Isolation for inline bathroom extractor fans. Where do others put the isolation switch for the fan ?? I know some people put a 3 pole switch above the bathroom door etc.. I was thinking about putting a switched fcu, fed off permanent feed off lights in loft next to fan, the fcu will feed a MF joint box. The joint box will feed a switch for fan in\outside bathroom, and a 3 core to fan. Surely this complies. I have been looking in regs, and can't see any reasons not to do it like this. Any thoughts ??

You are correct.The FCU can be put in the loft next to fan therefore complying with regs because all isolators are supposed to be within sight of person doing maintenance or if out of sight then they must be lockable type.
regards
Antric

I think this is a good way of doing it, in fact I done one just like this yesterday and have another to do on Saturday. The only disadvantage I can see is that when the fcu is switched off the bathroom light goes out as well. (you could also fit a 3 pole isolator just for the fan)
This does sort out the 3 amp fuse that some fan makers stipulate. The one I fitted yesterday was an Xpelair which didn't mention an fcu although it did show an in-line fuse on the instruction sheet but no mention of it in the text and also no amperage shown either although it did stipulate a DP switch, so I think the switched fcu works fine, DP switch and fuse,

Dave.,

Edited: 17 January 2013 at 11:50 AM by daveparry1

Why can't you use the mcb as Isolator, hows the in-line extractor any different from a light fitting. Its a load attached to the circuit.

You dont have isolators for each light

Manufacturers instructions Zeeper! (I agree unnecessary just like the 3 amp fuse even when connected to a 6 amp mcb)

Dave.

You do, usually, have a means for individually switching off for mechanical maintenance though.
- Andy.

I assume it all depends on what the isolator is intended for.
If it's for functional switching, then having it in the loft is not very practical.
If it's for maintenance, then fine, although is it strictly necessary (not actually aware of any Regulation requiring the point of isolation having to be within sight).
If it's for emergency switching, then again having it in the loft is not very practical, most likely wouldn't comply and the SFCU would have to comply with the requirements for emergency switches, I.e. the switch should be red.

For a loft fan i wouldn't even bother with the isolator. I use a 4-pole connector, ashley klik or similar, where i change from grey to flex.

The fcu is only fitted, because fan has to be down rated to 3amps. When fcu is switched off, it does not affect lights, as fcu is supplied from permanent feed off the lighting circuit. Outside the bathroom is a 2 gang switch, one for lights, one for fan. I hope this clears things up. What's the point of having extractor fan coming on with lights ? Bathroom has a window. If someone has a shower in the day, they won't want lights on as well, they can just turn fan on. The fan has a timer on it. I hope this is alright as I will be using it as part of my assessment, when I splash a shed load of cash and join a scheme.

What's the point of having extractor fan coming on with lights ?
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It is very common practice for the fan to come on with the lights and if it's a timer fan it needs either a 3 pole isolator or a switched fcu which isolates both the permanent live and the switched live, in this case it will isolate the light too!

The way I have wired it, when you switch the fcu off, it isolates the switched live and permanent live and neutral to fan. The lights will stay on as the fcu which feeds fan, via a joint box, is fed from the permanent live off the lighting circuit, not the switched live to the lights. That's why I have put a 2 gang light switch outside of bathroom. One to switch fan on, one to switch lights on.

That's ok if you want the fan to be able to operate independently of the light, no problem with that at all, in fact some customers want it that done way.

Yes that's right. When some people want the toilet in the middle of the night, they don't have to have the fan running and waking people up. I just wanted to make sure that this was acceptable for my assessment. 1, to have fcu in loft next to fan, and not above the bathroom door, and 2, having the fan switched on independently from the lights. Thanks for your advice.

i got picked up on this by a building inspector a few years ago, he said it was a requirement that the bathroom fan came on with the light.
i changed it then changed it back after he left at the request of the customer.

i have mine seperate at home for the reason you said, who wants the fan running at night if you get up to the toilet, especially in an en-suite.

It might have changed now because the building inspector didn't mention it, although i did flick both switches on together when he wanted to check the fan operation.

Gary

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Specialised Subject. The Bleedin Obvious. John Cleese

Write your o and m manual for the customer the way you have wired your lights.!

Hi

You can get fans with a selectable time delay so it wont come on straight away if your in the toilet in the middle of the night if linked to the lighting that is.

In a cottage last year I wired up an inline fan and as well as having a fan isolator outside the bathroom, I put one in the very accessible loft as well so that the occupants could be sure of isolation for cleaning etc.

Ok, a bit belt and braces, but what the heck for another few £? Everyone appreciates safety, especially if you point it out - I think.

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The meaning of life is a blank sheet; write on it wisely. ~ M.Cutler.

You can get fans with a selectable time delay
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I've never seen one with delay start CMD, only timed run-on,

Dave.

I always fit a fan isolator next to the inline fan in the loft and one above the Bathroom door for a wall mounted type.

Dave, most of the common extractor fan brands have models or bolt-on options for delayed start to allow for short visits. Some of the brands that do are: Vent-Axia, Airflow and Xpelair.

This is in addition to the timed run-on.

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M.I.E.T - Forfeited this due to The I.E.T's ridiculous membership rules!