A Residual Current Device (RCD) is designed to protect you from electrical hazards by constantly monitoring the flow of electricity. The moment it detects something unusual, like electricity leaking where it shouldn’t, it shuts everything down in an instant. This prevents electric shocks and reduces the risk of electrical fires.
But if your RCD keeps tripping for no obvious reason, that’s a sign that something in your electrical system isn’t quite right. Let’s go through a list of what causes an RCD to trip as well as ways to troubleshoot the issues.
Overloaded Circuits
One of the most common reasons an RCD trips is an overloaded circuit. This happens when you have too many electrical devices pulling power from the same circuit, pushing it beyond its limit. When this happens, the RCD steps in and shuts everything down to prevent overheating and potential fire hazards.
Sometimes, an RCD can be overly sensitive. If multiple appliances with tiny amounts of leakage current are running at the same time, the RCD might add them up and trip, even though none of them alone is a big problem.
If your power keeps cutting out, try unplugging everything from that circuit. Reset the RCD and then start plugging devices back in, one at a time. If the RCD trips again when you plug in a specific appliance, you’ve found the culprit. That device is likely faulty and needs to be checked or replaced.
To prevent overloading in the future, try spreading out high-power appliances (heaters, washing machines, and ovens) across different circuits instead of running them all from the same power source. If you happen to have more devices than your current circuit can handle, perhaps you should get another circuit along with an RCD installation to balance the load.
Moisture
Water and electricity don’t mix. When moisture finds its way into your electrical system, whether from humidity, condensation, or a water leak, it can cause leakage currents that trigger your RCD. This is because moisture can mess with the insulation and increase the risk of short circuits.
If your RCD trips and you suspect moisture is the cause, check around power points, switches, and electrical panels for any signs of dampness. If you find any, the first step is identifying where the moisture is coming from.
It could be a plumbing issue, condensation in a poorly ventilated area, or even rainwater sneaking in from outside. Once you’ve addressed the source, drying out the affected area and sealing any entry points can help prevent it from happening again.
If moisture is a constant issue, then you have to consider waterproofing enclosures and improving ventilation in problem areas.
Damaged Wiring
As time passes, electrical wiring is likely to deteriorate due to general wear and tear, rodent damage, or poor installation. If the insulation around your wiring is compromised, electricity can leak out, and of course, this can cause your RCD to trip.
If you suspect faulty wiring, it’s time to call in a professional. An electrician can inspect your system, identify damaged wires, and replace them before they cause bigger problems. Regular maintenance, including RCD testing and routine checks of your switchboard, can help catch wiring issues early before they become dangerous.
Earth Leakage
Earth leakage happens when electricity finds an unintended path to the ground. Your RCD is specifically designed to detect this and shut off power before it becomes a serious risk.
Faulty appliances, moisture issues, and damaged wiring are the usual suspects behind earth leakage. The best way to minimise the risk is by testing appliances regularly, ensuring proper insulation, and keeping an eye out for signs of moisture.
If your RCD keeps tripping due to earth leakage and you can’t pinpoint the cause, getting an electrician involved is best for your overall safety.
Faulty RCD Installation or a Defective RCD
If your RCD is old, damaged, or was improperly installed, it may start tripping continuously, even when there’s no actual fault in the system. A faulty RCD can mistakenly detect leakage currents or fail to reset properly.
When other causes have been ruled out and your RCD keeps tripping, it might be time to have it inspected or replaced. A professional electrician can test the device to determine whether it’s functioning correctly.
Proper RCD installation is crucial to ensure reliable protection, so if your RCD is faulty, replacing it with a high-quality unit can prevent unnecessary disruptions.
Faulty Appliances
Sometimes, what causes an RCD to trip isn’t in your wiring but in your appliances. A faulty washing machine, refrigerator or even a power tool can create an imbalance in the electrical current. It’s this imbalance that causes your RCD to trip.
To figure out if an appliance is the problem, unplug everything and reset the RCD. Then, start plugging things back in one by one. If the RCD trips when you plug in a certain device, you’ve found your culprit. That appliance needs to be repaired or replaced.
To avoid future problems, make it a habit to service your appliances regularly. Faulty devices don’t just trip RCDs; they can also be fire hazards.
When to Call a Professional Electrician for Your Tripping RCD
Sometimes, by simply unplugging a faulty appliance or redistributing your electrical load, you can fix an RCD issue. But if your RCD keeps tripping and you can’t figure out why, your next course of action should be hiring a competent electrician.
A licensed electrician can run advanced diagnostics, track down hidden faults and make sure your electrical system is safe and up to code. By calling in an electrician, you’re ensuring your safety and that of the building’s occupants, and also staying compliant with Australia’s electrical compliance codes according to AS/NZS 3760:2022.
Also Read: Residential Electrician Services: Expert Solutions for Electrical Safety and Efficiency
