Wiring an extractor fan

[V8OW]

This is probably a relatively straightforward question, but I'm trying to work out what's going on.

My electrician wired in some new lights in my bathroom, and did it so that I could add an extractor fan once I'd drilled a big enough hole! I've got what I presume is a fused isolator switch, but I'm not sure how it needs to be wired up to the extractor.

I'm not going to do it myself unless I know what I'm doing, but thought I'd see if someone could explain it to me.

Edit: the surface boxed is going to be replaced with a flush box!

Thanks

[Smiler.]

Middle terminal on the isolator (looks red) is the switched supply from the lighting circuit. This turns the fan on. The brown terminal (left) is permanent live for the run on timer.

I think.

[thebraketester]

The fan requires neutral, permanent live and a switched live. There are loads of diagrams on Google. I used one to do mine, it wasn't that tricky once you've got your head around it.

[V8OW]

Thanks - I'll try and see if I can make sense of some wiring diagrams!

[brman]

fan isolators are normally 3 pole. That looks like a 2 pole fused spur unit. Plus the isolated blue core is sleeved brown so is probably a live.
Not exactly standard then.

I think you are going to have to trace where those cables/cores are connected to before wiring that up.......

[PH5121]

It looks like you have a double pole switch or fused connection unit for your fan. What doesn't make sense to me is that you have a live conductor going into an outgoing terminal. You would be better off using a proper 3 pole fan isolator switch.

From your picture it looks like you may have the switched live cables connected into the in and out terminals, and the neutral at the switch, with the permanent live the blue conductor with the sleeving on it terminating in the connector block.

The switch has in and out terminals, the live out should have the cable that goes to your fan, not one of the incoming twin and earth cores at it.

As your fan has a timer you need the permanent feed, and at a push could connect from the connector block but for the sake of a few pounds I wouldn't. If you use a 3 pole isolator the supply to the fan is dead when the switch is turned off, rather than partly dead as you have the wrong isolation device.

You will need to double check what you have at the isolator switch as I suspect that you may have two switch wires into two seperate terminals at present.

[V8OW]

Strange... maybe I'll get my electrician back around to wire it up then!

The switch for the light is on the outside of the bathroom door (powers two led ceiling lights), and this box was fitted close to where I was planning to fit the extractor. I got the impression that once I'd got the extractor sorted it would be easy enough to connect up, but perhaps he was planning to do something else.

[brman]

V8OW said:

Strange... maybe I'll get my electrician back around to wire it up then!

I would, or at least ask him how he expects it to be wired