consumer unit load

[tj99]

i am currently in the process of installing a 8.5 kw shower but i am unsure about my c/u load
it says 63 amp load and it is a wylex board with mcbs is has in use 30amp,30amp,5amp,5amp,30amp-cooker not in use .
and it also has one spare way.
could i use this spare way for a 45 amp sh0wer fuse ?
or will i need a seperate board for shower.
Any Help please

 

[breezer]

you have asked that in a similar way before, see here

 

[tj99]

sorry breezer to be repetative but the manual for the shower says that a second single c/u may need to be installed for the shower if the load is lower that 80amp
but if you say its ok then i'me happy

 

[ban-all-sheds]

Be fair, Breezer - that shower is going to take more than half the capacity of his board. It will probably still be OK, as he doesn't have an electric cooker, but even so he's got less than 7kW left. You can't blame him for wanting to make sure he doesn't have to follow the installation instructions.

On thing niggles at me though - a 63A 6-way board - I wonder how old it is?

tj - does your CU have a 30mA RCD? If yes, then you can supply the shower from it (put the 40A breaker nearest the switch), but do bear in mind that you won't much capacity left - if you heat your house or your water electrically, and have a kettle, you may come unstuck.

If no, then you will need a separate one, either fed from the CU, or in the form of an RCBO if available for your CU, but in both cases the capacity issue remains.

But if you're contemplating a separately fed shower unit like this:

then you might be better off just investing in a new CU with inbuilt RCD, a higher capacity main breaker and more circuits.