Outside light

[Loofah]

Can you wire an outside light with PIR and brown, blue and earth connections to existing wiring [from house] that has red, yellow, blue and earth?

 

[Taylortwocities]

It may be possible. But (as we aren't mind readers) can you reveal what is on the end of those red, yellow and blue conductors?

 

[Loofah]

That would be the old outside light which (obviously) has different wiring. GF bought it or her house wanting to replace like for like but this threw a spanner in the works so to speak.


<edit> Having re read your post, if you mean where do the wires originate then the CU. Its a new build house if that makes a difference and the CU is only a matter of metres away albeit inside the house.

 

[Steve]

Is there no switch that controls the light?

 

[ban-all-sheds]

If the new light had had 4 terminals or wires, e.g. brown, black, grey & earth, instead of 3 would that have meant no spanner?

You need to find out what each of your existing red/yellow/blue conductors does, by checking with a multimeter and/or tracing them backwards.

Unless the terminals in the old light are marked, and it is still connected or you made a note of what went where?

 

[Loofah]

The gf says there is but her dad bust it when he was trying to wire it all up... (he since gave up on the project) The switch has been replaced but I can't get any reading using a multimeter on the wires so I'm not convinced it controls the light.

 

[Loofah]

If the new light had had 4 terminals or wires, e.g. brown, black, grey & earth, instead of 3 would that have meant no spanner?

You need to find out what each of your existing red/yellow/blue conductors does, by checking with a multimeter and/or tracing them backwards.

Unless the terminals in the old light are marked, and it is still connected or you made a note of what went where?

Old light got binned and no-one thought to write down what went where. Unfortunately I've come to this a tad late! Not entirely sure how to trace back.

 

[Taylortwocities]

. Its a new build house if that makes a difference /quote]

Yes it does. Red/yellow blue cable is the old colours from 5 years ago and should not have been used on a new build house.

You are going to have to find the switch and then get a multimeter and tell us what of those three conductors are neutral and live and what the third wire does.

I would suggest blue is neutral and red is live, but you've got to find how to turn it on.....

 

[Loofah]

Will do next time I visit, thanks for help so far, much appreciated!

 

[Loofah]

OK, have tested the wires - red 240V, yellow 240V, blue 30V. I also measured between phases R-Y 0V, R-B 190V, Y-B 190V.

The switch I found appears to do nothing, same voltages found in either switch position.

Any thoughts?

 

[Steve]

OK, have tested the wires - red 240V, yellow 240V, blue 30V

With respect to what? Earth?

 

[Loofah]

OK, have tested the wires - red 240V, yellow 240V, blue 30V

With respect to what? Earth?

Sorry, yes, with respect to earth.

 

[Steve]

red and yellow are lives then. Connect them together.

Blue would appear to neutral, but goodness knows why its floating above earth potential. Do you have a TT earth supply (Earth rod)?

 

[Loofah]

So yellow and red into the live of the light, blue into the neutral.

Have no idea if the gf has TT earth supply, sorry.

 

[Loofah]

In case anyone else needs this for reference... it didn't work lol Could be that the light itself is broken as there's evidence of water ingress.

Thanks for helping guys

New light time!