In article , John Rumm
wrote:
On 12/05/2021 18:19, newshound wrote:
I have two five amp lighting circuits, notionally upstairs and
downstairs but because of a funny house layout they overlap a bit.

I just put in a new stair light circuit and, for convenience, changed a
single gang light switch for a two gang one to cover the new circuit.
It was only afterwards that I realised that left me with one switch on
the "upstairs" circuit and one on the "downstairs", so you need to
throw two breakers to ensure that unit is dead.

While I am not going to lose any sleep over this, I guess it might not
be compliant with current regs, can anyone confirm? I have a relatively
ancient CU with all circuits protected by one RCD so it is fairly safe
against isolation failure.

You have exactly the same situation as any place with two way switching
of the hall and/or the landing light. So it's a common situation to have
two separate circuits at one switch position. So perfectly acceptable
from a regs point of view.

if they are both on the same phase?

--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle