Electric shower cable size......again!

[andywatson]

Hi all,

I am not an electrician at all, but I do have a very competent friend who is going to install an electric shower for me- but he has given me a shopping list of what to buy.

I have done a load of research, and I am seeing that people are recommending 10mm cable for a 9kW shower, and 40A fuses.

I have seen a 25m section of 6mm cable at B&Q for £30 ish, but I would need to buy 50m of 10mm (they don't sell a 25m pack) which is £100. The 6mm cable is rated as good for carrying 47amps (10mm is rated at 64amps), so surely the fuses would trip before there was any issue with the cable, and I can save a very important £70?

Thanks

Andy

 

[Spark123]

The size of the cable required depends on its rating, how long it is and how it is installed. The 47A for 6mm will be with it installed clipped direct in an ambient temp not exceeding 30ºC, away from other cables and away from thermal insulation. How long is the cable run?
It is usually worthwhile installing 10mm² in case you want upgrade to a larger shower at a later date.
The shower also needs to included in the supplementary bonding arrangements.
Instead of B&Q, have you tried an electrical wholesaler / independant retailer? TLC do 10mm² at £3.22/M.
Please note that this work is notifiable to LABC under Part P of the building regs in England and Wales.

 

[Adam_151]

screwfix have 25m of 10mm for about £60

also I know it sounds silly, but try wilkinson, they sell cable at quite a slow rate and I don't think the recent rises of copper prices have come through to their prices yet (well at least their prices seemed very good when I was in a week or so ago)

 

[plugwash]

btw TLC have 10mm red/black T&E at £2 a meter

 

[RF Lighting]

We use a local independant wholesaler who sell 10mm² at £1.70 + VAT per meter.

If you want to save those all important £££s, then go to an electrical wholesaler, who will sell the cable cheaper than Q+B and sell it by the meter too, so you don't end up buying more than you need.