A safety switch, also called a residual current device or RCD, cuts the power in a fraction of a second if it detects electricity leaking to earth, which is exactly what happens when current passes through a person. It is the device most likely to save a life in your home. Electrical Powerhaus installs, tests and replaces safety switches across Melbourne, and we can add protection to every circuit in your home in a single visit.
How a safety switch works
Electricity should flow out along the active wire and back along the neutral in equal amounts. A safety switch constantly compares the two. If some of the current goes missing, it has found another path to earth, through a faulty appliance, damaged cable or a person. When the difference reaches about 30 milliamps the switch trips, usually well within the 300 millisecond limit set by the standard. That is fast enough to stop a shock from becoming fatal in most cases.
A circuit breaker cannot do this. Breakers only react to too much current, which protects the wiring from overheating but does nothing for someone touching a live part. That is why modern switchboards have both, and why many electricians now use combined devices called RCBOs that give each circuit its own protection.
Does your home have enough protection?
Many Melbourne homes have some protection, but not enough. Common gaps we find:
- One safety switch covering only the power points, with lights unprotected
- Several circuits sharing one switch, so a fault in the garage cuts power to the fridge
- Old switches that no longer trip when the test button is pressed
- Outdoor power, pools, spas and sheds with no protection at all
- Granny flats and outbuildings fed from the house without their own safety switch
Current Australian wiring rules require safety switch protection on all final circuits supplying power points and lighting in new homes, and on any new or altered circuits in existing homes. If your home predates those rules, adding protection is one of the most worthwhile electrical jobs you can do.
Testing your safety switch
Energy Safe Victoria recommends pressing the test button on each safety switch every three months. The switch should snap off straight away. If it does not trip, or trips only after a delay, it is not protecting you and needs replacing. We cover the full process in our step by step guide to testing an RCD. For businesses, safety switches also need regular trip time testing with proper equipment, which we can do and record for you.
Why does my safety switch keep tripping?
A safety switch that trips is usually doing its job. Something on that circuit is leaking current. The most common culprits are a faulty appliance, water in an outdoor power point or garden light, a failing element in a hot water system or oven, or damaged cable. Unplug everything on the circuit, reset the switch and plug items back in one at a time. If it trips with nothing plugged in, leave it off and call us. Never tape a safety switch in the on position or ask someone to bypass it.
What does safety switch installation cost?
The cost of adding safety switches depends on how many circuits need protection, whether your switchboard has room for new devices and whether the board itself is in good enough condition to keep. Adding protection to a modern board with spare space is a quick job. Adding it to an old fuse board usually means a switchboard upgrade instead, which gives you protection on every circuit at once. We look at your board, explain the options and put a fixed price in writing before any work starts. There is no call-out fee, and your first service with us is 15% off. Our Melbourne electrical cost guide shows typical ranges.
How long does it take?
Adding safety switches to a board with spare room usually takes an hour or two. Replacing a faulty switch is often quicker. If the work turns into a full switchboard upgrade, allow most of a day. Every job finishes with testing each switch for trip time and current, and we lodge a Certificate of Electrical Safety for the work.
Safety switches for landlords and businesses
Victorian rental properties need an electrical safety check every two years, and missing or faulty safety switches are among the most common issues we find. Businesses have extra obligations to test protective devices regularly and keep records. We handle both, and our electrical safety and compliance service covers the full inspection and written report.
We install safety switches right across Melbourne, from the inner suburbs to the bayside and the outer east. Find your suburb on our service areas page.
Frequently asked questions
What is the difference between a safety switch and a circuit breaker?
A circuit breaker protects the wiring from overload and short circuits. A safety switch protects people by cutting power when it detects current leaking to earth. You need both.
How often should I test my safety switch?
Press the test button every three months. It should switch off instantly. If it does not, call a licensed electrician to replace it.
Is it legal for me to replace a safety switch myself?
No. In Victoria all electrical work, including replacing a safety switch, must be done by a licensed electrician and certified.
Do I need a safety switch on every circuit?
New work must have safety switch protection on power point and lighting circuits. For an existing home it is strongly recommended, because unprotected circuits are where serious shocks happen.
What is an RCBO?
An RCBO combines a circuit breaker and a safety switch in one device, so each circuit has its own protection and a fault on one circuit does not turn off the others.
Want every circuit protected? Call 03 6358 2028 for a fixed written quote. $0 call-out, and 15% off your first service. After hours emergencies: 0432 220 069.
Real work from the Powerhaus crew
Every photo is one of our jobs, taken by our team.
