Two 2way light circuits.

[EFLImpudence]

The two latter in isolation are, but together they have one cable containing the line for one light and the switched live for another light - twice - which is why I thought Rocky was concerned.

Whilst this may not be revolutionary, it is surely not the usual way of doing it and as such cannot be plumb-standard.

 

[JohnW2]

The two latter in isolation are, but together they have one cable containing the line for one light and the switched live for another light - twice - which is why I thought Rocky was concerned.

I don't really understand that.

If light A is 'on', one core of the relevant strapper cable will be carrying the S/L to that light (A), whilst the other core will not be connected to anything at ether end.

If light A is 'off', one core of the relevant strapper cable will be connected to L at one end and the other core will be connected to the light (A) at the other end, but neither of those cores will be connected to anything at t'other end. That is no different from simple 1-way switching, and the only 'risk' is that if the cable is very long, capacitive coupling between the L and 'lamp feed' ('S/L' if you like) might be enough to make an LED (in light A) flicker.

... and the same for light B.

I see no circumstances in which I see any scope for one light's 'circuit' to affect the other (unless it's simply a matter of two cables being in proximity, but that's always a theoretical 'risk'). Am I missing something?

Kind Regards, John