Advice on shower fitting

[shaw7380]

I have been advised by an electrician (or claims to be) that if fitting a 8.5kw shower I require 6mm cable and a 45amp breaker.

My understanding from research, is that it should in fact be 10mm cable and a 40amp breaker. The cable run is through a loft and down inside a cupboard and approx over 7metres.

Any advise to confirm which is right..?

 

[securespark]

40A OK for 8.5.

May as well go for 10mm² - then if you want to upgrade, you don't have to replace the cable.

May as well mention Part P...unless you are north of the border.

 

[baldelectrician]

45 A breaker, i would always use 10mm cable, the cable rating has to be able to take the load from a mcb.
In other words if you put a 7 Kw shower on a 50A mcb the cable sould be able to take the load the mcb may pass- someone may change shower for one of a higher rating at a later date.

You could get away with (maybe subject to site conditions) a 6mm cable and a 40A mbc, but just don't do it. That will 'future proof' the install.

 

[securespark]

Surely to future-proof it, you should use a 50A breaker with 10 mm² cable and everything else to match.

 

[ban-all-sheds]

I have been advised by an electrician (or claims to be) that if fitting a 8.5kw shower I require 6mm cable and a 45amp breaker.

My understanding from research, is that it should in fact be 10mm cable and a 40amp breaker. The cable run is through a loft and down inside a cupboard and approx over 7metres.

Any advise to confirm which is right..?

Bit of each, really - 6mm² cable is OK for an 8.5kW shower, but not with a 45A breaker - that might be a bit high for the cable given where it runs, and anyway 40A will be fine for the load of the shower.

//www.diynot.com/forums/viewtopic.php?p=81696#81696

But as said by the others - if you are putting in a new cable, use 10mm².

 

[shaw7380]

Thanks very much lads you have put my mind at ease.