Bathroom extractor fan problem

skitler

now where getting somewhere.


the cable will then be a 3 core, + earth


brown, black and grey, earth should be sleeved green/yellow


that cable should be re couloured


brown, brown, and blue.


however if you swap the live and sw live over in the connections at the fan and leave the neutral alone, that should rectify the matter. failing that you will need it look at.


it should work as thus


when light is switched on the fan comes on and stay on as long as the light is still on, when you switch off the light the fan should stay on for aprox 15 mins and then go off till light is switched on again.


there is a small timer near the fan connections that is adjustable with a flat screwdriver to increase or decrease the time the fan stays on after light has been switched off

Ruski

Why would swapping the lives make a difference? The issue isn't that the 'timer' function doesn't work, it is that the fan shuts off after half an hour when the light (s/l) is still active...

Unless I've misread the diagnosis.. which is more than possible

Russ

Ruski

Does it have a humidistat function? This may be a cause?

Russ

cyclonebri1

The OP only has to wires running to the fan, at least only 2 they can see. I'd suspect a permanent feed has been taken separately from elsewhere, linked into the ceiling rose for eg. Does sound like these wires are reversed.

aetbaar

Risk You are correct the fan switches off after half an hour even with the light on and no it does not have a humidistat just a timer

I am sure the wires are taken from the circuit feeding the ceiling spot lights as there are only two wires - as suggested I will swap the wires around

If there are only two wires should they go in live and neutral or switched lived and neutral they are currently in live and neutral

Ruski

I very much doubt that swapping the wire around will make a difference, and certainly using SL instead of L would doubtfully work either.
Identify the exact model of fan and get the manufacturers inctructions - modern energy efficient fans may well have a 'max on' factory setting in order to conserve energy.....

HTH

Russ

skitler

well this is more info


if you only have 2 wires then swapping them wont make any difference.


in post 11 you say it has 3 wires.


the neutral needs to stay where it is


put the sw live in its correct terminal and then put a link from there to the other live terminal.


that will solve the problem


however you will not have a over run. ie light on fan on, light off fan will go off.


essentially it works but its wired wrong and not to building regs.

Ruski

Bit ambiguous in #11 - three terminals, two wires is what is meant

+1 for above solution tho.

Russ

cyclonebri1

Wonder if the neutral is actually there and the wires are live and switched live.

I know I know that should not work but if there is some sort of return through wherever it was fed from then............. Straw clutching of course;);)

aetbaar

Thanks all

So as per skitlers recommendation I should have the two wires in neutral and live then a separate bit of wire joining neutral and switched live ?

If that is right I will try it and report back

Thanks again