Floodlight PIR has red blue and black wires

[fifejim]

Hi folks, to cut a long story short, I took a PIR sensor from an old halogen floodlight and fitted it to another of the same wattage. Stupidly I didn't note down what colours connected to what on the original and hoped you guys may know. Please see photo. I'm guessing blue connects to neutral, red to incoming live and black is the switched live?
Thanks!

 

[mikehammer69]

yes, more than likely

halogen goes to blue and black

 

[Adam_151]

It could be manufacturer dependant..... I would have personally thought that with those colours it would be more likely for the black to be neutral and the blue to be the switched live.

I expect that if you got your multimeter on one of the higher resistance ranges, you'd get a reading between live supply and neutral conductors (thus you know know which is the switched output), you'd then have to carefully power it up on the bench to be absoletely sure which one of the supply conductors is live and neutral (you want a switched live... NEVER a swicthed neutral) You'd hope that the red was the live, but you cant assume anything

 

[ban-all-sheds]

I'm guessing

Guess away.

What could possibly go wrong?

 

[fifejim]

Guess away.

What could possibly go wrong?

I probably should have said 'assuming' rather than use the Americanism 'guessing'!

 

[fifejim]

It could be manufacturer dependant..... I would have personally thought that with those colours it would be more likely for the black to be neutral and the blue to be the switched live.

I expect that if you got your multimeter on one of the higher resistance ranges, you'd get a reading between live supply and neutral conductors (thus you know know which is the switched output), you'd then have to carefully power it up on the bench to be absoletely sure which one of the supply conductors is live and neutral (you want a switched live... NEVER a swicthed neutral) You'd hope that the red was the live, but you cant assume anything

Good point Adam. Between red and blue I get a solid 15M on the multimeter 2000Mohm range (funnily enough no reading using the 20M range). Between red and black on the 2000M range get a high reading that increases to an open circuit reading. Same between blue and black. Does this suggest red and blue are live and neutral do you think? Thanks.

 

[ban-all-sheds]

I probably should have said 'assuming' rather than use the Americanism 'guessing'!

Assume away.

What could possibly go wrong?

 

[Doggit]

I take it there are no manufacturing labels on the unit.

 

[333rocky333]

Does the thing come apart, its more likely marked on the printed circuit
Are you sure the "Black is not actually "Brown"

 

[fifejim]

I take it there are no manufacturing labels on the unit.

Hi Doggit, thanks for response, nothing on the PIR itself. The overall light is a Synapse 5000, (as in this link http://www.newandused.co.uk/media/c...f78eab33525d08d6e5fb8d27136e95/1/7/1795_3.JPG)

 

[fifejim]

Does the thing come apart, its more likely marked on the printed circuit
Are you sure the "Black is not actually "Brown"

Hi rocky, thanks, definitely black unfortunately. Maybe because they've rusted, but I cant make out if the recessed sensor cover screws are very small crosshead or torx even after trying all sorts of driver types so havent been able to get into it. Even with a small flat screwdriver blade I can barely feel an 'edge' within the screw-head.

 

[ban-all-sheds]

And a new PIR from a quality maker such as Steinel is how much?

 

[SUNRAY]

I've have had a look at 3 units and they are red, black & white or brown, blue & white L, N & SL.
On that basis my guess is red, black & blue as L, N, & SL to test it I'd wire it that way but to protect it, wire the 500w lamp in series with red and a 60ish W lamp as the load across blue and black.

 

[fifejim]

I've have had a look at 3 units and they are red, black & white or brown, blue & white L, N & SL.
On that basis my guess is red, black & blue as L, N, & SL to test it I'd wire it that way but to protect it, wire the 500w lamp in series with red and a 60ish W lamp as the load across blue and black.

Hi Sunray, would that then prove red, black & blue is L, N, & SL respectively? Thanks.

 

[fifejim]

And a new PIR from a quality maker such as Steinel is how much?

They seem to be from around £23 upwards, as much as some entire new PIR lights, but anyway cant see any that can be used to replace an existing PIR that's part of a floodlight. They all seem to be stand alone.