Why does my RCD (safety switch) keep tripping?
An RCD trips when current leaks to earth. How to isolate the cause safely, and when it becomes a licensed electrician job.
Quick answer
An RCD (safety switch) trips when it detects current leaking to earth -- usually a faulty appliance, moisture in a circuit, or a damaged cable. Unplug everything on the affected circuit and reset; if it holds, plug items back one at a time to find the culprit. If it trips with nothing plugged in, the wiring itself needs a licensed electrician. Never bypass or tape an RCD closed.
- Skill level
- All levels
- Time
- 4 min read
- Trade
- Electrical
- Updated
- 14 November 2026
The short answer
A tripping RCD is doing its job: it cuts power in milliseconds when it senses current escaping to earth, which is what protects you from a fatal shock. The trip is a symptom, not the fault -- something is leaking, and the switch is telling you before it hurts someone.
The fastest way to isolate it: turn off every appliance on the dead circuit, reset the RCD, then switch appliances back on one at a time. The one that trips it again is your leak. A common culprit is a kettle, iron, fridge, or outdoor lead that has taken on moisture.
What it depends on
Your next step
If the RCD holds once a suspect appliance is unplugged, you have found your fault -- repair or replace that appliance. If it keeps tripping with everything off, or trips instantly the moment you reset it, stop there: that is a wiring fault, and in Australia electrical wiring must be worked on by a licensed electrician. It helps to understand your board first -- see understanding your switchboard -- and browse more electrical guides.
Frequently asked questions
- Is it safe to keep resetting a tripping RCD?
- Resetting once to test is fine. But if it keeps tripping, stop -- the switch is detecting a real earth leak. Repeatedly forcing it back on defeats the protection that stops you being electrocuted.
- Can I fix a tripping safety switch myself?
- You can isolate a faulty appliance by unplugging things one at a time. You cannot legally or safely work on the wiring or the switchboard -- that must be a licensed electrician in every Australian state and territory.
- Why does my RCD only trip when it rains?
- Moisture getting into outdoor power points, garden lighting, or a damaged external cable lets current leak to earth. It often resets once things dry out, but a circuit that trips every time it rains has a fault worth having checked.
Written by Sparky, the Electrical specialist at WA.Tools.