The current IEE wiring regulations state that all circuits that feed sockets, mobile equipment outdoors, all bathroom electrics and all cables buried in walls must have RCD protection. Most if not all cabling in this country is run in walls so therefore all circuits now need to have RCD protection, older fuse boards and consumer units do not have RCD protection. Any fuse boards or consumer units that do not have RCD protection should be upgraded to modern RCD protected consumer units to ensure the installation complies with current regulations.


RCD’s are the best protection we have to protect us from potentially bad or fatal injuries due to electric shocks, they are designed to protect us from electric shocks form faulty circuit equipment/appliances or wiring.


  • What Is A RCD?

RCD stands for Residual current device, this is a safety device that protects against earth faults that could lead to risk of electric shock. It detects the integrity of a circuit rather than detecting overload. If there was a fault with an appliance, water ingress or overheating somewhere in the electrical installation or a damaged cable electrical current would flow where it shouldn’t and could therefore cause an electric shock, if a fault like this were to occur the RCD would automatically trip in milliseconds and would not reset until the fault has been rectified to protect us from the risk of an electric shock. Whereas an MCB (miniature circuit breaker) only works on overload so wouldn’t trip if one of the faults mentioned above were to occur, leaving you vulnerable to an electric shock and in danger.

A modern consumer unit consists of the following components:

  1. A main switch, this is used as a means of isolating the entire electrical installation rather than as a protective component

  2. RCD’s- There will be 2 RCD’s, these will be split in the consumer unit so that 1 RCD would control half of the MCB’s (miniature circuit breakers) and there circuits and the other RCD controls the other half of the MCB’s and there circuits. This ensures that if a fault were to occur and one of the RCD’s trips only the circuits controlled by that RCD would stop working, so the other RCD and its circuits would continue to work. This way you wouldn’t be in a scenario where no circuits work.

  3. MCB’s (miniature circuit breakers)- these provide protection against overload, if a circuit was being overloaded the MCB would trip but will reset by simply flicking the switch up once the overload has been removed, this is far simpler and safer than the old rewirable fuses that need to be physically rewired every time they blow due to overload

Replacing your consumer unit provides protection and safety in your home for you and your family. If you ever have significant electrical work carried out at your home such as a new circuit you have 2 options:

  1. Upgrade your whole consumer unit to accommodate the new circuit and all the existing circuits

  2. Changing socket and switch faceplates

  3. Install a separate small consumer unit to ensure the new circuit installed has RCD protection to comply with current regulations

It’s recommended to upgrade the whole consumer unit for an RCD protected consumer unit, this way all the existing circuits would have RCD protection and therefore comply with current regulations. You would also have spare ways in the new consumer unit to accommodate any new future circuits, it basically future proofs your consumer unit. A full test and inspection of the electrical installation would be carried out as part of the consumer unit upgrade as well so if there were any underlying faults on the circuits they would be identified and you could plan for any remedial works needed, once the testing and inspection is complete the client would receive an electrical installation certificate for the consumer unit upgrade.

Our staff have all the necessary qualifications and accreditations needed to work successfully in the commercial sector, that combined with our vital experience will ensure all work is completed to the highest standards.

We offer free estimates and cover Surrey and surrounding areas.  
Contact us now for a quote >>