Why does my switchboard keep tripping? (Brisbane troubleshooting from a sparky)

If your switchboard's been tripping randomly, you've probably already done the dance: walk to the board, flip the switch back up, hope it stays. Usually it does. Sometimes it doesn't.

Before you reset it again, here's the diagnostic order I run through on every Brisbane switchboard call.

First, figure out what tripped

Open your switchboard cover. There are three kinds of switch you might be looking at:

• A circuit breaker, looks like a small switch labelled with an amp rating (16A, 20A, 32A) and a circuit name ("Power 1", "Lights", "Oven"). Trips up = on, down = off.
• A safety switch (RCD), looks similar but has a small button labelled "T" or "Test".
• A main switch, usually the biggest switch, often labelled "Main". If this one trips, the whole house goes off.

Identify which one is in the "off" position. That tells you what kind of fault you're dealing with.

If it's a safety switch (RCD)

Safety switches trip when they detect current leaking to earth, i.e. through something it shouldn't (a faulty appliance, water, a damaged cable). They are doing their job. Don't just keep resetting them.

Diagnostic procedure:

1. Unplug every appliance on that circuit.
2. Reset the RCD. Did it stay on? Yes → an appliance is faulty. No → the wiring on that circuit has a fault.
3. Plug appliances back in one at a time. The one that re-trips the RCD is your faulty appliance.

If the RCD won't even stay on with everything unplugged, stop resetting it, the fault is in your wiring, not an appliance. Ring an electrician.

If it's a circuit breaker

Circuit breakers trip on overload, too many amps. The classic Brisbane case: kettle + microwave + heater on the same circuit in winter. The fix:

1. Unplug everything on the circuit.
2. Reset the breaker.
3. Plug things back in one at a time, with the smaller stuff first.
4. Note which appliance pushes it over the edge.

Long-term fix: split the load across more circuits. That's a switchboard upgrade job.

If the breaker trips with nothing plugged in, that's a short circuit somewhere in the wiring. Stop and call.

If it's the main switch

The main switch should never trip on its own. If it has, one of two things has happened:

1. A massive earth-leakage fault somewhere downstream, usually a flooded outlet, water in a fitting, or a heavily damaged cable.
2. A serious overload that exceeded the rating of the entire main switch (rare in domestic).

Either of those is a stop-and-call situation. Don't reset the main switch repeatedly.

When to stop and call

Stop resetting and ring 0411 054 811 if:

• A breaker trips immediately the moment you reset it, even with nothing plugged in
• An RCD won't stay on with all appliances unplugged
• You can smell burning from the switchboard
• The board is warm to touch
• The main switch has tripped
• It's been raining and parts of the house won't come back on

We do same-day make-safes anywhere in our core service area and most are diagnosed and fixed inside an hour. The cause is usually one of three things, a dying old appliance, a loose terminal in the board, or rodent damage in the roof, and all three are easier to find when the sparky has the right test gear.

, John