Nigel Molesworth wrote:

On 15 Mar 2006 16:09:52 -0800, pat wrote:


The consumer unit is made by Wylex.


Explains a lot. Replace the 40A fuse with a 40A MCB, all will be well.

You seem to be changing stuff for the sake of it. Without more
information on what is actually installed it is not possible to say
accurately what changes (if any) are required.

There is nothing intrinsically wrong with a cartridge fuse so there may
be no need to replace it with a MCB. In fact in some cases a fuse will
be preferable since it will have a higher current braking capacity.

Regarding the load, A 40A fuse or a 40A MCB will run with a 41A load
indefinitely without tripping or blowing. The real issues here are the
cable - i.e. given the length and the way it is installed will it have
the current carrying capacity, and will it meet the voltage drop
requirements.

Also I see no mention of a RCD on the shower feed - this may also be OK
since it is not absolutely required so long as you can meet the required
disconnection times in the event of a fault etc. Again we come back to
cable size and earth fault loop impedance.



--
Cheers,

John.

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