Bathroom extractor problem

[Joecobbs]

Hi,

I've had a look at other extractor wiring problems and nothing comes up like this problem.

I've wired up a timed extractor (and isolator) using three core and earth into the junction box of the lighting circuit. Everything works fine except the fan turns on when the light is off and turns off(after the minute over run) when the light is turned on.

It's probably an easy fix but I can't see why this is happening?

Thanks

 

[Taylortwocities]

My guess is that the neutral wire is not really connected to neutral.

How did you determine which connection was what in your "junction box".??

 

[Joecobbs]

Thanks for the reply.

I connected the live/brown to the four live/Browns, the neutral/grey to the four neutrals/blues and the black to the brown-blue switch live.

 

[EFLImpudence]

Are you sure you did the same at the fan?

 

[Joecobbs]

Yeah, switch live in l1, perm live l2 and neutral in N in the isolator, then matched the correct wires to the labels in the fan.

Sure I must have missed something obvious but can't figure out what?

 

[EFLImpudence]

Is it an incandescent filament bulb?

What does it do with the bulb removed.

 

[Taylortwocities]

Do you have a multimeter, or a two probe voltage tester to check that what you have at the JB & fan are what you think you have...

 

[Joecobbs]

Is it an incandescent filament bulb?

What does it do with the bulb removed.

Just checked and without the bulb in the fan doesn't come on at all

 

[JohnW2]

What does it do with the bulb removed.

Just checked and without the bulb in the fan doesn't come on at all

As we suspected. It sounds very much as if TTC was right at the start, in saying that what you thought was a neutral at the junction box is not actually a neutral. A photo of the wiring inside that JB might possibly help us.

Kind Regards, John