Two Way Light Switching

[ColJack]

mind if I steal that for a sig?

well if you do, tough, I'm gonna anyway..

 

[ban-all-sheds]

top left one BAS..

Logically, yes, but not physically.

And ditto but flipped vertically for the hallway light...

I'm curious to know what sort of cable, or which core in what sort of cable, is used to take the switched live from the downstairs switch up into the 1st floor ceiling and to the light. And what route it takes.

 

[ColJack]

still a standard arrangement, how they got the switched live to the light itself is of no concern.. the "live in one switch, pair of strappers between and switched live out of the other switch" is very common, often refered to as two plate wiring..

 

[Space cat]

how they got the switched live to the light itself is of no concern

It's interesting though because I keep looking at this --

The downstairs one is fed from the downstairs MCB and the upstairs from the upstairs MCB.

Does that statement refer to the lights or just the switches? That old two-way circuit often conceals an insidious danger that our super safety conscious friend might not have considered, namely the borrowed neutral.

Erinues, when you switch off the downstairs MCB, which of the two lights no longer works?

mind if I steal that for a sig?

Be my guest, but you might like to check your spelling!

 

[ban-all-sheds]

still a standard arrangement, how they got the switched live to the light itself is of no concern.. the "live in one switch, pair of strappers between and switched live out of the other switch" is very common, often refered to as two plate wiring..

I realise that 2-plate, pair of strappers etc is very common, but in those cases all that runs between the two floors are the strappers, e.g. in the case of the switches for the landing light the permanent live goes to COM in the hallway switch, the strappers run to the landing switch and the switched live runs from there to the light. It's precisely because the permanent live originates downstairs that you can end up with a borrowed neutral when the circuits are later split between floors.

What erinues has is the permanent live going to the landing switch, the strappers running down to the hall switch and then the switched live running up from there.

In the traditional system there are two cores running between the floors, in his there are three.

Electrically it's the same, but physically it's not, and the physical aspect of the 3rd core is a concern - well, an interest anyway.

. . . Is it a single?
. . . Is it a sheathed single?
. . . Is it a single+earth?
. . . Is it one core in twin+earth?
. . . Is it one core of a 3C+E strapper?
. . . Does it follow the same route as the strappers, or a different one?
. . . Does it pass through the landing switch box?
. . . Does it get joined to something else inside the landing switch box?