Bathroom wiring

[young sparky]

hi, been asked to do a small job for a customer, im puttin a light inside his shower but instead of having the light switching with other lights in the bathroom he wants it switching when he pulls the pullcord for the shower... to do this i was going to break into the cable going from the pullcord to the shower with henley block then out to a fused spur, from ther with a bit of 1mm cable fused at 3amp to the light, does this sound ok?

 

[giio]

an electric shower must be on it's own dedicated circuit and not shared with any other device

 

[young sparky]

yes i have explained this but he wants the light on with this pullcord, if there is any safety issues i will be wiring all lights off the lighting circuit but just checking to make sure all would be safe before i done this

 

[giio]

he can't have it from you, that is the answer,tell him it contravenes the regs and you're not prepared to do that under any circumstances, and if he really wants a cowboy to do his installation then he will have to find his own and suffer the consequences

 

[malcolmsanford]

Is this not a double thread ????

 

[benji]

what about fitting a reed switch (flow switch) to water feed to shower to switch light on/off

 

[alanl]

an electric shower must be on it's own dedicated circuit and not shared with any other device

I've never heard of that before. Where is that in the Regs or OSG?
Ta
Alan.

 

[giio]

if your going down that road then a light with a proximity switch would be much simpler

 

[Southern Spark]

You can overcome it if you do it via a contactor. This will keep the circuits separate, but switching together.

 

[giio]

if the shower circuit operated the coil,the the shower would not be on it's own dedicated circuit, therefore the light would have to operate the coil making the contactor cumbersome to say the least, I still think sourcing a light with a proximity switch, or fitting a proximity/pir switch to operate the light is the simplest and most economical ,bearing in mind any regs to be overcome as in siting of a separate proximity switch

 

[alanl]

Again, could you point to where it is in the Regs that a shower has to be the only thing on its circuit?
Alan.

 

[geoffa]

The only reference i'm aware of, to that is on page 161 of the OSG section 8.5
section simply says that water heaters fitted to storage vessels having a capacity of 15litres or more....... should be supplied by their own separate circuit.
A shower wouldn't apply to this however.

Obviously the restriction to the circuit dedicated to the shower would be the current rating of the MCB or RCBO and cable size for the safe operation of the shower. For 1 shower light it's irrelevant. The impossibility would be trying to get 2 10mm conductors into a shower switch or spur terminal. You could as you said use a 2 pole 100A connector block.
It's simply not good practice though.
PIR is a better option.

I'd be happy to be corrected if i'm wrong. I couldn't find anything specific in BS7671 either

 

[BOROROBBO]

all these ideas but how come you cant do the obvious..... use the existing lighting circuit as your supply?

 

[ukpablo]

Just get rid of the pull cord and run two separate ccts in bathroom to a double switch outside the bathroom. One operates the shower light and extractor fan and the other controls the other bathroom lights.......simple for u and customer gets what they want in a roundabout way!

 

[geoffa]

or fit a pull cord for the shower light next to pull cord for the shower and tie them together......