1General electrical requirements#

1.1Introduction#

These requirements set out the electrical design criteria that must be used for all Transport and Main Roads electrical installations, both new and modifications to existing installations – in particular, road lighting, traffic signals and Intelligent Transport Systems (ITS). It is not intended that existing installations that complied with AS/NZS 3000 Electrical Installations (known as the Australian / New Zealand Wiring Rules) when they were installed be changed to meet these design criteria; however, the Electrical Safety Act 2002 requires electrical installations to be electrically safe.

Compliance with AS/NZS 3000 is mandatory and frequent reference is made to the requirements therein. Compliance requirements include:

correct discrimination and load / circuit protection / cable selection combination
cable current carrying capacity
appropriate cable short-circuit withstand capacity
circuit voltage drop, and
earth fault loop impedance.

Designers must make themselves familiar with the conditions and requirements at the site for which they are carrying out designs.

Prior to commencing design, designers must verify that they have the current version of this document.

This document is set out in the following sections:

Section 1 General electrical requirements
Section 2 Road lighting requirements
Section 3 Traffic signal requirements
Section 4 Intelligent Transport Systems requirements
Section 5 Residual current device protection
Section 6 Surge protection
Section 7 Commentary
Section 8 Multidisciplinary projects

Unless otherwise stated, the principles of Sections 1 and 8 apply to the other sections.

1.2Scope#

The intent of this manual is to provide designers with the design philosophy required for electrical design within Transport and Main Roads infrastructure so that consistent and standardised designs can be achieved. While every attempt has been made to make it comprehensive, it is acknowledged that engineering design requires customisation for any particular installation. Engineering judgement is required to apply these principles to project-specific specifications.

Where departure from these requirements is deemed necessary for a particular project, approval must be given by the Director (Intelligent Transport Systems and Electrical).

1.3Abbreviations and definitions#

The following abbreviations, terms and definitions apply to this manual.

Table 1.3(a) - Abbreviations

Abbreviation	Description
A	Ampere
AEMO	Australian Energy Market Operator
AC, also ac	Alternating current
AS	Australian Standard
AS / CA	Australian Standard / Communications Alliance
AS / NZS	Australian and New Zealand Standard
CMA	Combination mast arm
CMS	Central Management System
CSA	Cross-sectional area
DB	Distribution board
DC, also dc	Direct current
dv / dt	Rate of change of voltage
EFLI	Earth fault loop impedance
ELV	Extra low voltage
e.m.f.	electromotive force
ESR	Electrical Safety Regulation 2013
GDT	Gas discharge tube
HDPE	High density polyethylene
HID	High intensity discharge
HPS	High pressure sodium
HRC	High rupture capacity
IP	Ingress protection
ITS	Intelligent Transport Systems
JUP	Joint use pole
LED	Light emitting diode
LV	Low voltage
m	Metre
MA	Mast arm
MCB	Miniature Circuit Breaker
MEN	Multiple earthed neutral
MOV	Metal oxide varistor
MRTS	Transport and Main Roads Technical Standard
ms	Millisecond
MSB	Main switch board

Abbreviation	Description
MSPD	Multiservice Surge Protective Device
NEM	National Electricity Market
PEN	Combined protective earth and neutral conductor
PSCC	Prospective short circuit current
PVC	Polyvinylchloride
RCBO	Residual current breaker with overload
RCCB	Residual current circuit breaker
RCD	Residual current device
rms	Root mean square
RPDM	Road Planning and Design Manual
RPEQ	Registered Professional Engineer Queensland
s	Second
SAD	Silicon avalanche diode
SD	Standard Drawings
SDI	Single core double insulated
SO	Socket outlet
SOA	Standing offer arrangement
SPD	Surge protection device
SRF	Surge reduction filter
TN	Technical Note
TPE	Thermoplastic elastomer
TRUM	Traffic and Road Use Management manual
TSC	Traffic signal controller
TSG	Triggered spark gap
UPS	Uninterruptable power supply
UPVC	Unplasticised polyvinylchloride
URD	Underground Residential Distribution
XLPE	Cross linked polyethylene

Table 1.3(b) – Definitions of terms

Term	Definition
Connected load	Sum of maximum running loads for all electrical equipment, including devices connected via socket outlet
Consumers mains	The conductors between the point of supply and the main switchboard
Dangerous potential	A prospective touch voltage exceeding 50 V ac or 120 V ripple-free dc
Disconnect time	The maximum time allowable for a protection device to open the circuit and clear an active-to-earth fault

Discrimination: Circuit protection will discriminate if the device closest to the fault clears the fault before the upstream protection activates, for all values of fault current expected at the point. Discrimination between devices protecting circuits is to minimise loss of supply to other circuits in the event of a fault on one circuit.
Extra low voltage: Voltage not exceeding 50 V ac or 120 V ripple-free dc
Field cabinet: Telecommunications field cabinet in accordance with MRTS201, and/or an enclosure associated with an ITS device
Link Switchboard: A switchboard that is used as an intermediate switchboard between the point of supply and ITS switchboards where long distances are involved. A fuselink smaller than the Electricity Entity fuselink is used in the link switchboard to reduce cable size for EFLI requirements. Link Switchboard – enclosed in conductive metal – refer SD1687 and SD1688 Note that the photocell and contactor system is not required.
Low voltage: Voltage exceeding ELV but not exceeding 1000 V ac or 1500 V dc
Point of supply: The junction of the consumers mains with the conductors of an electricity distribution system
Socket outlet: A device for fixing or suspension at a point, and having contacts intended for making a detachable connection with the contacts of a plug
Submains: A circuit originating at a switchboard to supply another switchboard (note that each re-openable joint directly supplying a road lighting pole is considered to be a main switchboard)
Switchboard: An assembly of circuit protective devices, with or without switchgear, instruments or connecting devices, suitably arranged and mounted for distribution to, and protection of, one or more submains or final subcircuits or a combination of both. Pillar mounted switchboard – enclosed in insulated plastic or fibreglass – refer SD1430 Top mounted switchboard – enclosed in conductive metal – refer SD1627 Metered switchboard – enclosed in conductive metal – refer SD1687 and SD1688 Traffic signal switchboard – enclosed in conductive metal – refer type approved manufacturer’s drawings ITS switchboard – enclosed in conductive metal – refer SD1689 and SD1690

Note that other definitions within the ESR and AS/NZS 3000 also apply.

1.4Legislation and standards#

1.4.1Professional Engineer’s Act 2002#

Designers must comply with the requirements of the Professional Engineers Act 2002. Completed designs must comply with the requirements of the Electrical Safety Act 2002 and subordinate legislation.

Attention is drawn to the requirements of the Professional Engineers Act 2002 section 115 as to who may carry out professional engineering services. Only a practising professional electrical engineer or a person under the direct supervision of a practising professional electrical engineer who is responsible for the electrical services may carry out the electrical services.

A person carries out professional engineering services under the direct supervision of a practising professional engineer only if the engineer directs the person in the carrying out of the services and oversees and evaluates the carrying out of the services by the person.

Professional engineering service means an engineering service that requires, or is based on, the application of engineering principles and data to a design, or to a construction, production, operation or maintenance activity, relating to engineering. As the design principles that follow in this manual require engineering judgement in their application, the requirement of the Professional Engineers Act 2002 for these engineering services to be carried out by a practising electrical engineer or under the direct supervision of a practising electrical engineer must be complied with.

1.4.2Referenced documents#

Clarification of the referenced including regrouping in logical order adding Standard Drawing references and including definitions for switchboards.

The referenced documents include the latest revisions and amendments.

The following documents are referenced in this manual:

Table 1.4.2(a) – Legislation (including subordinate legislation)

Reference	Title
Electrical Safety Act	Electrical Safety Act 2002
Electrical Safety Code of Practice	Electrical Safety Code of Practice 2010
Electricity Act	Electricity Act 1994
Electricity Regulation	Electricity Regulation
Professional Engineers Act	Professional Engineers Act 2002

Table 1.4.2(b) – Transport and Main Roads Technical Documents

Reference	Title
DDPSM	Drafting and Design Presentation Standards Manual
MRTS01	Introduction to Technical Specifications
MRTS50	Specific Quality System Requirements
MRTS91	Conduits and Pits
MRTS92	Traffic Signal and Road Lighting Footings
MRTS93	Traffic Signals
MRTS94	Road Lighting
MRTS97	Mounting Structures for Roadside Equipment
MRTS201	General Equipment Requirements
MRTS210	Provision of Mains Power
MRTS226	Telecommunications Field Cabinets
MRTS228	Electrical Switchboards
MRTS234	Communications Cables
MRTS256	Power Cables
MRTS257	Feeder Cable and Loop Cable for Vehicle Detector
MRTS259	Transportable Generator
RPDM Vol 5 2nd Ed	Road Planning and Design Manual 2nd edition Volume 5 Intelligent Transport Systems
RPDM Vol 6 2nd Ed	Road Planning and Design Manual 2nd edition Volume 6 Lighting
SD1423	Traffic signals –Traffic signal controller base installation details
SD1430	Road lighting – Switchboard pillar mounted
SD1623	Road lighting – Switchboard typical layout and circuit diagram MEN system
SD1627	Road lighting – Switchboard top mounted
SD1628	Road Lighting – Post – Top mounted switchboard
SD1637	Road Lighting – Underpass lighting wiring details
SD1676	Road lighting – Switchboard typical pillar layout
SD1678	Traffic Signals / Road Lighting – Joint use pole electrical wiring schematic Rate 2
SD1679	ITS – Telecommunications field cabinet base installation details
SD1686	Road lighting – Switchboard assembly details
SD1687	Road lighting – Metered switchboard assembly details single phase
SD1688	Road lighting – Metered switchboard assembly details three phase
SD1689	ITS – Switchboard typical layout and circuit diagram MEN system
SD1690	ITS – Switchboard assembly details pole / top mounted
SD1699	Traffic signals / Road lighting / ITS – Parts list
SD1707	Road Lighting – Base plate mounted pole mounted on bridges wiring details
SD1771	ITS IPRT network – PSC MK3 Controller Additional Power Outputs Via RCD Protected G.P.O
SD1772	ITS IPRT network - PSC MK1 and 2 Controller Additional Power Outputs Via RCD Protected by G.P.O.

Reference	Title
SD1773	ITS IPRT network - PSC MK3 Controller with Tophat Additional Power Outputs Via RCD Protected by G.P.O.
SD1774	ITS IPRT network - PSC MK1 and 2 Controller with Tophat Additional Power Outputs Via RCD Protected by G.P.O.
SD1775	ITS IPRT network - PSC MK1 and 2 Controller Additional Power Outputs Protected by G.P.O. Via RCD Optional Field Processor Location
SD1776	ITS IPRT network - PSC MK3 Controller Additional Power Outputs Via RCD Protected G.P.O. Optional Field Processor Location
SD1777	ITS IPRT network - Tyco Eclipse Controller Additional GPO's Via Existing RCD GPO Plus Communications Equipment
SD1778	ITS IPRT network - Tyco Eclipse Controller with Tophat Additional GPO's Via Existing RCD GPO Plus Communications Equipment
SD1779	ITS IPRT network - ATS Alfa 16 Controller with Tophat Additional GPO's Via New RCD GPO Plus Communications Equipment
TN158	Guide to the Use of LED Road Lighting Luminaires (including LED Luminaire Selection Guide)
TN159	Treatment of Under-depth Underground Wiring Systems (UWS) in Brownfield Installations
TN172	36-core Multicore Cable for Traffic Signal Installations
TRUM Vol 4	Traffic and Road Use Management manual Volume 4 ITS and Electrical Technology Manual

Table 1.4.2(c) – Standards

Reference	Title
AS 1222.1	Steel conductors and stays – Bare overhead – Galvanized (SC / GZ)
AS 1222.2	Steel conductors and stays – Bare overhead – Aluminium clad (SC / AC)
AS 1307.2	Surge arresters Part 2: Metal-oxide surge arresters without gaps for a.c. systems
AS 1531	Conductors – Bare overhead – Aluminium and aluminium alloy
AS 1746	Conductors – Bare overhead – Hard drawn copper
AS 3607	Conductors – Bare overhead, aluminium and aluminium alloy – Steel reinforced
AS 4070	Recommended practices for protection of low-voltage electrical installations and equipment in MEN systems from transient overvoltages
AS 4262.1	Telecommunication overvoltages – Part 1: Protection of persons
AS 4262.2	Telecommunication overvoltages – Part 2: Protection of equipment
AS 60038	Standard voltages
AS 60127-2	Miniature fuses, Part 2: Cartridge fuse-links
AS 60269	Low-voltage fuses General requirements
AS 60269	Low-voltage fuses
AS/CA S009	Installation requirements for customer cabling (Wiring rules)
AS/NZS 1158	Lighting for roads and public spaces
AS/NZS 1768	Lightning protection
AS/NZS 2053	Conduits and fittings for electrical installations
AS/NZS 2276.1	Cables for traffic signal installations – Part 1 Multicore power cables
AS/NZS 2276.2	Cables for traffic signal installations – Part 2 Feeder cable for vehicle detectors
AS/NZS 2276.3	Cables for traffic signal installations – Part 3: Loop cable for vehicle detectors
AS/NZS 2293.1	Emergency escape lighting and exit signs for buildings – Part 1: System design, installation and operation
AS/NZS 3000	Electrical Installations (known as the Australian / New Zealand Wiring Rules)
AS/NZS 3008.1.1	Electrical installations – Selection of cables – Part 1.1: Cables for alternating voltages up to and including 0.6 / 1 kV – typical Australian installation conditions
AS/NZS 3111	Approval and test specification – Miniature overcurrent circuit-breakers
AS/NZS 3112	Approval and test specification – Plugs and socket outlets
AS/NZS 3190	Approval and test specification – Residual current devices (current operated earth-leakage devices)
AS/NZS 3506.1	Electric cables – Cross linked polyethylene insulated – Aerial bundled – For working voltages up to and including 0.6 / 1 (1,2) kV Part 1 Aluminium conductors
AS/NZS 3506.2	Electric cables – Cross linked polyethylene insulated – Aerial bundled – For working voltages up to and including 0.6 / 1 (1,2) kV Part 2: Copper conductors
AS/NZS 3808	Insulating and sheathing materials for electric cables
AS/NZS 3835.1	Earth potential rise – Protection of telecommunications network users, personnel and plant – Part 1: Code of practice
AS/NZS 3835.2	Earth potential rise – Protection of telecommunications network users, personnel and plant – Part 2: Application guide
AS/NZS 4026	Electric cables – For underground residential distribution systems
AS/NZS 4961	Electric cables – Polymeric insulated – For distribution and service applications (Supplements AS/NZS 4026)
AS/NZS 5000.1	Electric cables — Polymeric insulated – Part 1: For working voltages up to and including 0.6 / 1 (1.2) kV
AS/NZS 5000.2	Electric cables — Polymeric insulated – Part 2: For working voltages up to and including 450 / 750 V
AS/NZS 60479.1	Effects of current on human beings and livestock – Part 1: General aspects
AS/NZS 60898.1	Electrical accessories – Circuit breakers for overcurrent protection for household and similar installations – Part 1: Circuit breakers for a.c. operation
AS/NZS 60898.2	Circuit-breakers for overcurrent protection for household and similar installations – Part 2: Circuit-breakers for a.c. and d.c. operation

Reference	Title
AS/NZS 60950.1	Information technology equipment – Safety – General requirements
AS/NZS 61000.4.5	Electromagnetic compatibility (EMC) – Part 4.5: Testing and measurement techniques – Surge immunity test
AS/NZS 61008.1	Residual current operated circuit-breakers without integral overcurrent protection for household and similar uses (RCCBs) – Part 1: General rules
AS/NZS 61009.1	Residual current operated circuit-breakers with integral overcurrent protection for household and similar uses (RCBOs) – Part 1: General rules
AS/NZS 61386	Conduit systems for cable management
AS/NZS IEC 60947.3	Low-voltage switchgear and control gear – Part 3 Switches, disconnectors, switch-disconnectors and fuse-combination switches
AS/NZS IEC 60947.4.1	Low-voltage switchgear and control gear – Part 4.1: Contactors and motor-starters — Electromechanical contactors and motor-starters
AS/NZS ISO 31000	Risk management – Principles and guidelines
ENA EG1	2006 Substation Earthing Guide
HB 301	Electrical installations – Designing to the Wiring rules
IEC 61200-413	Electrical installation guide – Part 413: Protection against indirect contact – Automatic disconnection of supply
IEC 61643 11	Low-voltage surge protective devices – Part 11: Surge protective devices connected to low-voltage power systems – Requirements and test methods
IEC 61643 12	Low-voltage surge protective devices – Part 12: Surge protective devices connected to low-voltage power distribution systems – Selection and application principles
IEC 61643 22	Low-voltage surge protective devices – Part 22: Surge protective devices connected to telecommunications and signalling networks – Selection and application principles
IEC 61643-21	Low voltage surge protective devices – Part 21: Surge protective devices connected to telecommunications and signalling networks – Performance requirements and testing methods
SAA HB113	Residual current devices – What they do and how they do it
UL 1449	Standard for Surge Protective Devices
UL 497	Standard for Protectors for Paired-Conductor Communications Circuits

This document and these standards contain the minimum design requirements.

1.5Design certificate#

Each electrical design must be accompanied by an electrical design certificate similar to the following:

Electrical design certificate
Electrical installation
District
Road Number
Plan Number
Details of work
I certify that this electrical design has been carried out in accordance with the requirements of the Professional Engineers Act 2002 and the design is in accordance with the requirements of the Electrical Safety Act 2002 and the Wiring Rules.

Registered Professional Engineer Queensland (Electrical) by whom the electrical design was carried out
Name
Signature
RPEQ Number
Company
Address
Telephone number	Date