Fuse and Consumer Units

Replacement Fuse Box

The 17th edition of the wiring regulations requires most circuits in a domestic property to be protected by a Residual Current Device (“RCD”). An RCD is a life saving device which is designed to prevent you from getting a fatal electric shock if you touch something live, such as a bare wire. It can also provide some protection against electrical fires.

What is a consumer unit?

Modern Fuseboards, Mains Boards, or now commonly referred to as Consumer Units (C.U.) generally consist of these components:

A Main Switch – this does not act as a safety device and is just there to manually turn off the power to your home.

An MCB for each circuit – Instead of old rewirable fuses, you now have MCBs (miniature circuit breakers), basically a switch which automatically switches itself off when it detects that the circuit is overloaded, i.e. a 6amp MCB will switch off when it detects anything over 6 amps on its circuit. No rewiring of the fuse is needed, when the fault has cleared, you simply switch it back on. MCBs are much more reliable, easier to use and safer than old rewirable fuses. It is not unknown for old rewirable fuses and their fuseboards to set on fire or explode, spitting out molten copper and tin, when certain types of extreme faults occur.

What is an Residual Current Device?

RCDs do not detect whether a circuit is overloaded or not, rather it detects the integrity of the circuit. If there is damage to a cable, compromise as a result of water or a faulty appliance, an electrical current will flow where it shouldn’t and could cause an electric shock before the circuit is overloaded. Consequently an MCB does not always offer complete protection. By detecting even the most minute fault currents and having a split second disconnection time, RCDs protect from electric shocks, or at the very minimum, injury from electric shock.

When is an RCD required?

New requirements set in the 17th edition regulations state that there should be RCD protection for sockets, the electrics in your bathroom or shower room, circuits intended to supply mobile equipment outdoors and for cables buried in walls. Since the wiring in most of the homes up and down the country runs underneath the plaster of the walls, it means every circuit in your home should be RCD protected.

Reasons to have your consumer unit replaced

Replacing your consumer unit improves the standard of safety in your home and protects you and/or your family.

If you ever have electrical work carried out in your home such as having new lighting, shower or socket circuits, and you don’t want to have new consumer unit when it is needed, the electrician will have to install a separate smaller consumer unit so that the newly installed work meets current regulations. Not only will this make the job relatively expensive, it will lead to you having multiple consumer units in your home and the possibility of having to pay for further smaller consumer units in the future. It is normally preferable to have a new consumer unit installed at the earliest opportunity, i.e. when having an electric shower installed or having a new kitchen fitted, and one that incorporates all the circuits in your home and also has a little space left to add more circuits in the future if you ever decide to have more electrical work done..

House rewires

Complete or partial home rewires

Most rewires to domestic properties come about for one or more of the following reasons.

  • As a result of an inspection report
  • Observations made by others, whilst work has been carried out
  • Problems with sockets or lights not working
  • Old light fittings, sockets and wiring
  • Insufficient sockets and light points

It may be that the installation is worn and does not have an up-to-date fuse board, and as such would not conform to today’s wiring regulations (BS7671). However that’s not to say that the whole installation will need replacing. You may find that by installing a new fuse board and the replacement of a few sockets and/or light fittings, it could be brought up-to-date. To establish just what the condition is of your installation, you should have a Periodic Inspection Report (PIR) carried out which would then identify any areas that need attention.

Remember a rewire is the most disruptive and invasive work that a property can undergo. The best time to have this work carried out is before you move in, so if possible try to find out if your new home needs a rewire before you move in. However if you are now happily living in your home which is in need of a rewire, there are a couple of ways the work could be carried out which we can assist with.

Modern houses place a much higher demand on the electrical system than in years past, so if you have antiquate wiring it is an accident waiting to happen. Even if the safety issues aren’t enough to convince you, you will have to get your electrics updated before you sell your house or rent it out; a basic electrical periodic inspection report will reveal any inadequate or defective electrical systems and prove if a building or home is electrically safe. No mortgage lender will lend money on a house that could be a potential fire hazard.

If you have concerns about the electrical systems in your property then contact Barton Knight Electrical using our simple contact form or by telephoning us directly on 0800 005 1005.