The short answer
In NSW, safety switches (RCDs) are required when electrical work is done, not simply because a home exists. Under AS/NZS 3000:2018, the Wiring Rules, new domestic installations need 30 mA RCD protection on every final subcircuit. If an existing circuit is altered or a new one is added, that circuit must get RCD protection. If a switchboard is replaced for any reason, every applicable circuit on it must be protected. We have not found any general NSW law that makes owner-occupiers or landlords retrofit safety switches to an existing home that isn't being worked on, although a faulty one in a rental is an urgent repair. Workplaces have their own rules under the WHS Regulation.
The rules for homes
New homes and new installations
Clause 2.6.3.2.2 of AS/NZS 3000:2018 requires 30 mA RCD additional protection on all final subcircuits in domestic and residential installations, with the RCDs at the switchboard where each subcircuit starts. NSW has applied AS/NZS 3000:2018 since 1 January 2019.
In practice, a home needs at least two RCDs, with no more than three final subcircuits on any one RCD, and lighting circuits split across RCDs. We simply fit an RCBO on every circuit instead. See RCD vs RCBO for why.
Adding or altering a circuit
The Electrical Regulatory Authorities Council (ERAC) issued an advisory note, endorsed by all Australian regulators, on how the RCD rule applies to existing homes (clause 2.6.3.2.5):
- If you alter one final subcircuit, only that circuit must get an RCD or RCBO. The rest of the house doesn't have to be upgraded.
- RCDs protecting added power points, lights or equipment in an existing home must be installed at the origin of the circuit, which is the switchboard. A plug-in or power point safety switch doesn't satisfy this.
- Replacing a power point, light or single item of equipment with an equivalent in exactly the same place, without altering the circuit, is treated as a repair, so no RCD is required. That includes swapping a single power point for a double.
So adding one power point in the lounge doesn't mean the whole house needs safety switches. It means the circuit you added to does.
Replacing a switchboard
If the switchboard is replaced for any reason, every applicable final subcircuit from that board must have RCD protection. That is why a switchboard upgrade always includes safety switches on every circuit.
The type of RCD
Since 1 May 2023, Type AC RCDs may not be installed in new electrical work in NSW, and they can no longer be sold here. Type A is the standard for household circuits. Building Commission NSW notes Type B for circuits with higher DC leakage risk, such as EV chargers and solar inverters. Specific NSW advisory notes also require Type A on new or upgraded heat pump hot water circuits, and RCD protection (Type A, not Type AC) on circuits supplied by a home battery's backup supply.
Existing homes: is there a retrofit law?
We have not found any general NSW law that requires owner-occupiers to add safety switches to an existing home that isn't having work done. Some other states have their own rules for homes being sold or rented, but those don't apply in NSW.
That said, there is good reason to have them. SafeWork NSW says RCDs protect against electric shock and give some protection against electrical fires, and the NSW Government says electrical faults and appliances cause 40% of NSW house fires each year. If your board has no "T" or "Test" buttons, it is worth a conversation.
Rental properties
NSW rentals are not required by law to have a safety switch installed, based on the NSW Government's rental pages. What the rules do require:
- The start-of-tenancy condition report must record whether a safety switch is present and whether it works.
- Any electrical fault is an urgent repair, and that includes a faulty safety switch or one that keeps detecting a fault.
- Landlords must have urgent repairs done within a reasonable time, using a licensed electrician.
More on this in landlord electrical obligations in NSW.
Workplaces, sheds and farms
Workplaces are covered by the NSW Work Health and Safety Regulation 2025, which replaced the 2017 Regulation on 22 August 2025. Under section 164, plug-in equipment needs RCD protection where it is:
- used in conditions likely to damage it, such as moisture, heat, vibration, mechanical damage, corrosive chemicals or dust;
- moved between places where damage is likely;
- moved frequently in normal use; or
- part of an amusement device.
That covers a lot of Riverina workplaces: farm workshops, shearing sheds, irrigation pump sites, building sites and trade vans. The person with management or control must also make sure RCDs are tested regularly by a competent person, and keep records of tests (other than push-button tests) until the next test or until the device is disposed of. See how to test a safety switch.
Testing your safety switches at home
The NSW Government advises householders to press the "T" or "Test" button on each safety switch about every six months. That is a recommendation, not a legal requirement for homes. If the power doesn't cut off, or the switch won't reset, call a licensed electrician.
Who can install a safety switch?
Only a licensed electrician. Installing an RCD is electrical wiring work, and in NSW you need a licence for any of it, whatever the size of the job. The work must be tested and certified with a Certificate of Compliance for Electrical Work (CCEW), lodged through the Building Commission NSW eCert portal within seven days of the test.
Common questions
Is it law to have a safety switch in NSW?
Not for every existing home. Safety switches are required on new installations, on circuits that are altered or added, and on all circuits when a switchboard is replaced. We have not found a general NSW retrofit law for existing homes.
Do landlords have to install safety switches in NSW?
We have not found a NSW law requiring it. The condition report must record whether one is present and working, and a faulty safety switch is an urgent repair the landlord must fix.
If I add a power point, do I need safety switches on the whole house?
No. Under the ERAC advisory note, only the circuit you alter or add to needs RCD protection. The whole board needs it only if the switchboard is replaced.
Are Type AC safety switches illegal in NSW?
They can't be installed in new electrical work since 1 May 2023 and can no longer be sold in NSW. New work uses Type A, or Type B where the circuit needs it.
How often should safety switches be tested?
At home, the NSW Government recommends pressing the test button about every six months. In workplaces, RCDs must be tested regularly by a competent person, with the interval set by the type of workplace and its risks.