3 pole fan isolation

[Chri5]

I've fitted these as standard of a few years now.

Are they absolutely necessary?

I know they allow for service / remedial works to a fan via local isolation, but isolation at the board does the same thing (even if it does kill the entire lighting circuit).

I've had a few customers who have been rather upset when they discover the unit fixed above the door frames outside the bathroom.

Could someone offer a 16th / 17th ref that I can throw back to the winging masses.

 

[Spark123]

The manufacturers instructions (MI) say one needs to be fitted
Along with RCD protection (BS7671:2008) and quite often the MI also requires a 3A fuse. It is a fundamental requirement of the 17th ed that the MIs are followed.

 

[Click-Sure]

What if the kitchen/bathroom has no windows?

I'd not like to service a fan in the dark!

*OK, I'm a spark and carry a loft-light and torches but fan maintainence guys generally don't.

Besides - Best-Practice.