DIY Doctor

consumer unit

Postby greengrass » Tue Dec 07, 2010 1:35 pm

wylex 8way unit wired type plug in fuses want to change to plug in mcb's is it worth doing? i know they will stick out further but presents no problem.
What's a fair price to pay for replacement new type 8 way consumer unit, clear work area on wall and meter same wall in box outside. All tested ok about 3yrs ago by my mate (passed away last year) who was electrics tester with his megga and other testers. He worked for an insurance company and tested our sytem thoroughly and all ok even the fuse box some contractor from S,E said was dangerous, yes it doesn't blow as quick as an mcb fuse but that's the only risky bit.

many thanks
Rank: Foreman
Progress to next rank:
Posts: 286
Joined: Wed Mar 14, 2007 7:27 pm


Simply Build It

Postby ericmark » Tue Dec 07, 2010 8:06 pm

Today re-wireable fuses are only permitted for use by instructed or skilled persons but this of course does not mean you have to change them. However with most electrics one can remain as one is or comply with latest regulations there is no middle ground. So as soon as you change the fuse for a MCB then you should also have RCD protection.

My house has had the converters to MCB fitted for years and two consumer units each supplied from a 30ma at 40ms RCD so in fact does comply with latest regulations but this is unusually and normally it would cost so much to retro-fit RCD's that the new consumer unit would be the way to go.

However the RCD does have some draw backs mainly when fitted to an old house where many items add up to cause the device to trip. And when getting a new consumer unit fitted job one is to test the house and locate the problems before the change so correcting problems can be programmed into the whole job.

There are many ways to do the work with RCBO (MCB and RCD combined), RCD basic, RCD with warning lights, even auto resetting RCD and as a result the price can vary anywhere between £250 to £1000 and what you need to do is decide what level you are looking for.

Not complying with law and just replacing the fuse carrier with a MCB is still a method selected by many but there is no way any electrician is going to tell you to break the law.

There is nothing to stop you adding RCD after the consumer unit but in real terms it would cost more than a new consumer unit.

I would say stage one is get an estimate and ask for three options.
1) Duel RCD
2) Duel RCD with some RCBO's
3) All RCBO's
Then select according to pocket. All RCDO's are best but cost more.
Rank: Project Manager
Posts: 2531
Joined: Fri Oct 02, 2009 8:49 pm
Location: Llanfair Caereinion, Mid Wales.

Postby sparx » Wed Dec 08, 2010 8:04 pm

Ericmarks good evaluation of work ,
however as to costs:
plug in mcb's around £8/9 each= £65/70
+ Rcd in enclosure 80A unit = £65/70 for reasonable quality item
so around £130 ish, plus as notifiable work under LABC Part-P will cost £150 ish to notify if DIY with no test sheets for later reference re insurance/sale etc.

total £280 plus vat,
OR get it done for you at around £350 inc Vat.
complete with notification, test sheets labels etc.

Pays yer money, takes yer choice!
regards Sparx
Rank: Project Manager
Posts: 2166
Joined: Wed Mar 21, 2007 8:33 pm
Location: The fifth continent.

Display posts from previous
Sort by
Order by

  • DIY How to Project Guides
  • DIY how to tutorial projects and guides - Did you know we have a DIY Projects section? Well, if no, then we certainly do! Within this area of our site have literally hundreds of how-to guides and tutorials that cover a huge range of home improvement tasks. Each page also comes with pictures and a video to make completing those jobs even easier!

  • Related Topics