Tripping rcd troubleshooting

An RCD tripping is referred to as ‘nuisance tripping’ by many. In a large percentage of tests electricians confirm they work as designed. Residual current devices detect imbalances in ovens, sockets and showers. They remove the mains power if the live and neutral go out of balance. Most RCDs tripping under fault conditions will be between 20 and 30 milliseconds – faster than you can blink! ‘Nuisance’ arose because re-wireable fuses and miniature circuit breakers didn’t trip at all! Designed to protect the cables if overload occurred. Fuses and circuit breakers offer no protection from a person coming into contact with a live conductor. RCDs help prevent electrical related injuries and fire. They are a big part of the wiring regulations electricians adhere to.

What causes an rcd to trip: diagnostics you can do yourself.

Top Tip! The first thing to do if you loose mains power is unplug (turning the switch off isn’t the same) everything you can. If you call any electrician for an rcd tripping issue in Plymouth– this is the first thing they will do!

i. Identify what the RCD is protecting. Clarify what the device is protecting and begin the diagnostic process. The rcd device will have a test button. If your consumer unit has one RCD it is protecting all the circuits connected to it. If it has two residual devices it protects everything to the left or right of it. If you have an RCBO (this is an RCD and overload protective device in one unit) it protects one circuit.

If your rcd won’t stay on; something it is protecting may have a developed a fault. Faulty appliances are common. Problems with the wiring are another cause.

ii. With a list of what the RCD is protecting, turn all electrical equipment in the property off. Switch the RCD off by the lever, or by pressing the test button. Make a list of what no longer works. The list will tell you what item(s) or area(s) could be causing the problem.

iii. If you believe the socket circuit is to blame; unplug all the appliances. Add them back one at a time to see if the rcd trips. If you believe to have found a faulty appliance, try it by itself. The combined earth leakage of two items can be enough to trip an RCD although pose no problem used by themselves. This can be a time consuming although valuable exercise. Suspected items can leave the appliance disconnected for a few hours or days if necessary to help confirm.

Appliances unknowingly faulty from a home without RCD protection move to a new one and cause tripping . Portable appliance testing should confirm the fault, but that’s with the help and test equipment from an electrician . Users of the equipment assume a problem with the wiring or electrical installation.

iv. If you think your electric shower is a cause; try turning the isolator off. If the RCD resets this would suggest a fault with the shower. A shower isolator removes the power in the same way unplugging a faulty kettle from its socket would.

v. If the RCD trips are infrequent, make a note of the time. Could it be:

  • An extractor fan in a guest bathroom that isn’t used a lot?
  • A security light that no longer works?
  • That the oven reaches a certain temperature?
  • An outdoor light fitting affected by the weather?

Tried the suggestions to no avail? Maybe the trip is too random or localised to the upstairs lighting for example. You have carried out the first part of the electricians call out and will assist further diagnostics.

Notes that will help you track a tripping rcd .

1. The first time the tripping started.

2. If any work has been carried out on the property or at the time the tripping began. Non-related work like new shelves can cause rcd problems because the wiring has been disturbed unknowingly.

3. If you have purchased any new electrical appliances or had any repaired.

4. Previous unresolved electrical problems.

5. If you, or your neighbours have experienced power cuts.

If you are still having an RCD tripping problem call Goodwin Electrical on 01752 957808 or fill in the contact form