Light fitting switch cable - quick identify?

[TonyWarrington]

Nearly caused myself a problem the other day when replacing ceiling rose for several new light fittings. Usually I mark the switch cable with tape but on this occasion I was disturbed and on returning to the job took a little while to figure out where I left it. Anyway all ok - however it did make me think what is the best way to identify the switch cable - what would the pros do (apart from not making such a basic mistake in the first place).

I can think of the following. All with power disconnected:

1. Multimeter test on each cable to check for switch circuit (assuming one to hand!)

2. Battery and torch bulb across cable.

Is there a better / easier way - any problems with the above methods

Thanks Tony

 

[luminaire]

With power switched off at CU. Join tgether the two wires at the switch from C and L1. Do a continuity check at the ceiling rose with a continuity checker (or DMM).
Usually the switch wire is black. This would then be sleeved in brown.
Replace wires.

 

[TonyWarrington]

Thanks for the tip - my suggested method would have been quite long winded compared to your more elegant solution.

Cheers
Tony

 

[ricicle]

Usually the switch wire is black. This would then be sleeved in brown.
Replace wires.

Why sleeve in brown? If it is black then there's a good chance that the permanant live is red so I would sleeve it red as it is an existing installation

 

[securespark]

With power switched off at CU. Join tgether the two wires at the switch from C and L1. Do a continuity check at the ceiling rose with a continuity checker (or DMM).
Usually the switch wire is black. This would then be sleeved in brown.
Replace wires.

Why short them together?? Just close the switch!

 

[dingbat]

Why short them together?? Just close the switch!

D'oh! Beat me to it!