Shower circuit and extractor fan kit ?

[majorj0nny]

Hi -

We have installed an electric shower (or are about to), a 10K one.. and are due to get an electrician in to sort out our consumer unit so its able to provide a seperate supply (ring?) for the shower from a suitable MCB.

I think we can sort out getting a suitable supply into the loft dirext from the fuse box, to supply the shower, and I have a suitable pull cord isolator switch (like a cooker switch on a cord - with neon light and on/off) So Im ok with wiring all that in ..

however - I also want to add an extractor kit which comprises of a fan, dusking and low voltage light that runs off a transformer...

can I wire this kit onto the same supply the shower uses ? my idea was when I switch the shower on with the pull cord - the light and extractor will also come on - but how does this effect the large load the shower pulls? is this pretty standard a thing to do or should the extractor run off a 'lesser' circuit in the house and obviously be switched using a different switch ?

 

[alphaalarms]

taking that you have a 10mm cable suppying the shower!
you can ad the fan and lights using a fuse spmp with a fuse rated 5apm!

 

[Steve]

you can ad the fan and lights using a fuse spmp with a fuse rated 5apm!

Whatever that means, no he cant.

Run it on the lighting circuit. Tie the fans pull cord to the shower's pull cord if you want.

 

[saxondale]

Just leave it for the sparky to install - cheaper and legal

 

[majorj0nny]

taking that you have a 10mm cable suppying the shower!
you can ad the fan and lights using a fuse spmp with a fuse rated 5apm!

Im not understanding what you are trying to say there - I will have a 10mm cable once the electrician sorts that out - i will just ask him what to do, since everyone I know with a shower, their extractor fan turns on via the main shower isolator.

anyway - as for tying 2 cords together - i want my bathroom to look nice, id rather than a whole other switch somewhere else if I have to.

and as for an electrician being cheaper and legal .... faster/easier and legal Im sure he will be ... but cheaper? unless he doesnt charge labour I seriously doubt its going to be cheaper.

 

[RF Lighting]

But your LABC registration fee will be £150 - £300, which your electrcian does not need to pay.

 

[DESL]

since everyone I know with a shower, their extractor fan turns on via the main shower isolator.

Most unusual!!

 

[Lectrician]

VERY unusual - I have done it once, and it involved a small 2 way consumer unit with two MCB's after the pull cord, and I still consider it a bodge.

How about a humidistat? Fan comes on when it gets steamy.......the light comes on with the usual centre light.

In some commercial apps with many showers, it is common to fit a flow switch to the pipework feeding the showers, and have this power a fan with run on timer.

Out of interest, have you bought cable? If so, what size? What make switch is it you have bought? Are you aware of the requirements for supplementary equipotential bonding in a shower/bathroom? Are you aware of your legal requirements in regards the building regs part-p? (you must notify building control if you intend to do this work).

 

[Lectrician]

Oh - and as for tying the pull cords........Twas a joke I hOpe

 

[saxondale]

and as for an electrician being cheaper and legal .... faster/easier and legal Im sure he will be ... but cheaper? unless he doesnt charge labour I seriously doubt its going to be cheaper.

nah your missing the point - put it bluntly you cannot just do this work, you tell me ? what forms have you filled in so far

 

[daytona]

thats well wonky mate(original post).
run the light and fan off the lights and leave the shower on its own cct.
a 40amp protected light and fan would never make its way onto one of my certs.

 

[daytona]

dont think you could get a 10mm in the terminals of a spur if you tried to fuse it down somehow.as said before its wonky,dont do it

 

[majorj0nny]

thanks for the replies all - seeing as we needed not to cheap out on this and do a good job , I have now got an electrician in, hes installed a new consumer unit with RCD and MCBs with a new ring for the shower using 10mm cable up into the loft.

the extractor has been wired to the lighting circuit in the bathroom too...

hes certified it all too and done a load of earthing work on the rest of the house as well as the necessary socket, switch, and light checks.

Cost quite a bit - but atleast its a good job done correctly.

 

[ban-all-sheds]

VERY unusual - I have done it once, and it involved a small 2 way consumer unit with two MCB's after the pull cord, and I still consider it a bodge.

Then you shouldn't have done it

It actually can be done, quite safely - it's an unusual solution, but not a bodge:

//www.diynot.com/forums/viewtopic.php?p=123601#123601

works a treat.

Or another idea is to fit a flow-switch on the shower water supply, and use that to trigger the fan.

 

[RF Lighting]

Could you not use some sort of CT arrangement to switch a contactor when the shower draws a load, removing the need to use the shower switch to turn the fan on and off?

<edit> Just seen your flow switch idea. That would be much more sensible