replacing a shower max rating

[lilac]

I have removed a gainsborough sovereign - possibly 8kw but no sticker - got that from shower doc website - the cable is possibly 6amp ? black and red but goes into a 32 amp fuse on a seperate circuit on the rcd box - can i replace with a 9.5 kw ?
or will the lights go out ?

 

[lilac]

sorry do I mean 6 mm cable not 6amp !

 

[lilac]

the shower I want to use is 8.7 - 9.5 at 230-240 and the box says it needs 30MA

 

[rebuke]

You mean 30mA - that will be about a required RCD, if a shower needed 30MA (Mega Amps) that would be one powerful shower!

The max capacity of 6mm cable depends on the installation method, and length. A quick calculation shows you'd only get away with 6mm for 9.5KW shower if it was clipped direct all the way, i.e. not buried in a wall / above a ceiling etc, which seems very unlikely, so you would need to either get a less powerful shower, or upgrade the cable to 10mm (and put an appropriate breaker in).

Note however that this work would most likely be notifiable under Part P, swapping the shower out using existing cabling etc may not be (I can't remember the exact rules), but certainly replacing the cable and breaker would, as it would effectively be a new circuit...

 

[ban-all-sheds]

The best way to change or add to posts is to click this:

I have removed a gainsborough sovereign - possibly 8kw but no sticker - got that from shower doc website - the cable is possibly 6amp ? black and red but goes into a 32 amp fuse on a seperate circuit on the rcd box - can i replace with a 9.5 kw ?

Not without increasing the rating of the MCB, which will probably mean increasing the size of the cable. See here for why.

sorry do I mean 6 mm cable not 6amp !

Are you measuring it, or reading what it says on it? If the former, what are you measuring?

the shower I want to use is 8.7 - 9.5 at 230-240 and the box says it needs 30MA

That'll be a 30mA RCD.

See this for an explanation of choosing the cable you need, but as your knowledge doesn't yet extend as far as knowing how to work out what current an appliance draws you would be much better advised to click on this, particularly as the work needed is notifiable (see //www.diynot.com/wiki/electrics:part-p).

 

[lilac]

the cable goes between the wall space up into the attic and down - what is the highest W shower I could use - the last was prob 8 but they seem to be 8.5 now

I meant 30 whatevers sorry

 

[ban-all-sheds]

the cable goes between the wall space up into the attic and down - what is the highest W shower I could use

Ask your electrician.

 

[Vicario]

I had a 9.8kw shower installed in the summer. Quite honestly, it's too powerful, as the hottest setting is far too hot for a shower. I'd stick to a newer shower at the original kw. I think that the highest setting is because the water coming in could be very cold in winter, but even during the recent cold snap we only needed the heat setting on the shower set at about two thirds of the maximum. If you live in the middle of the countryside with very cold mains water, you might just need the 9.5kw. I'm in suburban London where the water is never that cold, to be honest.

 

[ban-all-sheds]

It all depends on the flow rate he wants and the temperature he wants.

A powerful shower will be able to maintain a decent flow rate even in winter, which might be what he wants - better to be too powerful than not powerful enough, and if he chooses one with thermostatic controls it won't cost any more to run.