At Jim’s Test & Tag, we are experts in electrical safety. RCDs (residual current devices) serve as protection against electrical shock and electrocution. Everyone needs a functional switch installed in their building (or connected to their appliances) for maximum protection.

If your residual current device has been tripping (turning off the power), you might be wondering “why does the RCD trip?”. There are a number of reasons that can cause an RCD to trip. Check out the rest of our blog to find out more about this life-saving device.

Why does the RCD trip?

RCDs trip when a fault is detected in an electrical circuit.

When an RCD trips frequently (even after resetting), it is probably responding to a damaged electrical appliance. This means your switch is working correctly.

If you’re troubleshooting the cause of your RCD trip, we’ve made a list of possible causes for an electrical fault. Check out these common issues and eliminate frequent interruption to your power supply.

Common RCD Switch Responses

why does the rcd tripBroken electrical appliances

Old washing machines, kettles, toasters, fridges, and freezers can become dangerous with age.

Sometimes, your old kettle might be fine to use on its own, but if you’re running the washing machine at the same time, the power switches off. This means your kettle needs replacing.

Just because the appliance works properly most of the time, that doesn’t mean it’s safe. The tripping of the circuit whilst other appliances are in use is a symptom of a hidden problem with your kettle. It will just get worse as your appliances age, so you need to replace it ASAP.

If you’re working off-site, a portable RCD  can be attached to your equipment for protection.

Dangerous electrical wiring –why does the rcd trip

The answer could be hiding inside the walls of your building. Faulty electrical wiring can cause a short circuit. A short circuit happens when electrical current travels outside of its intended path and bypasses it’s intended destination. Because the power hasn’t reached the resistor (for example, a light bulb), the current continues to travel around the circuit with the same voltage it started with. When a circuit is functioning properly, a current would pass through the destination (the light bulb) and the voltage would be reduced as power is supplied to it. Because this voltage is not used in a short circuit, the current causes the wires to heat up. This can result in fire or electrical shock.

In the case of a short circuit, it is actually the circuit breaker that turns off the power – not the RCD as is commonly the mistake. Most RCDs in buildings are accompanied by circuit breakers.

Luckily, your circuit breaker is designed to intervein when a short circuit is detected in your building. Faulty electrical wiring can be down to aged wires that have become fragile over time and lost their insulation.

Ground fault –

A ground fault happens when an electrical current travels along an unintended path and makes a connection with a grounded surface. If you provide a pathway for the current to travel to the ground with your body, you may be electrocuted.

Ground fault examples:

  • If someone puts a metal knife in a toaster, the metal conducts the electricity and interferes with the intended path of the current. We conduct electricity with our bodies – so the electricity will pass through the knife, the body, and then travel into the ground.
  • If a plugged-in hair dryer falls into a bathtub full of water, the water (an electrical conductor) will divert the path of the electricity into the tub. The electricity will escape into the ground via the person in the bath as they contact the sides of the tub.

RCD Testing

Why does the RCD trip? To protect you from electrical shock, electrocution, and fire. Now that you understand the importance of the residual current device, you need to invest in maintenance. At Jim’s Test & Tag, we conduct electrical risk assessments for businesses across the nation. If you own or manage a property, you need to make sure a working RCD is protecting any occupants from hazards.

We test both portable and fixed (located in the switchboard) RCDs. Ask us to visit your property today and make sure your currents are protected.

Your devices should be inspected regularly. If you have any questions about the frequency of tests, get in touch with us and we can give you more information.

If you suspect that your appliances and/or equipment are causing your RCD to trip, contact us today. We test and tag all appliances so we can let you know if your equipment is safe for use.

Why does the RCD trip? Find out more now. Call us on 0800 454 654 or fill in the online form for a free quote.