Replacing an old Light-Switching Sensor for External Light Ask questions and find answers to many subjects relating to electrics and electrical work

[regmay]

Hi there, I'm replacing an old dilapidated sensor for switching lights on at the side of my house and was intending to do a like-for-like rewire. There's a single cable running to the sensor - I believe it's called Multi Core Circular ( 4 core - Brown, Black, Blue, Yellow/Green). The wiring is as follows:-

SENSOR CABLE
Brown Brown
Red Blue
Blue Black and Yellow/Green

What's thrown me is that the Yellow/Green wire (in the cable) which I associate with Earthing is wired with the Black to the Blue in the sensor. Would really appreciate opinion on whether this is correct and safe.

[Mr White]

It is not the normal thing to do, and as such could easily be mistaken for what it appears to be, earth.

[regmay]

That's what I thought. Any idea why it's been wired like this ?

[Mr White]

For the definitive answer to that you would have to ask the person who wired it, but since that is not going to happen, all anyone can do is to speculate but in this instance, it would be a waste of time since we can never know the actual answer.

[regmay]

Thanks for replying.