Tech Tips FAQs
Vertical Earth Stakes
Q: What are the requirements for vertical earth stakes (electrodes)?
A: An earth stake must be installed to a minimum depth, style, and size as per AS/NZS 3000:2018 Table 5.2.
Domestic and Non-Domestic Residential Installations
Q: In non-domestic and non-residential installations socket outlets, lighting, direct connected hand-held or direct connected electrical equipment 32 Amps and less need to be protected by an RCD?
A: Yes. However, there is an exception.
See Clause 126.96.36.199.3.3, Requirements for additional protection.
But before you think you don’t need an RCD, read on.
There is limited reason as to why the exception to this rule can be applied, especially if injury or death occur after negating the installation of an RCD. You could apply common sense, where for example; vehicle tunnel lighting that was mounted approximately 5 metres agl and was Class 2 constructed equipment including all cabling being double insulated in non-conductive conduit where the risk of light failure would be greater than the risk of electric shock. The risk being that in the event of the tunnel lighting failure, vehicles would have to transition rapidly from not having headlights on, to suddenly turning them on in pitch black conditions. Tunnel lighting requirements for lighting is always to remain on as per local road’s authority rules in conjunction with the minimum requirements of AS/NZS 1158 for the lighting of roadways.
Whilst this is not electric shock-related, the shock risk is negated by utilising double insulated light fittings and non-conductive conduit. In this case, there are two risks being minimised, traffic accident and electric shock. The other factors, in this case, would be that only authorised personnel are permitted to work in the tunnel, there was no public access, and everything was out of reach. You would also need to risk assess and record this, including appropriate warning labels with notification given to the client making sure that the client understood the ramifications.
Other cases such as VSDs, fixed cranes and 20A three-phase outlets for equipment would be extremely hard to apply the exception.
However, in Coronial Court, there will no argument that will support the defendant as to why they negated installing an RCD when there is a deceased person as a result of electrocution as an RCD is would have saved them.
My advice is, install RCDs for equipment in non-domestic and non-residential 32 amps and below, then you will be covered.
Installing multiple 20A 3 Phase Socket Outlets on one circuit
Q: Can I Install multiple 20A 3 phase socket outlets on one circuit?
A: Yes, however, this would not meet the criteria of Clauses 1.6.1 (e), 1.7.1 and 1.7.2.
The main issue is that to install multiple outlets on one circuit, the cable and RCD would have to be currently matched to the load required by the outlets say at 20A each. Accounting for voltage drop and installation conditions, this circuit would be expensive to install compared to individual circuits for each outlet. The clauses above relate to faults and the reliability of the circuit including safe and sound work practices and sound principles
So, would I install multiple 20A 3 phase socket outlets on a single circuit? No, it isn't best practice nor does it meet the requirements of the above clauses
Equipotential Bonding Conductor Connection Point
Q: Do I have to install an Equipotential Bonding Conductor Connection Point?
A: Yes. As stated in AS/NZS3000:2018 amendment 1 Clauses 188.8.131.52.2 and 184.108.40.206.3. The connection must be accessible, identifiable on the originating switchboard or other permanent locations, protected against corrosion and mechanical damage and designed and constructed in accordance with Clause 3.7.
Q: Do I have to bond a swimming pool and the pool fence?
A: Yes. A pool must be bonded. This has always been a rule. The current Wiring Rules AS/NZS 3000:2018 amendment 1 January 2020, clause 220.127.116.11 regarding Swimming and spa pools and the following clauses 18.104.22.168.1 to 22.214.171.124.3. And a picture is worth a thousand words so have a read of Figure 5.9 as well.
Basically, anything that is conductive within arm’s reach (1.25m) shall be bonded. However, there is an exception. Also, if you are trying to earth a glass pool fence, that being the supporting feet, suggest to the pool builder to use composite material instead of metal?
Installation of Smoke Detectors
Q: How many smoke detectors do I need to install and what location in a Class 1a building (single dwelling)?
A: Depending on which state or territory the minimum requirement as per the NCC clause 126.96.36.199 shall be one on each storey containing bedrooms between each part of the dwelling containing bedrooms and where bedrooms are served by a hallway and any other storey not containing bedrooms. In Queensland, the requirement is to install smoke detectors in each room used for sleeping including egress paths from these rooms and on each level of a house. In NSW, Tasmania and the ACT, the minimum requirement is one on each level and one located outside a bedroom or group of bedrooms. Photoelectric and ionisation type alarms are OK to use in ACT, TAS and NSW, but QLD must be the photoelectric type.
Always check the local fire authority website for guidance in your state or territory and the National Construction Code for the minimum requirements.
Service and Installation Rules NSW Interpretation
Recently NECA was approached by a member and their client regarding a loss of supply via an underground service main. This resulted in NECA collaborating with Ausgrid considering different opinions of the interpretation in the responsibility of maintenance and ownership of service mains. Whilst on this occasion Ausgrid replaced the service there is still more work to be done towards clarification of the Distributor’s responsibilities regarding underground and overhead service mains. NECA is advocating for successful outcomes for members and their customers including the distributors. NECA is working for stronger relationships with the three NSW Distributors and communicating together for clarity for everyone in NSW whilst considering the needs and expectations of industry, stakeholders and the public.