Strange security light wiring

[The Medway Handyman]

Came across a strange wiring set up on a security light I had to change today. Not seen it before & I change a lot of security lights - they seem dreadfully unreliable

Wired with 3 core + E cable, red, blue. yellow cores.

Old light was wired as follows;

Red - Brown to PIR. Blue - Blue to PIR & White to Lamp Yellow tagged "Warning Slave & Override (& something else obliterated) - White to PIR & White to Lamp.

Switch inside the house operated the light. It was in the On position.

Customer (a regular) had gone out, so I couldn't get into the house to check the switch (I could turn the circuit off in the garage).

Multi meter between the red & blue gave 230v & between red & yellow gave

230v.

The new light only had the facility to wire in L, N & E.

Wired up the new light using the red as L and the blue as N (blanked off the yellow) and all works exactly as it should, but I couldn't check the switch.

I'm assuming the old light was 'old' and didn't have the auto/manual feature found on 'modern' security lights, so had been wired with 3 core & E to allow it to be switched on permanently, overriding the PIR. The yellow seems as though it would achieve that.

Going back tomorrow for some more work, so I can re wire it if necessary.

Any thoughts?

[mick]

There's nothing too odd about this arrangement. It looks as if the PIR is a 3-wire one, with white being the switch output. Switching yellow to red bypasses the PIR contact to force the lamp on manually. What you have done will work fine, but doesn't have this remote override facility (at present, anyway!).

[cj]

Hi Dave Sounds like you got the right idea, the early lights had a 4 way connector block to facilitate bypass in fact MK made a switch to do just that being labelled AUTO / MAN

As you say brown is live Blue Neutral and yellow switched live BUT from your post you say you got 230v across brown & blue plus 230v across brown & yellow this suggests switched neutral which (although wrong) would work if wired differently.

Recommend you look at the switch in the house before trying to connect the yellow wire.

HTH

CJ

[Graham.]

Yes, but don't the recent ones latch on if you switch off and on quickly? isn't that what Dave meant by the auto/manual feature?

[The Medway Handyman]

Indeed they do, thats exactly what I meant. From the instructions; On/Off within 2 seconds by passes the PIR & leaves the light on all the time. Off/On greater tha 10 seconds resets the PIR.

[The Medway Handyman]

I blanked off the yellow with a chocky block.

[ARWadsworth]

You will probably need to swap the red and yellow cables (ie choc block the red) to allow for manual override and then leave the switch in the on position until an overide is needed.

The obliterated part of the label was probably a "max wattage for the slave" Adam

[Harry Bloomfield]

They stay on until the next dawn, then go back to normal PIR operation

- avoids you leaving them on 24/7.

[Harry Bloomfield]

The Medway Handyman brought next idea :

Put a choc block on the red to insulate it and use the yellow for the live. That way you can use the switch to disable the light, or a quick off plus back on forces it to stay on until the next dawn.