Outside lights, on new built house

[OJ]

I want to fit 2 outside PIR lights - the builders have left 2 sealed electrical points on the back wall of the property. Each contains a 4-point jointing block - the usual 3 core, plus a grey wire with a bit of brown sheath on it.

Can anyone tell me what this 4th wire is for? There are 2 switches in the house - could this be related?

OJ.

 

[oharaf]

Sounds to me as if they may have set it up so that you can activate both lights via either PIR, the brown sheathed grey wire indicates it is live


Two switches would indicate they are independantly controlled

 

[Steve]

Theres a couple of ways it could have been wired.

1. One switch controls both lights to work on PIR, the other switch overrides the PIRs. The wiring would also mean that both PIRS switch both lights. If this is the case, I'd change the switch for a keyswitch and normal switch combo so you can easily differentiate the two switches.


2. The two switches control the two lights independantly. The only way to find is to use a multimeter and test for voltage on different switch positions, or investigate the wiring at the switch.