to damage fibre optic cables (Reference Energy Australia N156)
In any case, the SA Power Networks cables shall not be left exposed without some form of
additional protection when the excavation site is left unsupervised When any proposed
excavation methods are utilised adjacent to SA Power Networks infrastructure, compliance
with NICC–404 is also required
The Hydro Vacuum Excavation technique could assist in:
Identifying an underground asset;
Digging a pole hole near poly-ethylene or poly vinyl chloride (PVC) pipelines, excavating safely across optic fibre and precise potholing;
Excavating in sensitive areas where traditional excavation machinery could cause major
damage;
Eliminating any costly damage or breakages; and
Minimising accidents involved in any type of mechanical excavation
11.0 CONDUITS and BENDS REQUIREMENTS
11.1 General
Installation of cables shall be in the conduits, under the following circumstances:
Road crossings;
Full length of pathways with restricted access (i.e., a pathway between fenced allotments);
Public lighting cables which are installed in independent trench to AS/NZS3000 and CLER Tariff lighting installations;
Retrospective undergrounding (i.e PLEC Projects); and/or
Trenching on private property and an easements where cables are vested in SA Power
Networks Refer to clause 12.0 below
11.2 Spare Conduit Provision
The Civil Contractor needs to be vigilant in ensuring that the appropriate number of conduits
are installed at a road crossing to accommodate all of the electrical cables PLUS any
continuous spare conduit requirements in the common service trench This will minimise future
on site works at the time the spare conduit is utilised
Trang 36The design and installation shall include spare conduit requirements as detailed in the
following clauses 11.2.1, 11.2.2 and 11.2.3 For more information on spare conduits
requirements and conduits layout in trench, refer to the relevant appendices
In some developments, the design specifies the installation of additional spare conduits above
the conduit requirements within the common service trench for the buried direct cables
It is important that additional spare conduits installed in the common service trench are
continuous with the spare conduits installed at road crossings If the installation of additional
spare conduit requirements is not continuous then SA Power Networks will issue a
noncompliance
11.2.1 Wherever an electrical cable is buried direct
(i.e in a Road Reserve)
The conduit installation needs to be such that any buried direct cable can be replaced
in a spare conduit
As an Example: There are three individual circuits of low voltage (3x150mm2) and one circuit of 300mm2 high voltage cable buried directly in a common service trench
In accordance with clause 11.5 - “Conduit Sizes”, the cables require the following
spare conduits as stated in Table 3A below:
TABLE 3A SPARE CONDUITS REQUIRED FOR ROAD RESERVE Application (Road Reserve)
Buried Directly
Spare Conduits Required
per Cable/per Phase)
Note for Table 3A:
1 Some LV single circuit and/or twin circuits have parallel cables, which shall
be considered as set of two cables; therefore, two spare conduits shall be required i.e one spare conduit per cable installed
11.2.2 When a cable is installed in a conduit
To ensure that future Civil works for SA Power Networks infrastructure is kept to a minimum; there is a requirement that where cables are to be installed in conduit, additional conduits are required to assist in cable replacement
Unless specified differently in the SA Power Networks specification the requirements are:
11.2.2.1 For a PLEC Project:
All cables shall be conduited Each installed conduit will have equivalent