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New extension - should i change Consumer Unit?

Postby newners » Fri Feb 27, 2009 11:07 am

I'm having a new extension (single room single storey) which will have lighting and 2 sockets fitted from the existing ring main. The extension is being buit under building regulations as the rear the house will open into the new room.

The existing consumer unit although providing no problems whatsoever, is a fuse wire type. It has been suggested to me that when the Electrician comes to wire up the new extension into the existing ring main that the consumer unit MUST be changed to a new circuit breaker one otherwise the electrician cannot issue an electrical certificate for his extension work.

can anyone let me know if this is correct advice or am i just being pressured to to do more work than is absolutely neccessary?

Thanks in advance for any advice
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Postby Click-Sure » Fri Feb 27, 2009 7:29 pm

The electrican will have a lot of trouble saying he has complied with the 17th edition of the wiring regulations if he works on the circuits which that old board of yours is supplying. The issue is not that your consumer unit is of the 'fuse wire' type, but more that there is unlikely to be any kind of RCD protection that meets with the current regs.

He could possibly run all the new wiring in steel conduit or cable with an earthed aromour and use rcd sockets, but it will just end up costing you a lot more. My advise, accept that a consumer unit upgrade it about due and be happy that you and your family will be safer as a result.
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Postby newners » Fri Feb 27, 2009 8:21 pm

Can anyone please help with the question above?
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Postby moggy1968 » Sat Feb 28, 2009 1:16 pm

It is very common on conservatories to run the wiring as a fused spur from the ring main. this is your easiest option. If you are only going to have 2 sockets that shouldn't be a problem. Use an RCD fused spur, available for about £25. from this you take a feed to your light,which will need to be in 2.5 twin and earth to another fused spur rated at 5amps (no need for an RCD on this one as it is protected already by the other fused spur). from there the light circuit can be run. going back to your RCD fused spur you then take a leg in 2.5 to your 2 sockets.

you need to be a bit careful what you run as the total load of these 2 sockets is protected by a 13amp fuse in the RCD FCU.

This of course all assumes your exisiting installation is in good condition with appropriate main and supplementary bonding. there is nothing wrong with keeping a rewirable fuse board as long as the rest of the installation is in good condition (contrary to the letters currently being sent out by some electrical suppliers)

As this method is an extension to an existing circuit it does not require an installation certificate. A minor works is adequate.
you will need to change your fuse board at some stage but guess you would rather avoid having this done at the same time as your conservatory and save yourself a few hundred pounds. of course if you have the money allocate you may decide now is the time to bring your installation up to scratch.

The choice is yours but at least now you have some options.

hope that clears that up. your electrician should be aware of all the above, if not, change your electrician!!
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