shower?

[gary moore]

can i install my new electric shower on my old cooker curcuit cable(6MM).I now have gas hob with 13amp plug in to the mains oven.shower is 8.4Kw,

thanks for any advise GM

[Christian McArdle]

Only if it has holes to fit a padlock in the off position.

These will allow between 7.2kW and 7.7kW, if we are generous and allow 240V for our calculations. The shower is 8.4kW. I'd go with a 40A/30mA Type B RCBO. The thought of having an instananeous shower on a rewirable fuse with no RCD makes my spine shudder (and will probably make your's shudder pretty uncontrollably in the event of an earth fault).

I haven't got the tables in front to check the cable's suitability. 6mm seems marginal and certainly needs to be calculated properly to be sure it is suitable.

Christian.

[BigWallop]

My apologies. Thank you Christian. I did mean a 40 Amp type B MCB, but my mind was on another job where the situation called for a 32 Amp MCB.

Old age doesn't come itself, Eh ? :-))

[Chippy]

Bearing in mind the duty cycle of an electric shower, wouldn't the overloading be tolerable, in practice? I know of at least one installation with an 8.5 kW shower on a 32A breaker.

If the OP is using a former cooker circuit, he might be well advised to move it to the RCD protected side of his CU.

Also, he isn't running his new oven from the 13A outlet on the cooker switch, is he?

[Christian McArdle]

I'd be amazed if it didn't work, I have to say. I don't have the curves in front of me, but suspect a 10% overload would take tens of minutes to blow, if ever. It would still be very bad practice, though.

Christian.

[Frisket]

I agree it would probably work but it's the kind of practice reserved for qualified sparkies houses - you know like decorators houses always need painting and plumbers houses still have lead piping etc. etc. ;-) Richard