T HR EL 20005 GU Guide to Above Ground Installation ... · T HR EL 20004 GU High Voltage AC and 1500 V DC Traction Power Supply Cables – Design and Construction Guide . T HR EL

Guide to Above Ground Installation Configurations for High Voltage AC and 1500 V DC Cables

T HR EL 20005 GU

Guide

Version 1.0

Issued date: 23 May 2018

© State of NSW through Transport for NSW 2018

T HR EL 20005 GU Guide to Above Ground Installation Configurations for High Voltage AC and 1500 V DC Cables

Version 1.0 Issued date: 23 May 2018

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You must not use or adapt this document or rely upon it in any way unless you are providing

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Standard governance

Owner: Lead Electrical Engineer, Asset Standards Authority

Authoriser: Chief Engineer, Asset Standards Authority

Approver: Executive Director, Asset Standards Authority on behalf of the ASA Configuration Control Board

Document history

Version Summary of changes

1.0 First issue

© State of NSW through Transport for NSW 2018 Page 3 of 20



Preface The Asset Standards Authority (ASA) is a key strategic branch of Transport for NSW (TfNSW).

As the network design and standards authority for NSW Transport Assets, as specified in the

ASA Charter, the ASA identifies, selects, develops, publishes, maintains and controls a suite of

requirements documents on behalf of TfNSW, the asset owner.

The ASA deploys TfNSW requirements for asset and safety assurance by creating and

managing TfNSW's governance models, documents and processes. To achieve this, the ASA

focuses on four primary tasks:

• publishing and managing TfNSW's process and requirements documents including TfNSW

plans, standards, manuals and guides

• deploying TfNSW's Authorised Engineering Organisation (AEO) framework

• continuously improving TfNSW’s Asset Management Framework

• collaborating with the Transport cluster and industry through open engagement

The AEO framework authorises engineering organisations to supply and provide asset related

products and services to TfNSW. It works to assure the safety, quality and fitness for purpose of

those products and services over the asset's whole-of-life. AEOs are expected to demonstrate

how they have applied the requirements of ASA documents, including TfNSW plans, standards

and guides, when delivering assets and related services for TfNSW.

Compliance with ASA requirements by itself is not sufficient to ensure satisfactory outcomes for

NSW Transport Assets. The ASA expects that professional judgement be used by competent

personnel when using ASA requirements to produce those outcomes.

About this document

This guide provides guidance to the suppliers in complying with the requirements of

T HR EL 20005 ST Above Ground Installation Configurations for High Voltage AC and

1500 V DC Cables.

This guide is a first issue.




Table of contents 1. Introduction .............................................................................................................................................. 6

2. Purpose .................................................................................................................................................... 6 2.1. Scope ..................................................................................................................................................... 6 2.2. Application ............................................................................................................................................. 6

3. Reference documents ............................................................................................................................. 6

4. Terms and definitions ............................................................................................................................. 7

5. Scope of T HR EL 20005 ST .................................................................................................................... 9

6. General requirements ............................................................................................................................. 9 6.1. Mechanical properties .......................................................................................................................... 10 6.2. Materials .............................................................................................................................................. 11 6.3. Environment ......................................................................................................................................... 12 6.4. Thermal expansion .............................................................................................................................. 12 6.5. Cable cleats ......................................................................................................................................... 14 6.6. Earthing and bonding ........................................................................................................................... 16 6.7. Accommodation of cable joints and terminations ................................................................................ 17 6.8. Separation from other services ............................................................................................................ 17

7. Fire life and safety ................................................................................................................................. 18

8. Cable trunking systems ........................................................................................................................ 19 8.1. Properties............................................................................................................................................. 19 8.2. Thermal insulation ............................................................................................................................... 19

9. Cable ducting systems ......................................................................................................................... 19

10. Properties of cable tray systems and cable ladder systems ............................................................ 20




1. Introduction The power supply to traction and other substations, railway stations, signalling systems and

other elements of the TfNSW heavy rail network is primarily provided by the RailCorp

distribution system. The RailCorp distribution system consists of both high voltage (HV) cables

and aerial lines with nominal voltages that vary between 11 kV and 132 kV. A small number of

feeders with a nominal voltage of 2 kV are still present in the existing network; however, these

feeders are gradually being phased out.

The RailCorp 1500 V dc traction power supply system contains cables with a rated voltage of

3.8/6.6 kV.

Refer to T HR EL 20004 ST High Voltage AC and 1500 V DC Traction Power Supply Cables –

Standards for Design and Construction for design and construction requirements of these

cables.

Refer to T HR EL 20001 ST High Voltage AC and 1500 V DC Traction Power Supply Cable

Requirements for the approved cable types and sizes.

The requirements for above ground installation configurations of high voltage ac and 1500 V dc

traction power supply cables are contained in T HR EL 20005 ST Above Ground Installation

Configurations for High Voltage AC and 1500 V DC Cables.

2. Purpose The purpose of this document is to provide guidance on the application of the requirements

specified in T HR EL 20005 ST.

2.1. Scope The scope of this document is to provide guidance and clarity around certain requirements

contained in T HR EL 20005 ST.

2.2. Application This guide applies to the same above ground electrical installation configurations as

T HR EL 20005 ST.

3. Reference documents The following documents are cited in the text. For dated references, only the cited edition

applies. For undated references, the latest edition of the referenced document applies.

International standards

EN 61914 Cable cleats for electrical installations © State of NSW through Transport for NSW 2018 Page 6 of 20



Australian standards

AS 2067 Substations and high voltage installations exceeding 1 kV a.c.

AS/NZS 2053.7 Conduits and fittings for electrical installations – Part 7: Rigid metal conduits

and fittings

AS/NZS 4296 Cable trunking systems

Transport for NSW standards

EP 20 00 03 01 SP HV and 1500 V DC Cables – Joints and Terminations

EP 99 00 00 08 SP Substations Fire Protection and Detection Standard

ESC 300 Structures System

ESC 340 Tunnels

T HR CI 12190 ST Service Installations within the Rail Corridor

T HR EL 00006 ST Electrical Power System Signage

T HR EL 20001 ST High Voltage AC and 1500 V DC Traction Power Supply Cable

Requirements

T HR EL 20004 GU High Voltage AC and 1500 V DC Traction Power Supply Cables – Design

and Construction Guide

T HR EL 20004 ST High Voltage AC and 1500 V DC Traction Power Supply Cable

Infrastructure – Standards for Design and Construction

T HR EL 20005 ST Above Ground Installation Configurations for High Voltage AC and 1500 V

DC Cables

Transport for NSW drawings

EL 0464562 Campbelltown – Glenlee – Main South 55.1 – 58.6km – 33kV Feeder 7M5

Upgrade – Cable Joint on GST Details

EL 0498788 Villawood – South Sydney Freight Line 24.6 to 25.4 Km – HV Aerial Lines &

Cables – 33kV Feeder 717 – Layout

SG 0144963 Steel Troughing – Lysaght Brownbuilt Pattern

Note: EL 0464562, EL 0498788 and SG 0144963 are not readily available. For

access, please contact [email protected]

4. Terms and definitions The following terms and definitions apply in this document:




AEO Authorised Engineering Organisation; a legal entity (which may include a Transport

Agency as applicable) to whom the ASA has issued an ASA Authorisation

ASA Asset Standards Authority

cable ducting system assembly comprising a ducting length and possibly other system

components to provide an enclosure for the accommodation and drawing in of insulated

conductors and cables and possibly the accommodation of other electrical equipment

(EN 50085-1)

cable ladder system assembly of cable supports consisting of cable ladder lengths and other

system components (EN 61537)

cable tray system assembly of cable supports consisting of cable tray lengths and other

system components (EN 61537)

cable trunking system a system of trunking lengths and components, used for the

accommodation and protection of cables (AS/NZS 4296)

distribution system (as defined in the Electricity Supply Act 1995) the electricity power lines

and associated equipment and electricity structures that are used to convey and control the

conveyance of electricity:

(a) to the premises of wholesale and retail customers, up to the connection point in relation to

the premises (which may or may not be situated on the building or land comprising the

premises), or

(a1) from the premises of former regulated offer customers or small customers that have a

complying generator installed and connected from the connection point to the premises, or

(b) to, from and along the rail network electricity system operated by, for or on behalf of Rail

Corporation New South Wales, Sydney Trains or Transport for NSW,

but does not include a transmission system or any lines, equipment and structures prescribed

by the regulations.

GLT ground line troughing

GST galvanised steel troughing

JOS judgement of significance

OHW overhead wiring

RailCorp the NSW Government's asset holding entity for the metropolitan heavy rail network

assets. RailCorp infrastructure includes rail infrastructure associated with the metropolitan

heavy rail network and excludes rail infrastructure that belong to the Sydney metro and light rail

networks




rail corridor the land between the boundary fences over which a railway line passes or, where

there are no fences, the extent of land owned, leased or otherwise utilised by the rail

operator/state

TfNSW Transport for New South Wales

trunking length the main component of a trunking system, consisting of a base and a

removable cover (AS/NZS 4296)

UGOH underground to overhead

underbridge refer to ESC 300 Structures System for the definition of underbridge

5. Scope of T HR EL 20005 ST T HR EL 20005 ST states the requirements for above ground installation configurations of high

voltage ac and 1500 V dc traction power supply cables for the TfNSW heavy rail network.

The scope of T HR EL 20005 ST covers cable installations that are not buried. Apart from

above ground cable installations in the open route, it also covers installations that are above the

'ground' level within an underground structure. For example, cable tunnels and cable pits are

generally underground structures, but typical cable support arrangements used inside these

structures are located above the 'ground' level within the structures.

6. General requirements T HR EL 20005 ST states the requirement that above ground cable installation configurations

are to comply with the requirements of T HR EL 20004 ST High Voltage AC and 1500 V DC

Traction Power Supply Cables – Standards for Design and Construction.

Particular attention is drawn to the requirements of T HR EL 20004 ST regarding prohibition of

ground line troughing and the restrictions on exposed above ground cable installations outside

of the heavy rail corridor.

Boundary fences may not always be located at the property boundary. Where an above ground

cable route is proposed, property title searches should be conducted in an early stage of design

development to ensure that the proposed cable route is located on TfNSW property within the

rail corridor. Property title searches should be conducted via the property division of the

operator and maintainer.

Above ground high voltage ac cable installation in secure environments outside of the open

route does not need to comply with AS 2067 Substations and high voltage installations

exceeding 1 kV a.c., with respect to the provision of robust metallic enclosures. Refer to

T HR EL 20005 ST Section 11 for examples of such environments.




6.1. Mechanical properties T HR EL 20005 ST specifies requirements for the following aspects:

• strength for withstanding loads of the cable support system

• mechanical protection against vehicle impact damage

These are addressed in Section 6.1.1 and Section 6.1.2 of this guide.

6.1.1. Strength for withstanding loads of the cable support system

The static weight, minimum bending radius and maximum sidewall bearing pressure applicable

to the cable should be obtained from the cable manufacturer. Particular care should be taken to

check that the cable is not subject to point loads around bends. To avoid compatibility issues,

transition pieces and coupling fittings from the same manufacturer of the straight support

lengths should be used as far as practicable.

The magnitude and duration of the fault current are specified in the power study relevant to the

project. Where a power study report is not available, the information should be obtained from

the network operator of the RailCorp distribution system, Sydney Trains. Enquiries should be

made to the Electrical Manager, Engineering and Systems Integrity of Sydney Trains.

Cable support systems should not be used as ladders, walkways or support for people.

However, if the cable support system has flat surfaces that a person can stand on, the weight of

persons should be considered by the designer in assessing the safe working load and

maximum deflection limit specified by the manufacturer. The number of persons that should be

included in the consideration should be based on a risk analysis and be compatible with the

area of the flat surface. Galvanised steel troughing (GST) with a flat cover is an example of

such a cable support system.

6.1.2. Vehicle impact damage

Locations with a high risk of vehicle impact damage to above ground cable installations include

the following:

• at and near rail corridor access gates

• along narrow vehicle access roads

• vehicle turning areas

• where there is a sharp bend in the roadway adjacent to the rail corridor

• transition arrangements between underground and above ground cable installations

Guardrails and bollards are typical means of providing additional mechanical protection in these

areas. See Figure 1 for an example installation.




Figure 1 - Example installation of additional mechanical protection for above ground cable installation

6.2. Materials T HR EL 20005 ST states requirements for metallic components, including those made of steel.




While the use of stainless steel grade 316 or better is mandatory for railway tunnels only, the

designer should consider the project environment for other applications. For example, stainless

steel should be used if water is expected to be present in a cable pit for extended time periods.

6.3. Environment Stations and structures such as bridges in the TfNSW heavy rail network may be heritage listed.

The designer should confirm the heritage status of a structure before proposing to have a cable

support system attached to the structure.

Refer to ESC 300 Structures System and T HR CI 12190 ST Service Installations within the Rail

Corridor for environmental requirements of structures and service installations.

6.4. Thermal expansion T HR EL 20005 ST specifies requirements for the following aspects:

• expansion joints of the cable support system

• cable support arrangement across structure expansion joints

• provision of slack in cable run between cable support points

These are addressed in Section 6.4.1 to Section 6.4.3 of this guide.

6.4.1. Expansion joints of the cable support system Where the maximum distance between expansion joints is not specified by the manufacturer of

the cable support system, it should be determined from the following factors:

• allowable movement at the expansion joint, as specified by the design of the joint

• temperature range

• coefficient of linear expansion of the material

The installer should take particular care in ensuring that free movement at the expansion joints

is not hindered by support posts and brackets, the cover retention device, and misalignment of

adjoining sections. Examples of incorrect installation practices are given in Figure 2 to Figure 5.




Figure 2 - Incorrect gap in expansion joint and movement restricted by strapping

Figure 3 - Expansion joint too close to support bracket


Figure 4 - Incorrectly installed expansion joint – Gap too large with no inset



Figure 5 - GST incorrectly supported under moving section

6.4.2. Cable support arrangement across structure expansion joints The number and design of expansion joints on a bridge are generally specific to the bridge. The

designer of the cable support system on the bridge should consult the bridge designer on the

locations and design of the structure expansion joints.

6.4.3. Provision of slack in cable run between cable support points T HR EL 20005 ST states the requirements for provision of slack in cable between cable

support points.

Where the cable is continuously supported, for example a three core cable in a GST installation,

the slack in the cable may be provided by 'snaking'.

Where cables are supported by cable cleats, the slack should be provided between adjacent

support points.

6.5. Cable cleats T HR EL 20005 ST states requirements for cable cleats and support structures.

The design of the support structure should be documented in civil design drawings as specified

in T HR EL 20004 GU High Voltage AC and 1500 V DC Traction Power Supply Cables – Design

and Construction Guide.




Where there is insufficient clearance between cable cleats and other components, the cable

cleats can be damaged. The damage may be caused as a result of the following:

• a trunking cover is forced onto the cable cleat during installation

• the cable cleat rubbing against a trunking cover due to vibration transferred into the cable

support system

An example of incorrect installation of a cable cleat in GST is shown in Figure 6 and Figure 7.


Figure 6 - Cable cleat protrudes above the GST



Figure 7 - The rubber at the top of the cable cleat was displaced and damaged as a result of inadequate clearance between the cleat and the GST cover

6.6. Earthing and bonding T HR EL 20005 ST states requirements for earthing.

For GST installations outside of substations, the earthing provided through foundations of

support posts, as shown in drawing EL 0498788 Villawood – South Sydney Freight Line 24.6 to

25.4 Km – HV Aerial Lines & Cables – 33kV Feeder 717 – Layout are generally satisfactory.

See Figure 8 for a partial copy of that drawing.

The metallic cable trays, cable ladders and trunking lengths within system substations should

be connected to the substation earthing grid.




Figure 8 - Part copy of drawing EL 0498788 showing GST support post

6.7. Accommodation of cable joints and terminations T HR EL 20005 ST states the requirements for accommodation of cable joints and terminations.

The available space for an above ground cable installation in the rail corridor is generally

limited. It is often necessary to have the joints of each core to be staggered to minimise the

space required at joint locations. See drawing EL 0464562 Campbelltown – Glenlee – Main

South 55.1 – 58.6km – 33kV Feeder 7M5 Upgrade – Cable Joint on GST Details for an example

of such an arrangement.

6.8. Separation from other services T HR EL 20005 ST states the requirements for separation from other services.




Where a GST housing HV ac or 1500 V dc cables is located below another GST, the vertical

distance between them should be greater than the width of the GST, but not less than 300 mm,

to allow for adequate maintenance access. See Figure 9 for an illustration of this vertical

separation.

Figure 9 - Vertical separation between GST

7. Fire life and safety T HR EL 20005 ST states requirements regarding fire life and safety.

While cable support systems inside railway tunnels have to be low smoke, low toxicity and

halogen free in accordance with ESC 340, it may be permissible to have some components that

do not comply with this requirement provided that such components are only present in small

quantities. If it is proposed to install a cable support system containing small quantities of non-

complying components, the designer should consult with the ASA Lead Electrical Engineer,

Lead Civil Engineer and Lead Stations and Buildings Engineer at an early stage of the design

process.

Fire retardant coating is typically applied to cables in existing installations. For new installations,

the required fire resistance should be provided through suitably fire rated cables and cable

support systems.




8. Cable trunking systems T HR EL 20005 ST states requirements for cable trunking systems.

Cable trunking systems for HV ac and 1500 V dc cables installed in the TfNSW heavy rail

network typically consist of 150 mm or 200 mm GST as shown in drawing SG 0144963 Steel

Troughing – Lysaght Brownbuilt Pattern. The covers are retained by stainless steel straps at a

nominal interval of 2 m minimum. This type of GST housing for HV ac and 1500 V dc cables has

provided reliable performance in the past, and may continue to be used in the TfNSW heavy rail

network without further testing. However, design AEOs should ensure that the design

configuration is suitable for the project requirements. For example, the capacity of the GST to

withstand the electromagnetic forces under fault conditions should be checked in the design

process.

Compliance of other types of cable trunking systems to T HR EL 20005 ST should be

demonstrated through results of appropriate tests in accordance to AS/NZS 4296 Cable

trunking systems.

8.1. Properties T HR EL 20005 ST states requirements for the properties of cable trunking systems used in

railway tunnels, cable tunnels and cable shafts.

Refer to Section 7 for the application of the halogen free requirement.

8.2. Thermal insulation T HR EL 20005 ST states requirements for the thermal insulation of cable trunking systems

Thermal insulation material, such as fibre reinforced cement, is sometimes provided along the

bottom and sides of GST as a mitigation measure against grass fires. The requirement for such

a mitigation measure should be determined from risk analysis of the installation environment.

Where required, the de-rating of the cable current capacity due to the installation of the thermal

insulation material should be determined in the design process.

9. Cable ducting systems T HR EL 20005 ST states requirements for cable ducting systems.

Cable ducting systems are not suitable for above ground cable installations due to the following

considerations:

• maintenance access to the cable is hindered as there is no access cover

• cable ducting systems with non-metallic conduits do not have the properties required for

above ground installation in the heavy rail environment




• the conduit sizes covered by AS/NZS 2053.7 Conduits and fittings for electrical installations

– Part 7: Rigid metal conduits and fittings are too small for most HV ac and 1500 V dc

traction power supply cables of the TfNSW heavy rail network

10. Properties of cable tray systems and cable ladder systems T HR EL 20005 ST states requirements for the properties of cable tray systems and cable

ladder systems.

Refer to Section 7 for the application of the halogen free requirement.


Documents

T HR EL 20005 GU Guide to Above Ground Installation ... · T HR EL 20004 GU High Voltage AC and 1500 V DC Traction Power Supply Cables – Design and Construction Guide . T HR EL