security light false triggering

Discussion in 'Electricians' Talk' started by james_15, Nov 6, 2014.

  1. james_15

    james_15 New Member

    Hi, hope someone can help us with out security light. We're really at our wits' end with it.
    It keeps coming on for no apparent reason. First thing I did was to check for anything moving, but couldn't see anything. There was absolutely no wind that night, everything was completely still. We considered the possibility of the nearby boiler flue being the cause, but it often triggers when the boiler is off. So we tried covering the left side of the sensor. The problem continued, leading us to believe it was picking something up on the right. So then I tried covering the right side of the sensor, but the problem still continued. I also tried covering up the nearby water butt, as I have heard that pools of water can cause false triggering. Again, no change. Next I wondered about electrical interference or a fault with the sensor, so covered the entire sensor. This time the false triggers stopped. So I think we can safely assume that the sensor is definitely seeing something, but the question is what? I've also now adjusted the light position as there was some heat radiating from the bulb towards the sensor, and covered the top half of the sensor, which covers long range detection. Last night this seemed to have cured the problem, but tonight it has returned. So now we're pretty much out of ideas. Has anyone got any other suggestions?
  2. seneca

    seneca Screwfix Select

    Sounds like you've had a good try at solving it James, i'd say try replacing it now, they're not very expensive these days.
    FatHands likes this.
  3. james_15

    james_15 New Member

    I'm beginning to think that way myself. What bugs me is the fact that covering the sensor stops it triggering, so there must be something that it's picking up. There's nothing I hate more than an unsolved mystery. But yes, we are seriously considering replacing it, probably with one that has adjustable sensitivity (which this one doesn't) so if it keeps picking something up we can turn the sensitivity down a bit.
  4. Phil the Paver

    Phil the Paver Screwfix Select

    Insects, spider maybe, inside the sensor that you can't see, but is triggering it somehow.
  5. Phil the Paver

    Phil the Paver Screwfix Select

  6. unphased

    unphased Screwfix Select

    Go for a 30W LED then. Pointless buying these halogen lamps now as they use too much electricity. This laughable energy saving they claim on a 400W is ludicrous.
  7. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    Yeah. Moths.

    Mr. HandyAndy - Really
  8. mof

    mof Member

    Most probably will be rf getting to sensor is there a regular taxi firm or police car nearby or radio ham or a CB station? these security lights are poorly screened its not the fault of the transmitter if that is what is causing it to come on.
  9. Mr. Handyandy

    Mr. Handyandy Screwfix Select


    I mentioned moths......and a mof appeared!

    Mr. HandyAndy - Really
    FatHands likes this.
  10. FatHands

    FatHands Well-Known Member

  11. james_15

    james_15 New Member

    Hmm...there's a local radio station a couple of streets away, but probably a bit too far to be the cause (about 500m as the crow flies). We do have a wireless weatherstation, so I guess that's a distinct possibility. Still doesn't explain why covering the sensor seemed to stop it, but I guess that could have been a coincidence. Definitely wouldn't be surprised if it's poorly screened, I think it was only about £20 so not exactly upmarket. I thought it was mostly fine over the summer but maybe we're just noticing it more now as it's getting dark earlier. So yes, sounds like it's time for a decent quality replacement. We're definitely thinking LED - that way even if it does keep coming on it's not wasting loads of electricity.
    Thanks for the suggestions.
  12. Mosaix

    Mosaix Active Member

  13. Corkboy12

    Corkboy12 New Member

    Is the light taken off a switch that has other light circuits on it? i.e 2 gang switch with one being for outside light on pir and second inside light. If so it may be when you are switching the other switch, even at another switch if 2 way the switch sometime break the circuit for a split second to all (cheaper switches) and it is enough to turn on an off the pir light which initiates a false trigger. I know this issue was some time ago but would be interested to hear if there was ever a solution
  14. james_15

    james_15 New Member

    Yes, it is on a 2-gang switch shared with an internal light, but as far as I can remember that wasn't triggering it either. The simple answer is, the light was knackered. Replaced it with a new 22w LED one and haven't had any problems since. Occasionally the boiler triggers it but even that is rare, for the most part it only comes on when we want it to.
    Corkboy12 likes this.
  15. pra

    pra New Member

    With an old light, we had the opposite - but it was sensitive to light AND movement. The sensor was in a little tube and a bee used to make it its home for the day, making the sensor think that it was night all 24 hours. It was uncanny to walk up in bright sun, and the light would suddenly come on. Used to have to tweek it out - I don't know if it was the same one kept coming back

    Now I have the night-time wind problem. I'll try some of your solutions. But simplest of all would be to switch it off - but I can't find the switch !
  16. Peter208

    Peter208 Active Member

    Couple of years back, our Pir controlled lights either side of the garage would come during the night for no reason.
    Took a bit of time to workout why. It as a small bird settling down for the night that tripped the sensor .
    Just seen, this is an old post 2014

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