Dilemma over replacement of a Consumer Unit

[Teachmesomethingnew]

My parents are in the process of replacing their kitchen, and need to have some electrical work done (moving sockets). The electrician who came (part of the fitting team) said that any electrical work must include a Consumer Unit upgrade to one with inbuilt RCDs. The replacement of their CU was priced at £250. My Dad suggested that fitting RCDs into the existing fusebox (which is about 18 years old) would be cheaper and just as effective. The electricitian said that was not acceptable any longer/under new rules, and the CU MUST be replaced.

Is this the case, or is the electrician charging for unnecessary work? I don't want my folks haviung to pay for something that does not need doing.

Thanks

Andy

 

[dingbat]

The problem that faces the electrician is that any additional sockets must have RCD protection as they can very readily be used to supply portable equipment outdoors. There is no regulation, however, that requires the upgrading of circuits that are not being modified.

If you have, as you've stated, a fuseboard, there is no way you can modify it to have built-in RCD protection. Even with modern circuit breakers it is unlikely that you'll get RCBOs to fit (and if you do they can cost the earth!), so your dad's suggestion is almost certainly a non-starter.

It might be possible to fit a stand-alone RCD to protect just the kitchen socket circuit. But there will be a cost associated with this as well. It can sometimes be more expensive to find another way round.

Trouble is, without seeing the installation it is difficult to advise as there are always a number of issues such as overcrowding of existing fuseways, provision of earthing and equipotential bonding, loading, etc, which need to be checked/upgraded.

On balance a CU change is a good idea because it should involve a test of the whole installation, not just the kitchen - and £250 is a good price. Just make sure you get a full installation certificate for the work. And before you agree, you could always try getting quotes from other electricians.

 

[Teachmesomethingnew]

The fuseboard is an old style Consumer unit which has plug in re-wirable fuses. In my house these have been replaced with little RCDs which ping off when a fault is detected and can be re-set by flicking the little grey flap things back to the on position. My fuseboard/consumer unit is identical to my dads one.

Does this make any difference?

Andy

 

[Adam_151]

In my house these have been replaced with little RCDs which ping off when a fault is detected and can be re-set by flicking the little grey flap things back to the on position

They are MCBs, not RCDs

 

[dingbat]

As Adam says the replacement devices you have are Miniature Circuit Breakers (MCBs). These provide only the same kind of protection as fuses - overcurrent and short-circuit - albeit in a more convenient fashion. This is not what your electrician is talking about.

A Residual Current Device (RCD) detects leakage of current from a circuit, typically when you are providing an alternative path to earth by touching a live conductor! This form of shock protection is now required (and has been for some 15 years!) for sockets that may reasonably be used to power portable equipment outdoors.

You can't buy plug-in RCDs for old fuse boards.