On 01/07/2018 09:29, ARW wrote:

I am trying to think of a way to simplify it.



Ways to simplify and keep down costs bearing in mind that it's an HMO
and no one of any importance will live there.

Lets assume that we are now going to put the lights and sockets in each
room on a shared 30mA supply.

1.Use a 5A unswitched fused spur in the room to power the lights from
the sockets. This saves space in your CU and will not be a problem.

2.This now means you just need 1 DP switched RCD in the CU for each
room, these can be DP or SP width depending on what you want to pay (the
Wylex SP width DP switching ones I linked to were about £26)

3.Use a hi integrity split load CU with a 100mA main switch.

4.Put the RCBOs on the 100mA side of the board (this will take 4 to 8
ways up of the CU).

5.Feed the room meters from the RCBO and then from the meter to each room.

6.Use the 30mA RCD protected spaces to power the communal areas


So if using Wylex stuff about £250.


--
Adam