A breaker trips to protect your home, usually because of an overloaded circuit, a faulty appliance, a leak of current to earth, moisture or a damaged connection. One trip is often harmless. Repeated or unexplained trips, or any heat, smell or noise, are reasons to call a licensed electrician.
A tripping breaker is annoying, especially when it takes out the fridge or the internet. It is also your switchboard doing exactly what it was designed to do. The useful question is not "how do I stop it tripping" but "what is it trying to tell me?"
Here is what is going on and when it is time to get a professional involved.
Two different devices, two different jobs
Most Dunedin homes have more than one kind of protective device in the switchboard, and they trip for different reasons.
- Circuit breakers protect each circuit from overload and short circuits. They trip when too much current flows.
- Residual current devices (RCDs), often called safety switches, constantly compare the current going out and coming back. If some of it is leaking to earth, such as through a person or a faulty appliance, they switch off very quickly. WorkSafe describes them as designed to protect against the risks of electrocution and fire caused by earth faults.
Knowing which one tripped is useful information for your electrician, because the likely causes differ.
Common causes of tripping
Too much load on one circuit
Heaters, kettles, toasters, hairdryers and heat appliances all draw a lot of power. Run several at once on the same circuit and the total can exceed what it is designed to carry. That is an overload and a breaker is meant to trip.
If tripping only happens when a particular combination of appliances is running, overload is a reasonable suspect. But if the same circuit is regularly struggling with ordinary use, it is worth asking an electrician whether the circuit suits how you live now. Do not swap a breaker for a bigger one to make the problem go away. The breaker is sized to suit the wiring on that circuit.
A faulty appliance or cord
An appliance with a fault inside, or a damaged cord, can cause a trip as soon as it is switched on or plugged in. A common pattern is that the trip happens every time the same item is used. Stop using that item and do not keep plugging it back in.
Moisture
Damp in a power point, outdoor fitting or light, or an appliance that has got wet, can allow current to leak. Trips that follow rain, a wash-down, or a leak are worth mentioning to an electrician. WorkSafe's advice after flooding or water damage is to turn the power off at the mains and have an electrician check the installation before it is used again.
Damaged or loose connections
Wiring that has been damaged, or a connection that has worked loose over time, can cause intermittent trips, flickering or heat. This is not something to look for yourself. A switchboard and the wiring behind it should only be worked on by a licensed electrician.
An ageing protective device
Like anything, breakers and RCDs can wear. An RCD that trips for no clear reason, or that fails its test, may need to be assessed. WorkSafe says to seek advice from a licensed electrical worker if an RCD test button does not work as expected.
Nuisance tripping
Sometimes there is no single fault, but several small leaks of current across a circuit add up and trip an RCD. An electrician can test circuits and appliances to find out what is happening, which is far more reliable than guesswork.
When it is time to call an electrician
A trip on its own does not mean something is badly wrong. It is worth booking an electrician if:
- The same breaker or safety switch trips repeatedly.
- It trips and you cannot link it to any appliance or activity.
- A breaker or safety switch will not reset or stay on.
- You notice a burning smell, scorch marks, a warm switchboard or buzzing sounds. In that case turn off the main switch and call. WorkSafe's advice is to isolate the power and contact a registered electrical worker.
- Trips follow rain, flooding or a leak.
- You have added new equipment, such as a heater or a charger, and the trips started afterwards.
What you can sensibly do
Without opening or touching anything inside the switchboard, you can help an electrician get to the bottom of it quickly by noting:
- Which switch tripped, if the switchboard is labelled.
- What was running or being used at the time.
- How often it happens and whether the weather or time of day seems to matter.
- When it started.
If it is clearly one appliance, stop using it. Otherwise, avoid repeatedly resetting a breaker as a workaround.
What an electrician will do
A licensed electrician will test the circuit and the protective devices, check connections and, where needed, isolate which appliance or wiring section is involved. If testing points to a worn protective device or an ageing board, a switchboard upgrade may be one of the options. They can explain the cause, whether any work is needed and what it involves. If new fixed wiring is installed, you should receive a Certificate of Compliance.
If a breaker or safety switch at your place keeps tripping, talk to Honest Electrical. We will find the cause and tell you plainly what it needs.