Why Does My Safety Switch Keep Tripping?

What This Article Covers

A quick overview before you dive in:

• What a safety switch (RCD) does, and how it differs from a circuit breaker, so you know which one has tripped.
• The common reasons a safety switch keeps tripping, from a faulty appliance or water getting in to a fault in the wiring.
• The safe steps you can take to find a faulty appliance, and the point where you should stop and leave it off.
• When a tripping safety switch is an emergency, when to call triple zero (000) first, and what an electrician does to find the cause.
• How to test your safety switches every six months, and what professional testing and an after-hours call-out cost.

If your safety switch keeps tripping, it has usually found a fault: most often a faulty appliance, sometimes water getting into something electrical, and sometimes a problem in the wiring. A safety switch that trips is doing its job, so the fix is to find the cause, not to keep forcing it back on.

This guide comes from Impulse Electrical Enterprise, a Sydney electrician based in Strathfield. We're licensed and insured, and our director, Matthew Neil, supervises every job. The steps below are the ones that are safe to try yourself. If they don't solve it, the next step is a licensed electrician.

What a Safety Switch Does

A safety switch, or residual current device (RCD), watches the electricity flowing in and out of a circuit. If some of it leaks away, for example through a faulty appliance, damaged wiring or a person, it cuts the power within milliseconds. The Queensland Electrical Safety Office explains that safety switches protect people, while circuit breakers and fuses protect the wiring from overheating.

That difference helps you work out what's happening. On your switchboard, safety switches usually have a test button marked T or Test. If a circuit breaker without a test button is the one tripping, the circuit may be overloaded or have a short circuit rather than a leak. Some safety switches are combined with a circuit breaker in one device, so they can trip for either reason. Either way, the steps below are the same.

Common Reasons a Safety Switch Keeps Tripping

• A faulty appliance. The most common cause. Kettles, toasters, heaters, washing machines, fridges and anything with a heating element or motor can develop a fault as they age.
• Water getting in. Rain or a leak can get into an outdoor power point, an outdoor light, a pool pump or a ceiling light under a leaking roof.
• Damaged wiring. Rodents chewing cables in the roof, a nail or screw through a cable, or old wiring breaking down can all cause a leak to earth.
• A faulty power point or light fitting. A burnt or damaged power point or fitting can leak current.
• A worn or faulty safety switch. Less often, the safety switch itself is at fault.

What You Can Safely Try

Only try this if the switchboard is dry and undamaged, and there's no burning smell, sparking or heat anywhere. If there is, leave everything off and call an electrician. If someone has had an electric shock, or there's a fire or smoke, call triple zero (000) first. Anyone who has had an electric shock should also see a doctor, even if they seem fine.

1. Switch off and unplug every appliance that lost power when the safety switch tripped.
2. Reset the safety switch at the switchboard.
3. Plug the appliances back in and switch them on one at a time. If the safety switch trips again, the last appliance you plugged in is likely the faulty one. Stop using it and have it checked or replaced.

If the safety switch trips straight away with everything unplugged, or won't reset at all, the fault is likely in the wiring, a power point or a fixed appliance such as an oven, hot water system or air conditioner. Leave it off and call a licensed electrician. Don't open the switchboard or a power point to look for it.

When a Tripping Safety Switch Is an Emergency

If it trips again as soon as you reset it and you've lost power to something you need, such as the fridge, or you can smell burning, call an emergency electrician. Our phones are answered 24/7, including public holidays. We confirm the call-out price on the phone before we send anyone: after hours it's $250 + GST. If it tripped once and has stayed on since, it's less urgent, but book a check so the cause is found.

If the power is out to your whole home rather than one circuit, our guide to what to do when the power is out at your house but not your neighbours' will help.

How an Electrician Finds the Fault

An electrician tests the circuit and the fixed appliances on it to find where the current is leaking, then repairs or replaces the faulty part once you've approved the price. We also check the safety switch itself. Our safety switch testing is $99 + GST per safety switch, with a written report, and we can add safety switches to circuits that don't have one.

On older switchboards, especially old fuse boxes, the answer is sometimes a switchboard upgrade with modern safety switches. We'll tell you if that applies and give you a fixed price before any work starts.

Keep Your Safety Switches Working

The NSW Government advises testing each safety switch at least every six months by pressing its test button. Let everyone at home know first. The power to that circuit should go off, and you can then switch it back on. If it doesn't go off, have it checked.

Questions About a Safety Switch That Keeps Tripping

Can a safety switch trip for no reason?

Not usually. It trips because it has detected current leaking somewhere. The fault can be intermittent, such as an appliance that only leaks when it heats up or a fitting that only leaks when it's wet, which can make it seem random.

Can rain make my safety switch trip?

Yes. Water getting into an outdoor power point, light or appliance can cause a leak to earth. If it trips during or after rain, keep away from wet fittings and call an electrician.

Is it dangerous if my safety switch keeps tripping?

It can be. The safety switch is protecting you, but the fault it has found can cause a shock or a fire, so don't keep forcing it back on. If the steps above don't find a faulty appliance, leave it off and have an electrician find the cause, especially if there's a burning smell, heat or sparking.

How much does it cost to fix a tripping safety switch?

It depends on the cause. We confirm prices before we start: safety switch testing is $99 + GST per switch, and an after-hours emergency call-out is $250 + GST. Any repair is quoted for you to approve first.

Safety Switch Still Tripping?

Tell us what's happening and what you've already tried. Call us on 0481 228 836, any time, or request a free quote if it can wait.