Standards of living increase
The Australian/New Zealand Wiring Rules was recently amended for the second time. Dimi Kyriakou looks at the most important changes that electricians need to know about.
It’s called the ‘Industry Bible’ for a good reason – AS/NZS 3000:2007 Electrical Installations (known simply as the Wiring Rules) is an essential read for all members of the electrical industry.
This extends not only to electricians and electrical contractors, but also to design consultants, inspectors, regulators and industry training bodies as well as manufacturers, wholesalers and retailers of electrical equipment and accessories.
The current Wiring Rules were released in November 2007, with Amendment 1 being made in July 2009. Now, the document will receive further significant changes in Amendment 2.
Produced by the joint Standards Australia/Standards New Zealand Committee EL-001, the revised edition expands on issues relating to electrical installations, improves safeguards and addresses the needs and expectations of stakeholders.
While an article that details every change made in Amendment 2 would be quite extensive (not to mention a little boring), we have taken a snapshot of the main changes that every member of the electrical industry should be aware of and follow-up in the published Standard.
Language and wording
As is the case with most amendments, the main changes made to the Wiring Rules are predominately of an editorial nature. According to Keith Van der Zyden, a member of the EL-001 committee and Energy Safe Victoria audit manager, one of the most significant changes that electricians need to be mindful of when looking through the updated Standard are the definitions of ‘shall’ and ‘should’.
“The word ‘shall’ indicates the statement is mandatory, while the word ‘should’ indicates that the statement is a recommendation,” he says.
“Also, all equipment installed on a switchboard must be legibly and indelibly identified in English. You wouldn’t expect a Standard to have to say that, but seeing as we are so diversified in Australia, if it were written in a different language it may not be possible for other tradesmen, or even the home owner, to know what the equipment is and does.”
Green/green yellow sheathed conductors
While it is common knowledge that a green or green/yellow sheathed conductor should not be used for any purpose other than earthing, Keith says that some manufacturers have blurred the line between electrical safety and ‘marketing’ to use the external colour of the cabling to promote its use as a ‘green’ alternative for solar systems.
“The Wiring Rules only refers to the insulation of the conductor, not the sheathing, but there are currently cables being sold that sport green sheathing. The manufacturers can do this because, while the inference is there, the Wiring Rules don’t explicitly say it is not allowed.”
The relevant clause (1.7.2(f)) has been reworded to ensure that green or green/ yellow combination coloured insulation or sheathing of cables are not used for live conductors of consumer mains, sub mains and final sub circuits of installation wiring.
Residual-current devices (RCDs)
Amendment 2 to the Wiring Rules has clarified many of the existing clauses relating to RCDs.
“Where protection of final sub-circuits is required, RCDs shall be installed at the switchboard of which the final sub-circuit originates. That’s quite an important point that was passed in the draft,” Keith says.
Clause 188.8.131.52.1 was rewritten to ensure that where an RCD is incorporated into a socket-outlet or located adjacent to a socket-outlet and specifically intended for the protection of that socket-outlet (socket RCD or SRCD) the RCD shall interrupt all live (active and neutral) conductors.
Smoke detectors are now also regarded as lighting points.
The Federal Government’s troubled insulation scheme was a timely reminder that safety default clearances are absolutely necessary when it comes to recessed luminaires.
Where a barrier is used, that barrier is required to be manufactured in accordance with product Standard AS/NZS 5110 and is required to be fixed into position.
“What most people don’t realise is that temperatures of 90°C and above can cause pyrolysis and ignite – that is in close proximity to an unshielded recessed luminaire could catch fire. Your typical halogen downlight is 200°C plus. So, if a recessed luminaire is too close to timber in a ceiling you’re now looking at a fire situation. This is why the Wiring Rules also states a default clearance of 200mm,” Keith says.
“The best way for electricians to go about it is to install to the manufacturer’s installation instructions. If they’re not there, hand them back because you’ve got to protect yourself and the work you have completed.”
Where recessed luminaires are installed, a permanent and legible warning sign shall also be installed in the accessible roof space (i.e. the man hole) adjacent to the access panel in a position that is clearly visible to the person entering the space. The sign must comply with AS 1319 and contain the words:
Recessed lights have been installed in this roof space. To reduce the risk of fire DO NOT COVER the light fittings with thermal insulation or any other material unless in accordance with instructions provided by the light fitting or barrier manufacturer.
According to Keith, there is a lot of information about electrical installations in the gas and plumbing industry’s standards and regulations (i.e. AS 5601); however, information relating to gas appliances was not adequately covered in the Wiring Rules.
“If a gas inspector goes out to an installation and finds the socket outlet behind the gas appliance, he won’t connect the gas because their Standard says that socket outlet has to be in an adjacent cupboard,” he says.
“Fortunately for gas installers and plumbers, Amendment 2 will also include that information in the Wiring Rules.”
It states that a gas appliance connected to the electricity supply will have a means of electrical isolation that is adjacent to the appliance location and is accessible with the appliance in the installed position.
Previously there was some confusion as to whether or not the existing clause regarding a circuit for a fixed or stationary cooking appliance included induction and infrared cooking appliances. The clause (4.7.1) has been reworded to incorporate any type of electrical cooking appliance.
Air conditioning systems and heat pump systems
This section received one of the most significant new clauses in Amendment 2.
Air conditioning and heat pump systems incorporating a compressor shall now be provided with a lockable isolation switch installed adjacent to the unit. This switch must isolate all parts of the system, including ancillary equipment, from the same location.
This new clause was written for electricians to better understand the existing requirements in the Standard.
Swimming and spa pools
According to Keith, this section of the original Standard caused considerable confusion. It has now been reworded to ensure there is no potential for ‘step and touch’ electrocution.
“What this is trying to achieve is if you have a pool that has metal reinforcing, etc, an electrician is required to provide an accessible equipotential bonding point external to that pool so that any other metallic equipment around that pool zone can be equipotentially bonded together easily,” he says.
“The recommendation is to have the connection point located in a position that is accessible, with space for connections to be made after pool construction is complete. The location of the equipotential bonding point should be identifiable by markings on the switchboard at which the circuits supplying the pool or spa originate, or another permanent location.”
Installations in patient areas
AS/NZS 3003:2011 Electrical Installation – Patient Areas was first published on 1 April 2011 and updated later that same year.
In Amendment 2, there are now 26 locations classified as ‘body-protected electrical areas’ that fall under this definition, including operating theatres, hospitals, treatment rooms, chiropractic and physiotherapy treatment rooms, nursing homes and dental surgeries.
However, a grey area still exists as there are other locations (tattoo parlours and first aid treatment rooms on a construction site, for instance) that could also be classified as body protected electrical areas and should be wire as such.
The committee responsible for AS/NZS 3003 is currently reviewing this clause in order to provide clarification.
Generally, in body protected electrical areas, a final sub-circuit used to supply socket outlets shall not be used to supply electrical points in any other room, which means each individual room is required to have a minimum of one power circuit connected to a Type 1 10mA RCD. The Type 1 10mA RCD must be installed within the room so that it can be reset while the patient is under treatment.
In accordance with the Standard, a 30mA RCD cannot be installed upstream of a 10mA RCD as it is unable to discriminate.
The final word
There’s no doubt that the opportunity to revisit and update such an important Standard is necessary for the electrical industry, especially considering the Wiring Rules only outline the minimum requirements for installation and are always open to interpretation. Knowing what works and what doesn’t is never truly known until it has been tested out in the field.
As this article has been prepared as a guide for electricians to understand the changes announced within the updated Standard, we recommend that you purchase or download a copy of the published Amendment 2 to the Wiring Rules when it becomes available. See www.tradestuff.com.au for details.