FCU for bathroom fan in loft

Do not put a fuse in the neutral line.

Both live and switched live should be fused but you only use one fuse.

I like the idea of having a switch of some kind for any item that is in a loft myself. Brian

Who knows what I was thinking when I wrote that. Obviously I need to fuse L before it feeds switched L, unless I am magically going to find an FCU that contains two fuses.

Thanks to those who replied.

Depending on how you wire it a 3A switched FCU could act as a fan isolator.

Mine is a SFCU wired to a pull switch, so only the CU needed for isolation. I turn on the fan, give it a few seconds to start up, turn it off and it runs for ~25 min. The pull switch is 2-way as, when I get a tuit, I've a little timer that I can rig in to get around me forgetting to turn off the fan. The timer can be wired to be self-de-energising.

Does an FCU have the required 3mm contact spacing?

NT

Just look for one to BS 1363-4 (as even the cheapest seem to be)? (Was in Table 53.2 in the 17th. I can't justify buying the 18th.)

That table mentions BS3676: Pt 1 1989, BS EN 60669-2-4 and BS EN 60947-3 as being compliant.

NT

Is that after amendment? In my original the entry in Table 53.2 for a

Ah, seems I was looking in the wrong section, at switching devices. BS1363-4 it is. Bit surprised to see unswitched FCUs being acceptable too.

NT

Yes. It is purposed as an isolating device by design.

Having selected my fan (Soler & Pau Silent 100 CHZ 230V IP45) and installed it, I can find absolutely no mention in the manual of any fusing requirement! Might have got lucky here.

It's ONLY if the manufacturer says you have to...

True.

I have an S&P TD axial. I don't believe mine needs a 3A fuse - but the Manrose humidistat does(!!!) so I had to fuse it anyway.

But it will save me the bother in the shower room which will be conventionally coupled to the lighting...