Odd LED floodlight problem

[ImpededLoop]

A couple of months ago I installed two LED floodlights. One is 10W, the other is 30W. They are both connected to the same PIR and each light is no more than 400mm from the PIR.

Everything works when installed, but within a few days the 10W floodlight stops working. I've replaced it four times, most recently with a light from a different manufacturer. Within three days it's stopped working again.

I'm now intending to replace the 10W floodlight with one that has it's own PIR. However I'm curious to find out what the cause of the failures is. I must confess that I haven't tested any of the units that I assumed to have failed. There's definitely no wiring fault and the PIR and 30W floodlight have always worked perfectly.

Cheers.

 

[cliffed]

May be something to do with the low wattage of the led,playing up the electronics side of the pir.
Similar to the dimming of low wattage leds,producing flickering,due to leakage of current.

 

[Marvo]

Is the PIR output via a relay or is it solid state like Diac or Triac switched? Sometimes the solid state outputs don't play nicely with LED's or more specifically the electronics in the driver of the LED light.

 

[ImpededLoop]

May be something to do with the low wattage of the led,playing up the electronics side of the pir.
Similar to the dimming of low wattage leds,producing flickering,due to leakage of current.

The PIR is working as it should though, as is the 30W floodlight.

 

[ImpededLoop]

Is the PIR output via a relay or is it solid state like Diac or Triac switched? Sometimes the solid state outputs don't play nicely with LED's or more specifically the electronics in the driver of the LED light.

I'm pretty sure it's a relay as I think the PIR makes an audible click noise when it activates. I will double check though, thank you.

 

[HandySparks]

Is the 10W light subject to some influence that isn't affecting the 30W light? Vibration, heat from a boiler flue, impact from a door/window/whatever???

 

[ImpededLoop]

Is the 10W light subject to some influence that isn't affecting the 30W light? Vibration, heat from a boiler flue, impact from a door/window/whatever???

No, there's nothing like that which would affect one and not the other.

My only thought is that it could be something to do with inrush current, but I can't back it up with any facts!

 

[dmxtothemax]

My best guess would be that it is too small of a load, and the electronic switch in the PIR is having trouble because of that. Just like some dimers need a minimum load to work correctly, so to does this electronic switch in the PIR.

 

[ImpededLoop]

My best guess would be that it is too small of a load, and the electronic switch in the PIR is having trouble because of that. Just like some dimers need a minimum load to work correctly, so to does this electronic switch in the PIR.

No, the PIR is working fine as the 30W floodlight works as it should from the same PIR.

 

[dmxtothemax]

I think you have missed my point !
The 30w light works fine because it is a larger load !
But the 10w light is a much smaller load, and that is the problem !
Small loads don't always work well off some electronic switchs.

 

[ImpededLoop]

I think you have missed my point !
The 30w light works fine because it is a larger load !
But the 10w light is a much smaller load, and that is the problem !
Small loads don't always work well off some electronic switchs.

If the 10W floodlight was the only one on the PIR then I would suspect that too. When I return to replace the (possibly) defective floodlight I'll test it to see if it works. If it does, your suggestion could well be right.

 

[GeorgeCooke]

I think you have missed my point !
The 30w light works fine because it is a larger load !
But the 10w light is a much smaller load, and that is the problem !
Small loads don't always work well off some electronic switchs.

But it is not an electronic switch. He has already said he can hear the relay click.

 

[Electrical2go]

What's the make and model of the PIR?

 

[ImpededLoop]

Just to follow this up, I visited the job again and found that the 10W LED floodlight had indeed failed and didn't work when connected to a 230V supply.

The PIR definately has a relay, is rated upto 1200W (I know LED's will have a high inrush current) and is still switching the 30W floodlight with no problems.

My gut feeling is the cause of the problem was something to do with the 30W and 10W floodlights being wired in parallel from the same PIR and therefore energising at exactly the same time; somehow damaging the 10W floodlight, on each occasion, within days of installation.

I've now installed a 10W floodlight with it's own PIR and am confident that the problem won't now reoccur!

Thanks to everyone who replied.

 

[ImpededLoop]

What's the make and model of the PIR?

It's a Zinc 360 deg corner mount from Toolstation - I know I should have bought one at the wholesalers....