Safety switch vs circuit breaker: what's the difference?
How safety switches (RCDs) and circuit breakers protect an Australian home, why they trip, how to test them and when to call an electrician.
Key takeaways
- A safety switch protects people; a circuit breaker protects wiring.
- Test safety switches regularly using the test button.
- A switch that trips again immediately needs a licensed electrician.
What a safety switch does
A safety switch — a residual current device or RCD — monitors current flowing through a circuit. If some of it leaks to earth, which can happen when current passes through a person, it cuts power in a fraction of a second. Safety switches save lives and are required on new and renovated circuits across Australia.
What a circuit breaker does
A circuit breaker protects the wiring from overload and short circuits. It trips when a circuit draws more current than it is designed for — for example, too many heaters on one circuit — or when there is a fault. It does not protect against electric shock the way a safety switch does.
How to tell them apart
Look at your switchboard. Safety switches usually have a test button marked "T" or "Test". Some devices, called RCBOs, combine both functions. If your switchboard still has ceramic fuses, ask a licensed electrician about upgrading.
Test regularly
Press the test button on each safety switch — many electrical regulators suggest every three months. It should trip immediately. Switch it back on. If it does not trip, book an electrician.
When tripping means a fault
Occasional trips are often caused by a faulty appliance. Repeated trips, trips with everything unplugged, burning smells or hot switchboards need a licensed electrician. Never tape a switch on or replace a device yourself.
General information only, reviewed for Australian conditions. Rules differ between states and territories and change over time, so confirm details with the relevant regulator. Call 000 in an emergency. Editorial policy
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