On Mon, 6 May 2019 15:43:49 +0100, Chris Green wrote:

ARW wrote:
On 06/05/2019 13:04, Tricky Dicky wrote:
Most fan isolator switches for bathrooms and WC are positioned outside
the room above the entrance doorway. As far as I can see you only need
to provide isolation for the fan the rest I would suggest is wired directly
into the lighting circuit you describe. I do not know how you intend to
create the cubicle but presume it will be a studded structure with a wall
and doorway at right angles to each other. If so you should be able to
wire in the isolator switch during its construction.

They were usually placed outside because of misread 16th edition regs.

The OP is probably going to need RCBOs to meet the 18th edition regs.

Ah, a good point, this is I guess an addition rather than a
replacement so I need to conform to 18th edition. I should be able to
replace the existing 6A MCB with an RCBO I think, just need to check
the space in the CU.

From not-very-accurate measuring, it looks as if a miniature RCBO will
replace an MCB. My board is a Wylex from about 1990 and a Wylex mini-RCBO
seems to be OK.
--
Peter.
The gods will stay away
whilst religions hold sway