Standards Australia has released a second amendment to the AU/NZ Wiring Rules.

Published: 21 January 2013 Category: Technical Articles

The Amendment (at 45 pages) comprises a large number of matters that are generally of an editorial nature with the intetntion of clarifying an existing requirment or updating reference which have changed since publication of the standard. While a comparison of the amended and existing provision is recommended for a full understanding, the following matters are considered to have a more significant effect and a brief explanation is provided of the nature and reason for the change.

NECA Victoria provides members with free technical advice on the Wiring Rules and other Australian standards and regulatory requirements such as the Service and Installation Rules and Installation Safety Regulations.

At present there is a charge of $32.92 for an electornic copy of the Amendment only or $144.38 for the full standard incorporating Amendment 1 and Amendment 2.

Overview of the Amendments

REFERENCE	SUBJECT	EXPLANATION
1.7.2(f)	Cable colours	The prohibition of green, yellow and green/yellow to identify live cables has been clarified as applying to both the insulation and sheathing. Note that this only affects installation wiring and does not override equipment or switchboard wiring.
2.2.1.2	Common neutral	Sub-mains incorporating common neutral need not have linked switches/circuit-breakers.
2.3.3.1	Alternative supplies	Solar arrays or other alternative supplies to an installation need not be connected at main switchboard subject to meeting the conditions such as labeling provided in AS4777 (grid connected inverters) or AS/NZS3010 (generators)
2.6.2.2	Types of RCD	Common types of RCD extended to include Type I (electro-medical) and Type F (high frequency immunity)
2.6.3	Use of RCDs	New Zealand requirements for 10mA (Type A or Type I) RCDs in schools altered. Type I RCDs use for home medical equipment extended from dialysis equipment to align with AS/NZS3003.
3.4.1 4.2.2.7	Thermal insulation	New Zealand requirement in domestic installations for cable current carrying capacity to be determined as being in thermal insulation.
Table 3.7	Separation of underground services	Exception to separation from the earth electrode where the metal gas and water services are bonded within the installation.
4.4.2.2(d)	Socket-outlet fixing	Exception to fixing socket-outlets installed for light fittings or appliances, under the conditions formerly provided in the Frequently Asked Questions (FAQ).
4.5.2.3	Downlights	This is in response to the long standing concern with the potential for fires from overheated downlights, particularly of the common 50W halogen type, and has been prepared in conjunction with changes to lighting equipment standards and thermal insulation installation standards. There are three alternative compliance methods to manage the risk of fire from contact with thermal insulation or combustible building materials: a certified luminaire (eg New Zealand Classes IC-F and IC); a combination of luminaire and a certified barrier; minimum clearnaces (50-200mm) that may require a barrier to maintain. A warning notice is also required to remind householders that thermal insulation is not to cover the downlight.
4.7.1 4.18.1	Switches for cooking appliances	Switches required for cooking appliance circuits are required to be marked to identify the appliance. Switches isolatiing gas/electric appliances are to be double-pole, in accordance with gas appliance installation standard AS5601
4.18.1 Figs 4.10 & 4.11	Gas appliances	New clause summarising typical provisions for electrical connection and the creation of hazardous gas atmospheres that limit the selection and installation of electrical equipment.
4.19	Air-conditioners	New clause clarifying isolating switch provisions including common control for both parts of split system PAC.
5.3.5.2	MEN connection size	On large switchboards the MEN connection may be determined as for an earth conductor which will be considerably smaller than the consumers main neutral.
5.4.8	Variable speed drives	New Clause overview of risk from VSDs generating voltages on earthed equipment. The clause will need further work in next edition to become meaningful.
5.6.2.6	Swimming pool bonding	Restructured clause clarifying parts to be bonded and new requirement for a connection point to be installed in an accessible position during pool construction.
7.2.1.4	Lifts	Exception from safety service requirements for lifts incorporating means to prevent entrapment on power failure. Restores exception incorrectly removed in Amendment 1.
7.3.2 Fig 7.5 7.3.8.2.3	PV systems	References new standard AS4777 covering grid connected inverters and improved schematics and notes on alternative supply system connections to installation. The nominal voltage at the point of supply must not be more than 230/400V+10%
7.3.4.1	Generator Isolator	Isolation switch may be located at the generator system (as present) or subject to securing means if located remotely.
7.7	Hazardous areas	New AZ/NZS60079 series standards apply to the classification of hazardous areas, and the selection and installation of electrical equpment in those areas.
Table C1	Maximum demand of lifts	The contribution of Lifts in home unit installations are to be included in the maximum demand calculation of the consumers mains in addition to submains.
Table C6	Cable ratings	Correction to simplified ratings assigned to 6mm2 three-phase cable.
Appendix E	NCC/BCA and NZBC	Updated summaries of the provisions of national building codes that may affect electrical installations.
Appendix F	Surge protection devices	Updated selection and installation provisions for SPDs in accordance with AS/NZS1768, Lightning protection. Circuit-breaker or fuse providing short-circuit protection of SPD should be as specified by SPD manufacturer to ensure optimal operation rather than nominal 32A.