Will shower overload rcd?

[chris1234]

Im in the process of installing an 8.5kw shower into the bathroom of a small flat

The current set-up in the cu is as follows;

100A main switch
63A 30mA rcd side of cu;
30A running cooker and 13A socket
30A ring running 3 x double socket, 2 x single socket
30A ring running 2 x double
30A running 1 kitchen extractor & 2 heaters (heaters permanently out of use)
16A running socket for washing m/c, dryer and microwave

non rcd side of cu;
15A running water heater
5A running lights
5A running lights

If I install 40A mcb on rcd side of cu will it overload?
i dont use too much at the same time, worst case scenario shower, cooker, kettle, washing m/c, dryer, 3-4 sockets and a few lights at once

Or would it be better to install the mcb on the non rcd side of the cu run it to a separate rcd then to the 45A switch?

Any help would be greatly appreciated
Thanx

 

[andy]

should be OK. and are you aware of part P?

 

[chris1234]

thanx for the reply

Yeh, aware of part p trying to do everything by the book before i get part p qualified bod to check it over (probably not the best way to operate i know)

Also when connecting the rcd what is the best way of continuing the earth as i will obviously be interupting the phase and neutral?

thanx again

 

[Adam_151]

Have you checked to see if an RCBO is available for your board, that would be neater?

 

[andy]

Also when connecting the rcd what is the best way of continuing the earth as i will obviously be interupting the phase and neutral?

thanx again

?

you will connect the circuit as a normal circuit. neutral to the neutral bar, phase to the MCB and earth to the earth bar

 

[Adam_151]

?

He is talking about if he puts the mcb on the non-rcd side of the cu and uses an rcd in a separate enclosure, and wants to know how to join earth in this enclosure as obviously it doesn't pass through the rcd like live and neutral do.

Its a bit messy like that, I'd personnaly swap the rcd out for one with higher switching capacity, or use an rcbo on the non rcd side

 

[securespark]

If you are going to run a shower circuit from the RCD side of the board, then I would replace the 63A RCD for an 80A one.