flemhea brandea dawannah
Norine Wiltshire
Starting on January 1, 2019, the mandatory implementation of the wiring regulations is crucial for electricians, inspectors, and regulatory authorities. These regulations outline safety requirements for electrical installations in both Australia and New Zealand.
Effective from the specified date, adherence to the updated wiring regulations will be compulsory, in accordance with the relevant State laws. The 2018 edition of the "Electrical Installations (Australian/New Zealand Wiring Rules 3000:2018)" is now accessible, having been formulated through collaboration between Standards Australia, industry professionals, and government entities.
Alterations: Alterations to electrical installations shall not cause any portion of the original electrical installation, or connected electrical equipment, to: (a) carry excessive currents or sustain excessive voltages; or (b) be used in any manner that is not in accordance with AS/NZS 3000:2018.
Repairs: Repairs to existing electrical installations or their parts may be performed using methods, fixtures and fittings that were acceptable when that part of the electrical installation was originally installed or with methods, fixtures and fittings currently available as direct replacement, provided that the methods satisfy the fundamental safety principles of this Standard.
Clause 2.9 describes the requirements for protective equipment such as arc fault detection devices (AFDDs), which may be used to protect against the effects of arc faults in final subcircuits. AFDDs are required to comply with IEC 62606, and have a load current rating no less than that of the associated protective device. AFDDs are required to be located at the switchboard supplying the final subcircuit. The installation of AFDDs should be considered when carrying out alterations to final subcircuits in situations where existing wiring systems may significantly deteriorate.
However, in New Zealand all final subcircuits with ratings up to 20 A will require protection by an AFDD if they supply locations with significant fire risk, locations containing irreplaceable items, certain historic buildings, or socket-outlets in school dormitories.
Clause 3.3.2 now describes an additional external influence on wiring systems: thermal insulation. Clause 3.3.2.13 states that the rated current-carrying capacities of cables passing through bulk thermal insulation is to be calculated according to the length of cable passing through the insulation (in accordance with AS/NZS 3008.1).
Definition of stand-alone power system (SAPS): This concept has been redefined to accommodate renewable energy generation, i.e. photovoltaic arrays, wind turbines, and mini-hydro turbines.
Conditions for isolation: An inverter or regenerative supply source shall not be connected
downstream of the generating set changeover device. Exception: This requirement need not apply where control systems prevent backfeed to the generator.
Conditions for MEN connection: The neutral-earth connection (MEN connection) shall be made within the installation at the main switchboard. This may require disconnection of any neutral-earth connection within an electricity generation system, such as an engine-driven generating set.
A number of informative appendices have been included in the 2018 version of AS/NZS 3000, which provide useful information contained within other Australian Standards. As they are not classified as normative appendices, the information is provided to help the reader understand the intent of the standard. These are as follows:
This Appendix describes the selection of circuit protection and switching devices operated on a d.c. supply that would be deemed to meet the requirements of this Standard. Among other topics, it describes requirements for arc suppression, switchgear typing, d.c. ratings, subcircuit wiring/fittings, switchboard locations, and inverters.
The Electricity (Safety) Regulations 2010 cite AS/NZS 3000:2007 including its Amendments 1 and 2. This means the 2007 standard must be used to ensure compliance with the Regulations, until the Regulations are updated to cite the 2018 edition.
This expertise is what differentiates a professional licensed practitioner from an everyday person. As a licensed person you have been granted the right to carry out restricted work that others cannot do. These people are relying on your skills, and you in turn have an obligation to be competent with testing procedures.
For the scope of this answer we are looking at the minimum tests required on an installation as per AS/NZS 3000;2007. Competency in these basic tests would give you transferable testing skills across the more specialised High Risk areas of the industry. Competency in these basic tests will require the right test equipment, practice and knowledge.
This Standard provides requirements for the selection and installation of electrical equipment, and design and testing of electrical installations, especially with regard to the essential requirements for safety of persons and livestock from physical injury, fire or electric shock.
This Standard sets out requirements for the design, construction and verification of electrical installations, including the selection and installation of electrical equipment forming part of such electrical installations.
These requirements are intended to protect persons, livestock, and property from electric shock, fire and physical injury hazards that may arise from an electrical installation that is used with reasonable care and with due regard to the intended purpose of the electrical installation. In addition, guidance is provided so that the electrical installation will function correctly for the purpose intended.
AS/NZS 3000:2007 is cited by AS 4032.4:2014 Water supply - Valves for the control of heated water supply temperatures. Part 4: Thermostatically controlled taps for the control of heated water supply temperatures
AS/NZS 3000:2007 cites AS/NZS 3439.3:2002 Low-voltage switchgear and controlgear assemblies -Part 3: Particular requirements for low-voltage switchgear and controlgear assemblies intended to be installed in places where unskilled persons have access for their use - Distributio
AS/NZS 3000:2007 cites AS/NZS 3439.5:2001 Low-voltage switchgear and controlgear assemblies - Part 5: Particular requirements for assemblies intended to be installed outdoors in public places - Cable distribution cabinets (CDCs) for power distribution in networks
The maximum demand tables are based on Table C1 and Table C2 in AS/NZS 3000:2018. I added a few specific load groups to simplify the calculator. I have also re-phrased the text. However, the formulas and the calculated results. The tables below should be read in conjunction with the standard, which includes additional information, and examples.
Note that the current for the air conditioner is from the manufacturer's specification. It is not calculated from the cooling or heating kilowatt rating, because a reverse cycle air conditioner uses less electricity relative to the cooling or heating power.
The new version of AS/NZS 3000 Wiring Rules Standard (Electrical Installations) contains over 200 changes and expands coverage on electrical installations, improves safeguards, takes account of new technology and clarifies certain ambiguous requirements from the previous version.
All new (including alterations/renovations) domestic and residential installations, the final sub-circuits are to be RCD protected, with the exception of additional new work to existing lighting circuits. Air-conditioners, electric hot water systems, hotplates and ovens require a safety switch.
There are exceptions that can be applied where the equipment has leakage current that would impair reliable operation. A risk assessed appropriate alternative method of installation and equipment selection will be needed to achieve the same level as RCD protection. This could include additional mechanical protection, a separated supply or earth monitoring protection.
The existing requirements of the protection of electrical cables has been clarified and additional methods of installation will now be required. In areas where cables are not easily accessed in a roof space, electrical cables will need some form of fixing by clipping or tying.
Where, in a roof space, electrical cables can be stood on, a suitable form of covering is required to prevent the electrical cables from being damaged. Clauses 3.3.2.6 and 3.9.3.3.2 address these requirements. Appendix H provides additional guidance with examples.
Where cables are installed within walls and ceilings, a dispensation from additional mechanical protection has been withdrawn. An exclusion zone from requiring mechanical protection of 150mm from a ceiling or wall has been deleted. This will require additional work to add a suitable barrier or enclosure to protect cables that are not installed with RCD protection. These cables may include consumer mains, additional switchboard main supply cables and the like. Clause 3.9.4.2 addresses these requirements.
Clause 3.10.3.1 sets out requirements for roof top installations using a wiring enclosure to ensure the installation does not impede the ability of the roof to clear water by its initial design. This would apply to solar PV systems, hot water and air-conditioning installations and the like.
c01484d022