What is the maximum kilowatt we can run off a 30 amp ring main?

Question

We are looking to fit a new shower...Answers would be much appreciated!

We are trying to buy a new shower to replace a very old one, but were not sure what kilowattage I can buy as there don't seem to be many available under 8 and a half kw. Just want to make sure that is safe.
I think the one that we are replacing says maximum of 8 kilo watts.

Thanks for your help. What other choices do I have without having to re-wire half my flat? Power shower maybe?

Answer 1

You can run 7kw off a ring main, but you cannot/must not in any way run a shower from it. You must run (have run) a separate cable from a dedicated circuit breaker with RCD protection. I strongly suggest that you contact a qualified electrician for advice. Bathroom electrical regulations are very strict and fall under part P.

Answer 2

If its an electric shower it would need a separate circuit from your fuse box to a switch in the bathroom using a heavy 6mm or 10mm cable depending on the kw of the shower you choose. You cant take it off the 30 amp socket ring circuit as it is to much of a load and against electrical regulations. Make sure who does it is registered to carry out electrical work.

Answer 3

6900watts is max power for a 30Amp circuit ( P=IV, therefore 230v X 30a = 6900w)

BUT, do not connect a shower to this at all!!

It is not necessary to have an RCD fitted, despite this probably causing much disagreement with the sparkys out there. Its all to do with fast disconnection times and some times, given a sufficiently high value of PFC, a fuse might trip faster than an rcd.

Also, did you realise that to fit a safe supply for your shower is actually illegal for you to do it.
you must get a qualified spark to do this as work within a bathroom/shower room is notifiable to building control.

If you do this yourself, you might find that you will have problems selling your house in the future due to these "HIPS" coming into force soon.

Electricity-- very very simple, yet surprisingly lethal.

Spend the money on a sparky, live longer ;-)

Answer 4

Your choice is to get a registered electrician, this is your only choice.
To work in any domestic setting requires part P of building regs or work pre- authorised by the building inspector.
Electrical work is becoming as regulated as gas work now days, it is very well doing this sort of work yourself but if someone is injured due to an error, the liability will be on you along with the law against you.

Answer 5

I would go with Bob B 's answer regulations are being updated all the time , I'm forever going on courses they keep shortening the expiry dates on grading cards and other periodic bumph , too many cowboys out there so choose wisely.

Answer 6

for a shower u must go right back to ur consumer unit on a separate fuse

Answer 7

I think that you are limited to 3 Kw max by regulations

Answer 8

Another spark to agree with nik-name

Answer 9

My cheap, chinese made calculator says about 6600 watts (6.6kw)