Shower cable size

[mick21]

Hi Guys
Does a 9.5kw shower require 6mm cable or 10mm shower is approx 10 mtrs away from consumer unit most of the cable will be ran in the loft space, I know its border line but what would you guys use......thanks in advance.

 

[james the spark]

Always go for the larger if unsure in my opinion.

 

[alanl]

I did exactly this earlier this week.
Cable calculations do allow 6mm clipped direct,i.e. with no insulation round the cable. But, I think insulation will be put on top of the cable in the future, so I erred on the side of caution, and put in 10mm. The price difference in the cable is minimal (for the 13m run I did, maybe £7 difference), and it is future proof for a bigger shower, as well as ensuring it meets all the Regs if the loft get further insulation.

TBH, I cannot see why anyone would use 6mm for a new shower any more.

HTH
Alan.

 

[PC Electrics]

Hi Guys
Does a 9.5kw shower require 6mm cable or 10mm

Well, that depends upon the installation method.
If the cable is installed 'clipped direct' (ie no insulation) then 6mm has a rating of 47A in BS7671.
As a 9.5kW shower pulls 39.6A then the load is well in.
As the load would be 'occasional' rather than 'continuous' you'd be okay on a 40A mcb.

I keep shower cable clear of insulation by mounting up on woodwork and where it passes through the insulation layer I use 4 inch soil pipe to maintain a large 'air gap' around the cable.

 

[RWJ]

Just had the same conversation with a guy going for his DI assesment, he was told to put in 16mm for a 9.5kw, 10m run under floorboards. I did tell him to redo the calculations as I thought 16mm was overkill.

 

[tony mc]

Putting 16 mm into the switch will be interesting!!!

 

[RWJ]

Think I convinced him enough to use 10mm

 

[Octopus]

10mm cable every time and I'd recommend use of the Crabtree 50A pull switch

 

[PC Electrics]

Size the cable according to BS7671 !! But I agree about the Crabtree switch.

 

[RWJ]

Just had the same conversation with a guy going for his DI assesment, he was told to put in 16mm for a 9.5kw, 10m run under floorboards. I did tell him to redo the calculations as I thought 16mm was overkill.

Just like I advised the guy you mean??

 

[telectrix]

showe me a 9.5KW shower that draws 9.5KW and i'll start looking out the window for flying pigs. never seen a 9.5KW draw more than 32A. over rated by manufacturers to push sales. the old 7kw got you just as wet.