Why your safety switch keeps tripping

First, work out whether it is actually the safety switch

Open the switchboard and look at what has moved. A safety switch has a small TEST button on it. A circuit breaker does not. If the thing that tripped has a test button, you have an earth leakage fault. If it does not, you have an overload or a short, which is a different page.

The test that narrows it down in five minutes

1. Turn every circuit breaker off, one by one.
2. Reset the safety switch. It should hold, because nothing is connected.
3. Turn the breakers back on one at a time, waiting a few seconds between each.
4. The one that trips it is the circuit with the fault.

That tells you which circuit. It does not tell you what on that circuit is faulty, and finding that is the part you need a licensed electrician and test instruments for.

What it usually turns out to be up here

Across 8,840 fault finding jobs since 2020, the same handful of causes come up again and again in this climate.

• A failing hot water element. The classic sign is a trip overnight or in the early hours, because that is when an off-peak system heats. If it trips at 2am and holds all day, look at the hot water first.
• Moisture in an outdoor power point or garden light after heavy rain. Very common through the wet.
• Pool and spa equipment. Pump motors take in moisture and the windings go. Pool lights do the same.
• Ants and geckos in outdoor enclosures. Not a joke. It is genuinely one of the most common causes we find in the Douglas Shire, and it is why a fitting that has been fine for years suddenly is not.
• An old appliance. Kettles, toasters and washing machines all fail to earth eventually.
• Perished wiring in the ceiling of an older Queenslander, particularly where a roof has leaked.

What not to do

Do not keep resetting it. A safety switch is not being fussy. It has measured current going somewhere it should not, which in the worst case is through a person. If it will not stay in, leave that circuit off and ring someone.

Do not go looking in the roof space. Queensland restricts work and entry in domestic roof spaces where the electrical installation is not de-energised, and a hot ceiling in the wet season is a genuinely dangerous place.

The legal bit, briefly

If you have recently bought the place or started a new tenancy, Queensland gives you 90 days to have approved safety switches installed on the general purpose socket-outlet circuits. And in a rental, all power point circuits must have a safety switch attached. Worth knowing while someone is already at your board.

Sources: Electrical Safety Office, RTA Queensland and WorkSafe Queensland, 2024 amendment regulation.