T HR SC 01040 SP
Specification
6 OHM Track Resistor
Version 1.0
Issued date: 09 July 2015
Important Warning
This document is one of a set of standards developed solely and specifically for use on public transport assets which are vested in or
owned, managed, controlled, commissioned or funded by the NSW Government, a NSW Government agency or a Transport Agency
(as defined in the Asset Standards Authority Charter). It is not suitable for any other purpose.
You must not use or adapt it or rely upon it in any way unless you are authorised in writing to do so by a relevant NSW Government
agency. If this document forms part of a contract with, or is a condition of approval by a NSW Government agency, use of the document
is subject to the terms of the contract or approval.
This document may not be current. Current standards are available for download from the Asset Standards Authority website at
www.asa.transport.nsw.gov.au.
© State of NSW through Transport for NSW
T HR SC 01040 SP
6 OHM Track Resistor
Version 1.0
Issued date: 09 July 2015
Standard governance
Owner:
Lead Signals and Control Systems Engineer, Asset Standards Authority
Authoriser:
Principal Manager Network Standards and Services, Asset Standards Authority
Approver:
Director, Asset Standards Authority on behalf of the ASA Configuration Control Board
Document history
Version
Summary of Changes
1.0
First issue.
For queries regarding this document,
please email the ASA at
standards@transport.nsw.gov.au
or visit www.asa.transport.nsw.gov.au
© State of NSW through Transport for NSW
T HR SC 01040 SP
6 OHM Track Resistor
Version 1.0
Issued date: 09 July 2015
Preface
The Asset Standards Authority (ASA) is an independent unit within Transport for NSW (TfNSW)
and is the network design and standards authority for defined NSW transport assets.
The ASA is responsible for developing engineering governance frameworks to support industry
delivery in the assurance of design, safety, integrity, construction, and commissioning of
transport assets for the whole asset life cycle. In order to achieve this, the ASA effectively
discharges obligations as the authority for various technical, process, and planning matters
across the asset life cycle.
The ASA collaborates with industry using stakeholder engagement activities to assist in
achieving its mission. These activities help align the ASA to broader government expectations
of making it clearer, simpler, and more attractive to do business within the NSW transport
industry, allowing the supply chain to deliver safe, efficient, and competent transport services.
The ASA develops, maintains, controls, and publishes a suite of standards and other
documentation for transport assets of TfNSW. Further, the ASA ensures that these standards
are performance-based to create opportunities for innovation and improve access to a broader
competitive supply chain.
This document describes the requirements for ac track resistors used in railway signalling
applications.
This document has been developed from the RailCorp document SPG 1040 6 OHM Track
Resistor, Version 1.1 and has been reviewed and approved by the Asset Standards Authority.
This ASA specification supersedes RailCorp document SPG 1040 and is a first issue.
© State of NSW through Transport for NSW
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T HR SC 01040 SP
6 OHM Track Resistor
Version 1.0
Issued date: 09 July 2015
Table of contents
1.
Introduction .............................................................................................................................................. 5
2.
Purpose .................................................................................................................................................... 5
2.1.
Scope ..................................................................................................................................................... 5
2.2.
Application ............................................................................................................................................. 5
3.
Reference documents ............................................................................................................................. 5
4.
Terms and definitions ............................................................................................................................. 5
5.
Requirements ........................................................................................................................................... 6
5.1.
Life expectancy ...................................................................................................................................... 6
6.
Rating ........................................................................................................................................................ 6
7.
Adjustment requirements ....................................................................................................................... 6
8.
Termination of wiring .............................................................................................................................. 6
9.
Wiring ........................................................................................................................................................ 7
10. Insulation .................................................................................................................................................. 7
11. Dimensions .............................................................................................................................................. 7
11.1.
Mounting ............................................................................................................................................ 7
12. Unit labelling ............................................................................................................................................ 7
© State of NSW through Transport for NSW
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T HR SC 01040 SP
6 OHM Track Resistor
Version 1.0
Issued date: 09 July 2015
1.
Introduction
This equipment specification details the requirements for the design and fabrication of a variable
resistor module to be used in a track circuit application. As such they are known colloquially as
ac track resistors.
The resistor module is comprised of a variable resistor/s, adjustment slider, terminals and
mounting frame.
The resistor module may be used in other non-electronic railway signalling applications.
2.
Purpose
The purpose of this specification is to detail the requirements of a variable resistor module
designed to fit within a standard footprint on an equipment rack inside a signalling equipment
location.
The variable resistor module forms part of a feed arrangement for single and double Rail 50 Hz
track circuits.
While the primary use for this module is intended for track circuits, it may be used for other
non-electronic Railway Signalling applications.
2.1.
Scope
The scope of this document covers the design, fabrication and assembly aspects only. It does
not extend to the application of where and how these resistors are intended to be deployed nor
does it address any installation requirements such as allowances for heat dissipation.
2.2.
Application
The intended use of this document is to detail the design, fabrication and assembly
requirements for a 6 Ohm variable track resistor module. As such the intended audience for this
document are those in the design, manufacture and supply of electrical modules made from
standard and some bespoke design elements.
3.
Reference documents
No other standards or specifications are referenced in this document
4.
Terms and definitions
track resistor a variable 6 Ohm resistor used in 50Hz single and double rail track circuits. The
role of this resistor is to control the phase angle to a phase sensitive vane relay. While its
primary use is in track circuits, it may be used for other railway signalling applications.
© State of NSW through Transport for NSW
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T HR SC 01040 SP
6 OHM Track Resistor
Version 1.0
Issued date: 09 July 2015
5.
Requirements
A high level of workmanship and quality is necessary to ensure reliability and a preference will
be made for units with conservative ratings.
The resistors shall be wound on grooved ceramic formers to ensure linearity of winding.
All materials used in the construction of these units should be suitably treated against corrosion
and shall not be affected by heat or water or promote fungal growths.
5.1.
Life expectancy
The design of the resistor module shall be such so as to achieve a minimum life expectancy of
30 years.
6.
Rating
The nominal value of the resistors shall be 6 ohm continuously adjustable down to 0.25 ohms.
The use of two adjustable resistors is permitted.
The resistors shall have a capability of passing 20 A through any leg of the resistor at any value
of resistance.
7.
Adjustment requirements
The adjustment method shall be simple and should not cause hot spots on the adjuster at full
load because of small contact area. A standard resistor adjustment band is not considered
suitable because of the frequency of use and reliability required. Contact pressure of the
adjuster for the resistor should not be affected by vibration which will be prevalent during the
service life of the unit. Adjustment of resistor in service should not cause injury to the user as a
result of excessive heat. A terminating point should be made available in the adjuster for
terminating a cable connection.
8.
Termination of wiring
Terminations on the resistor should be well clear of all metal work and should not be positioned
such that wiring could be entangled or suffer heat damage. Terminals for connecting to the
resistor should be nickel plated brass M6 metric coarse threaded studs nuts, which shall be
firmly secured using locking nuts. A connection stud shall be made available on the adjustment
leg.
© State of NSW through Transport for NSW
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T HR SC 01040 SP
6 OHM Track Resistor
Version 1.0
Issued date: 09 July 2015
9.
Wiring
All wiring shall be suitably rated as fire resistant and should be suitably terminated on
non-insulated lugs and laid between nickel plated brass washers. Soldered connections
anywhere on the unit are not permitted. Indent crimping is not an approved method of
terminating crimp lugs.
10.
Insulation
Mounting and termination of the resistors shall be free from earth. Wiring terminations shall be
insulated from the frame of the unit.
Any insulation used within the module shall take into account the heat rise of the resistors
themselves and degradation due to long term heat exposure.
11.
Dimensions
The overall dimensions should not exceed 200 mm long, 150 mm wide and 120 mm high.
11.1.
Mounting
Mounting of the units should be on centres of 115 mm vertical and 105 mm horizontal with
7 mm mounting holes.
12.
Unit labelling
The manufacturer should have an identifying nameplate which shall be made of a non-corrosive
material not affected by heat firmly and permanently affixed to the unit.
The following information is required to appear on the nameplate:
•
manufacturers name
•
rating of the unit and its resistance
•
serial number including month and year of manufacture of the unit
•
packaging of the unit should be individual and the following information should be included
on the outside of the case:
ᴑ
the order number
ᴑ
description of the item, for example, 6 ohm track resistor
© State of NSW through Transport for NSW
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