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[pc6844]

Hi, i currently have a 9.5kw shower in my upstairs bathroom and the electrics to it are new as the house has already been re-wired prior to moving in. The shower needs replacing in all honesty as its rubbish and i don't have any problem doing it myself. Its the correct size cable for the shower etc and would be a straight swap. I have the old type consumer unit with the fuses which is located at the bottom of my stairs built into the wall (why i don't know) but no fuse circuit for the shower. When i click the fuse off at the board for the sockets it kills the power to the shower, this is where i have my concerns, i believe the shower is run off the sockets ring. Is this acceptable or a big NO NO. The problem now is getting a new cable for a separate circuit from the board to upstairs.

Many thanks

[BLAKEY1963]

PC6884
A shower circuit should be wired on its own dedicated mcb.
9.5 KW , WOULD NEED a mcb of 40 amps rating.
And at least a 10 mm2 Twin and earth cable.
If as you say it is run from a ring main , this could b a serious fire risk.
Part P regs will apply to the new circuit and an electrician should be consulted .

BLAKEY1963

[pc6844]

Many thanks...

Got it totally wrong and i have had a good look at my consumer unit and there is a separate 30A fuse in the board feeding the shower. I didn't look properly as i thought it was a blank spare fuse way.

Just so i don't get ripped off by an electrician when it comes to do the work, the shower that we were looking at is 9.8kw and requires a 45A fuse... My question is it a matter of just changing my 30A fuse to a 45A fuse? The cable already installed is 10mm. My consumer unit is the old Wylex type.

My main concern is that my old Wylex states not to exceed 100amps but it has in at the minute a total of 120amps (45A fuse for cooker, 30A fuse for sockets, 5A fuse for water heater, 2 x 5A fuses for lights and 30A fuse for shower) thats without changing a 30A for a 45A!!

[moggy1968]

it's no problem fitting the new fuse to your board if the cable is already 10mm, nice of someone to overrate the circuit for you previously!! finding a 45A fusae may be a challenge but they are out there.
my understanding is this doean't require part p registration either as this is a like for like swap, even though the fuse has to be changed.
don't worry about your main fuse, your allowed to apply a thing called diversity when calculating total load, you don't just add up the maximum load of everything (most houses would pull more than 100amps if you did!)
Of a much bigger concern is that you say the house has been recently rewired, in which case why do you still have a fuse board? thats a complete no no and breaches the regs that would have been in place at the time in oh so many ways.

[BLAKEY1963]

PC6844

YOUR ratings of current are subject to wats called divercity
BS7671 , would list typical allowances for domestic properties
on the demand of different circuits u have.
YOUR electrician could help 2 explain this 2 u .
If you have not got rcd protection , currently , u would need
to have that installed.

BLAKEY1963