Electrical installationESV has compiled a list FAQs on electrical installation. If your query is not addressed below, please contact us.
What required tests must a licensed electrical worker carry out to verify that their electrical work complies, and is safe to be connected to an electricity supply?
Testing and an inspection must be carried out to the requirements of section 8 of AS/NZS 3000 (The Wiring Rules) to verify that the electrical work complies.
The electrical worker must carry out the following tests along with a visual inspection of the electrical work.
- Continuity of the earthing system e. earth resistance of the main earthing conductor, protective earthing conductors and bonding conductors.
- Insulation resistance of the wiring system.
- Polarity of the consumer’s mains and the wiring system.
- Correct circuit connections.
- Verification of impedance required for automatic disconnection of supply e. earth fault-loop impedance.
- Operation of RCDs.
AS/NZS 3017 Electrical Installations – Testing and inspection guidance sets out some common inspection and test methods.
In patient areas such as a doctor’s clinic or dental practice, is it the licensed electrical worker’s responsibility to ensure that the installation of the new socket-outlets complies with AS/NZS 3003?
If the licensed electrical worker knows or should reasonably be expected to know the area is a patient area or intended to be a patient area, the electrical worker must ensure the installed, altered, repaired or maintained portion of the installation complies with AS/NZS 3003 Electrical installations—Patient areas.
Any person who engages an electrician to work on any premises that contains a patient area or an area that is intended to be a patient area, must ensure the electrician is given written notice prior to the carrying out of work that includes the location and boundary of any patient area.
The work will be prescribed electrical work and will need to be inspected by an M-class, licensed electrical inspector (LEI). The work must also be tested in accordance with AS/NZS 3000 to verify it complies with AS/NZS 3003 once the work is completed, and before certification and inspection.
What type of electrical work can an apprentice electrician do, and what level of supervision must be provided?
It is now a requirement under the Electricity Safety (General) Regulations 2019 that any person who employs an apprentice must ensure the apprentice is given effective supervision in accordance with ESV’s published Apprentice Supervision Requirements. This requirement extends to any licensed electrician or licensed electrical switchgear worker who has been tasked with supervising an apprentice who is carrying out electrical installation work.
When carrying out insulation resistance (IR) testing of underground consumer's mains, should the insulation resistance should be greater than 50 megohms?
Before the underground consumer’s mains are first placed into service or used, the insulation resistance between: conductor to each conductor; each conductor to earth; and each conductor to any metallic sheath or enclosure, must be tested with a 500V d.c. IR tester, and the IR must not be less than 50 megohms (for consumer’s mains up to 50m in length).
Table 228 of the Electricity Safety (General) Regulations 2019 provides lower insulation resistance for underground consumer’s mains longer than 50m.
When installing a battery system that is associated with a solar system, is it prescribed electrical work that needs to be inspected by a licenced electrical inspector? If so, what standards need to be followed?
Any battery energy storage systems and their associated battery systems, as defined in AS/NZS 5139, must be installed to comply with this standard. This standard applies to battery systems that normally operate between 12V d.c. and 1,500V d.c., and are connected to one or more inverters.
All electrical work on a battery energy storage systems, with the exception of repairing or replacing a single component part, is prescribed electrical work and must be inspected by a licenced electrical inspector.
All other secondary battery systems, as defined in the scope of AS3011, installed in buildings, structures or premises such as those with critical power continuity requirements (e.g. Telecom, UPS, hospitals, sub-stations and black start) outside the scope of AS/NZS 5139, shall comply with AS/NZS 3000 and AS 3011.
When installing an electric cooktop, does an induction cooktop require a switch above the bench on the splashback?
All cooking appliances with an open electric cooking surface must be provided with a switch that is mounted near the appliance in a visible and readily accessible position. The switch must be capable of turning off the appliance.
The switch should be mounted within 2m of the cooking appliance. The switch must not be mounted on the cooking appliance itself.
The switch or any other switches or power-outlets must not be located on any wall, cupboard or other surfaces within 150mm of the edge of an open cooking surface (gas or electric).
What needs to be done and what description should be put on the certificate of electrical safety for an electrical installation that has been disconnected from supply for more than 12 months?
It is the policy of the Electrical Distribution Business to have a property inspected if it has been disconnected from supply for more than 12 months. This is to ensure that a property is safe to have the power reconnected. This policy is endorsed by ESV.
A licensed electrician will need to be satisfied that the property is safe to have the power reconnected. This could be done by a combination of visual inspection and testing. Reference should be taken from Part 8 of AS/NZS3000 on inspection and testing requirements.
The description on the COES should reflect that the electrician has carried out an inspection and testing, and that the electrical installation is safe to reconnect to the electricity supply.
How long has an electrician got to have prescribed electrical installation work inspected by a licensed electrical inspector?
The electrician has eight business days after the work is completed to have that work inspected by a licensed electrical inspector (LEI).
Prescribed electrical installation work must be inspected by an LEI before the electrical installation, or that portion of the electrical installation, is connected to the electricity supply.
If an electrician replaces a main switchboard at a property, power cannot go back onto the new main switchboard until the work has been inspected by the LEI.
Where a property has more than one electricity supply, any new electrical work must strictly comply with the requirements of regulation 218 of the Electricity Safety (General) Regulations 2019 – Properties with multiple points of supply.
This is summarised as:
- Zones must be established within the property;
- Each zone established must, wherever possible, follow easily recognisable property features;
- Zones must not intermingle with or cross over other established zones;
- Each incoming supply must only supply electricity within one zone;
- A zone diagram must be placed in each main switchboard within the property;
- The zone diagrams must contain the following information;
- A diagram showing the location and boundaries of each zone;
- The location of each zone’s point of supply and consumer’s mains;
- The location of each zone’s main switchboard;
- The location of any sub mains or switchboards located within any zone;
- Each main switchboard at the property must be clearly and permanently marked with the following words “Warning—not all wiring installed in these premises is controlled from this main switchboard”; and
- Each switchboard that is not a main switchboard must be clearly and permanently marked with a label that clearly identifies the main switchboard it is connected to.