Consumer units are more commonly known as fuse boards or fuse boxes. And if your installation is pre 1995, the chances are that your consumer unit will look like one of these.

Consumer unit Consumer unit Consumer unit

If it does, let me tell you about its shortcomings. While the unit will serve well to isolate your supply, it will only give you limited protection to the wiring from a short circuit in an appliance, or in the event of putting a nail through a cable. If the fuse blows you will need to remove the fuse and fit in a new length of suitable fuse wire.

Latest Part P building regulations require a whole lot more from a consumer unit:

  1. To protect the circuit, and more importantly should you accidentally nail or drill in to a wire buried in the wall
  2. To protect you from electric shock whilst operating electrical equipment outside. For example, cutting through the lead of the hedge cutter, or lawn mower
New consumer unit

The latest generation consumer units achieve this by components called RCDs and RCBOS that detect a leak of electrical current to earth. The faulty circuit can easily be visually identified as the ‘trip switch’ will fall to the off position. After the fault has been addressed the trip switch is easily reset by turning it back on. No rewiring.

These trips are much more sensitive and react many times quicker than the old style fuse boxes so are safer, the risk of fire from overheated wiring in event of a short or rodent damage is reduced. Should the element in your electric kettle fail the RCD will trip rather than you getting a shock from it metal case.

So you can see whilst your existing fuse box is doing a job there are many pluses with an up to date system.

I will be happy to give you more information on replacing a consumer unit together with any addition work that may be required.

PLEASE NOTE: Consumer unit changes should be carried out by a Part P registered electrician and notified to the local council. This is not a DIY job! A complete test of the wiring is always carried out before changing and any problems discovered corrected first. Earth bonding may also require improving to 17th edition regulations as well.

Price for consumer unit upgrades start at around £400 depending upon the number of circuits served, position of existing ‘fuse box’, condition of wiring and the type of new consumer unit required.

Clacton electrician home page