Light Switch/Fan configuration in bathroom

[richardjh79]

Hi everyone, hope someone can advise - i have some electrical experience but lighting and switching circuits not my forte

I have an old extractor fitted in my bathroom ceiling - no motor in visible in the bathroom this is attached to a flexi-tube up out into my soffit.

The fan packed up some months back and just make a gentle whirring noise now and doesn't extract the steam (where before was very powerful and much more noisy)

So i knew the fan needed replacing and i have just had to have my fascias and soffits all replaced so was expecting to see the motor end there - but it was not?? so no motor in bathroom no motor in soffit, only other possibility must be 'in line' type rotor fan god knows where boxed in the loft room cavity (all boarded up now!!)

So I thought i would take half the panelling off the ceiling and wire new extractor into t he light switch so when the pull cord is pulled it switches on/off etc... on no that would be too easy, the bloody pull switch is 240v off 0v on??? now excuse me but wtf - i hate lighting circuits.. HELP

 

[bernardgreen]

the bloody pull switch is 240v off 0v on???

If you have the meter probes across the switch, ( Live and Switched Live ) then what you are reading is correct.

When ON the switch is closed and the probes are connected to each other via the switch. Hence no voltage

When OFF one probe is connected to Live and the other probe is connected to Neutral via the lamp. Hence with a few micro amps through the lamp to feed the meter the meter reads 240 volts and the lamp doesn't light.

 

[Taylortwocities]

To replace the fan, you will need live, neutral and switched live.

They will all be conveniently situated and connected to your existing fan.
I hate builders (and others) that do this sort of thing. Sounds like a part of the ceiling might need to go, so you can get access.
Don't forget to fit an access hatch when you've done.

 

[sparkwright]

The light switch very likely only contains live and switched live - no neutral.

While you can have a manual fan to come on and off with the light ONLY, it is usual to have a timed fan that comes on with the light, then when light is turned off fan with run for a few minutes then go off.

Or you could have a manual fan that is controlled by it's own switch.

You could even have a timed fan controlled by it's own switch somewhere, that will still over run for a few minutes, though not many people seem to have that, for some reason.

You may need a 12 volt 'low voltage' (wait for it) fan if it's too near the bath or shower. That would involve situating a fan transformer somewhere out of the way but accessible.