Shower cable

24 Aug 2007
Reaction score
United Kingdom
Hi All, would 6mm cable on a 9 metre run using a 40 amp mcb, be sufficient for a 8.5kw shower? The consumer unit has a built in rcd. The cable is only buried in the wall for 2.5 ft, the rest is uncovered. (under bath and in the loft space not covered by insulation)
Sponsored Links
These are given directly from quote from books, as such I take no liability:-
8500/230 =37 amps
with reference to the electricians guide to building control
up to 7.2 kw =6mm
upto 9.6 kw =10mm

method 2(buried in wall P210 same as method 1 current capacity)
If you also go by bs7671 regs p220 method 1, max cap 6mm 47 amps

my choice would be 10mm as I have guessed how cable is buried and if the cable was in thermally insulating wall only 34 Amps rated.
******Legally part p it should be fitted by registered installer*******
please understand I wish to cover myself while still answering your question :D
Aardvark Avo said:
******Legally part p it should be fitted by registered installer*******
State where in any official documents it says this.

(Clue: it doesn't. Anywhere.)

The OP may legally DIY as long as he notifys his building control dept who will charge a fee and inspect and test his work! :)

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local

Sponsored Links