Lighting Circuits

[Paul505]

Maybe a bit of a silly question but im interested in what you would do......
2 gang switch situated in the hallway at the bottom of the stairs, 1x switch operates light in downstairs hallway off the downstairs lighting circuit and the other switch is the 2 way switch operating the upstairs landing light off the upstairs lighting circuit.
Would you join the 2 x cpc's together or leave the one from the 3-core disconnected so as not to join the two circuit cpc's together ?

 

[Mark_Burgess]

Both CPC's should be connected to the box, individually sleeved.

All CPC's go back to one common point in the consumer unit, then to earth.
It's neutral conductors that you don't want joined (borrowed) as they may well be on different RCD's or RCBO's, its this that will give nuisance tripping.

 

[Plonker 3]

^^^^^ Agreed, also this method provides a extra earth to the circuits should one of them get disconnected or break off.

 

[Paul505]

Thanks for the replies chaps......
I have always connected both cpc's but have seen the 3-core cpc cut off from the upstairs circuit at the downstairs end....

 

[Paul505]

^^^^^ Agreed, also this method provides a extra earth to the circuits should one of them get disconnected or break off.

The only thing is you would never know if you had a problem with a broken cpc on the other circuit, but at least you would be providing earth protection to that circuit through the switch cpc connection which is better than nothing. Then hopefully the earth fault would be picked up at some point.....