In short: a safety switch that keeps tripping is almost always one faulty appliance, moisture in a power point, or a wiring fault. Unplug everything on that circuit, reset the switch, and plug things back in one at a time. If it trips with nothing plugged in, or the whole house is going off, stop and call an electrician.
Your safety switch keeps tripping and you're standing at the switchboard with a torch, flicking it back on for the third time tonight. It's one of the most common calls we get across Perth, and most of the time you can narrow down the cause yourself before anyone comes out.
What a safety switch actually does
A safety switch (also called an RCD, short for residual current device) watches the electricity going out on a circuit and coming back. If some of it goes missing, which happens when current leaks through a person or a fault to earth, it cuts the power in a fraction of a second.
So when it trips, it's doing its job. Something on that circuit is leaking current. The question is what.
A circuit breaker is different. It trips on overload, when you've got too much running at once. If the switch that keeps going has a test button on it, it's the safety switch. If it doesn't, it's a breaker, and the cause is usually an overloaded circuit rather than a fault.
The 5-minute test to find the cause
Do this before you call anyone:
- Unplug every appliance on the circuit that's tripping. Not switched off at the wall, actually unplugged.
- Reset the safety switch.
- If it stays on, plug appliances back in one at a time, and wait a minute between each.
- When it trips again, you've found your culprit.
If it trips straight away with nothing plugged in, skip to the section on wiring faults below.
The appliances that trip safety switches most
In Perth homes, these are the usual suspects:
- Fridges and freezers, especially older ones, where moisture gets into the compressor wiring.
- Kettles, toasters and irons with heating elements that have cracked and let moisture in.
- Washing machines and dishwashers, because water and electricity live close together.
- Hot water systems with a failing element. The element is on its own circuit, so if that's the one tripping, this is the likely cause.
- Pool pumps and outdoor equipment after rain.
- Anything with a damaged cord.
A fault that only shows up in wet weather is usually moisture. A fault that shows up when an appliance has been running for a while is usually a heating element.
When it isn't an appliance
If the safety switch trips with everything unplugged, the fault is in the wiring or the fittings, not what's plugged into them. The common ones we find:
- Water in an outdoor power point or light fitting after rain, particularly on older homes in the coastal suburbs where salt air corrodes fittings faster.
- Rodent damage to cables in the roof space.
- A damaged cable behind a wall from a picture hook or a renovation.
- A tired safety switch. They wear out, and one that trips randomly with no pattern is sometimes just at the end of its life.
- Too many circuits on one safety switch. Older boards often have one RCD covering the whole house, so a small leak from several appliances adds up and trips it. This is one of the reasons a Switchboard Upgrade Perth fixes nuisance tripping.
When to stop and call an electrician
Call straight away, don't keep resetting, if:
- It trips immediately with nothing plugged in.
- You smell burning or see scorch marks at the switchboard or a power point.
- The whole house is losing power, not just one circuit.
- It's tripping several times a day and you can't find an appliance causing it.
- You have a ceramic fuse board and aren't sure you even have a safety switch.
Repeatedly resetting a safety switch that's finding a real fault is how a small problem becomes a fire. Our Emergency Electrician Perth team responds same day, and every booked job includes a free switchboard inspection, so you'll know whether the switch itself is the problem.
Related reading
- RCD Rules in WA: How Many Safety Switches You Need Before You Sell or Rent
- When Should You Upgrade Your Switchboard in Perth?
Nexus Electrical Co | Emergency Electrician Perth
Nexus Electrical Co is a licensed electrician Perth homeowners have trusted for 6000+ jobs, based in Balcatta and covering the northern and coastal suburbs. Licensed and insured (EC14149), fixed price before we start, 100+ Google 5-star reviews. Call (08) 9245 1362 for a same-day response.
