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.

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.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 12/05/2021 18:26, 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.




I have 4 lighting circuits he

loft
1st floor
ground floor
outside lighting.

I have a double gang back box in the hall way with 5 switches on it. one
is for hall light, one is for landing light and these two switches are
on 2 different RCBOs. These two two watch switches are in the left half
of the double gang back box.

The right hand half of the back box has 3 switches for 3 outside lights
which is on a 3rd RCBO.

I have a mental partition in the middle of the double gang back box to
at least mechanically separate the outside lighting wiring from the two
indoor lighting circuits.

On 12/05/2021 18:26, 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.


I'm reassured. I've just realised I had the same situation in a previous
three floor house, where the middle landing had two way switches for
both the stairs going up and the stairs going down. It just seemed
counter to a "common sense" view that it's best to have a single
isolator for any wiring enclosure.

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

On Wednesday, 12 May 2021 at 19:41:04 UTC+1, charles wrote:

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?
I have seen three phases in one lighting switch box. It was a mechanical
workshop with fluorescent lighting and rotating machines.
There was a permanent warning label on the outside.
John

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.

If you have not "borrowed a neutral" this perfectly normal.

--
Adam