Shower light/extractor fan wiring

[stuart2979]

I have installed a new shower cubicle with it,s own light. This light is low voltage and also links iinto an extractor fan supplied with the light. I have wired the light by daisy chaining off one of the spot lights in the bathroom. Where is the best place to get the power for the fan so that it comes on when the light does. I understand the fan needs to work off a switched live. Can this be taken from the light switch???

 

[nstreet]

Are your spots lv then? If so, can the transformer cope with another addition to the circuit and are they the same voltage?

 

[stuart2979]

The spotlights are 240v there are 3 in total. I have wired off the last light into the mains feed 240v of the transformer for the shower light.

 

[mapj1]

It is normal to take power for the fan from the lighting circuit, ideally via an isolator switch, so the fan can be disabled for cleaning/repair without having to turn off all the lights on that floor. If the fan has timer run-on (keeps going for a minute after the light) thn you take a steady live and a switched live either from the switch or the cieling rose/joint box in the ceiling, depending how the original wriring is arranged. Beware that the 'black' from the light switch is usually not a neutral, but a switched live (i.e. live when switch is in, off otherwise), strictly should be marked as such with a red sleeve or tape tagging, but often is not. Much fun arises if you assume this wire is a neutral, and place the switch straight accross the supply.
There are some sketches in 'For reference' section at the top of the BB, for just this sort of thing.
regards M.