Fuseboxes with RCDs
Modern domestic fuseboxes (consumer units) are usually fitted with one or more RCDs (residual current devices). If yours doesn’t contain any RDCs you should definitely think about upgrading your fusebox to one that does. This is because an RCD is a very important part of a fusebox. Its purpose is to protect you from electric shocks and your property from electrical fires. It does this by constantly monitoring the electric circuits in your property for leaking current caused by earth faults. It is an extremely sensitive piece of equipment and can detect even the tiniest of current leakage. If an RCD detects a fault it will automatically cut off the electricity to the problem circuit.
In the picture above, the fuse box has 2 RCDs. The RCD on the left can protect up to 5 circuits (to the right of it) and the RCD on the right can protect another 5 circuits (to the right of it). Each live circuit in this fusebox is protected by a separate MCB (miniature circuit breaker) as shown.
What to do if an RCD trips
It can be a nuisance when an RCD trips but it is a sign that a circuit in your property is unsafe. The most common causes of RCD tripping are faulty appliances but there can be other causes. If an RCD trips i.e. switches to the ‘OFF’ position you can:
- Try resetting the RCD by toggling the RCD switch back to the ‘ON’ position. If the problem with the circuit was a temporary one, this may solve the problem.
- If this does not work and the RCD immediately trips again to the ‘OFF position,
- Switch all the MCBs that the RCD is protecting to the ‘OFF’ position
- Flip the RCD switch back to the ‘ON’ position
- Switch the MCBS to the ‘On’ position, one at a time.
When the RCD trips again you will be able to identify which circuit has the fault. You can then call an electrician and explain the problem.
- It is also possible to try and locate the faulty appliance. You do this by unplugging everything in your property, resetting the RCD to ‘ON’ and then plugging back in each appliance, one at a time. If the RCD trips after plugging in and switching on a particular appliance then you have found your fault. If this does not resolve the problem you should call an electrician for help.
Remember, electricity is extremely dangerous and all problems need to be taken seriously and never ignored. If you are unsure it is always best to call the experts.
Source URL: https://aberdeenelectriciansltd.co.uk/fuseboards/what-to-do-when-rcd-trips/