PIR troubles

[F]

Since I installed a CCTV camera above a PIR (the only one on the Entry zone) the alarm refuses to set. It sounds the usual setting tone and then the Entry zone LED comes on and it alarms.

Could there be a problem with the two being in close proximity to each other, or could I have got some dust inside the PIR when I drilled the ceiling (despite having the vacuum cleaner nozzle up against the hole as it was being drilled)?

Unfortunately, I can't see how to get into the PIR to give it a clean out: there's no screws visible so I presume it needs to be prised open. Before I try, does anyone recognise it and know where to lever it open, or where the screw(s) might be?

Image at

[Chris Hogg]

No idea if this will solve the problem, but you could try temporarily screening the PIR from the camera. Simply a horizontal piece of cardboard cut to fit in the corner and taped into place. Or a sheet of metal similarly positioned to give a bit of rf shielding. If either make a difference, it'll give you some idea as to what's causing the problem.

[Steve Walker]

Maybe an RFI problem with the camera being so close.

Is the camera wired or wireless, that could make a difference?

SteveW

[tabbypurr]

PIRs respond to changes in IR, so dust in the unit won't trigger it.

Might be RFI.

NT

[GB]

We had one that had to be cleaned out because of a spider.

[Martin Brown]

Spiders certainly do trigger it if there are any warm spots in the room.

Vibration from drilling a wall might have made one of the connectors come loose. Switching the camera off completely would be one test.

Beware of antitamper measures on the PIR detectors - you may need to put the alarm controller into engineering mode before taking one apart unless you really want to be deafened.

[Mike Tomlinson]

En el artículo , F escribió:

Spot the connection. You've drilled through the PIR cable?

[F]

No, thank goodness, the two cables take completely different routes.

[F]

Wireless.

[F]

Why didn't I think of that earlier? I'll give that a try.

I can get use Engineer Mode but I don't know how to open the PIR. There's a small slot and pinhole underneath but no other obvious way in.

[whisky-dave]

If those are IR LEDs in the camera unit they could be giving false or triggering signals to the PIR.

[Martin Brown]

Mine have a clip on thin screen in front of the sensor that springs out when you do exactly the right thing to the catches. It is thin and rather fragile so forcing it not a good idea. If you can find the exact same model online then the manual should say how to open it.

Once in you should see the mounting screws and cable block connectors.

My guess would be a small screwdriver in the slot and a bit of gentle persuasion since that is pretty much how mine come apart. Good luck.

[F]

Thanks, but the problem is there when they're not lit.

[F]

I've tried it now and it makes no difference. What I have noticed, and I don't think it was there before, is that as soon a I set the alarm the Entry Zone LED is lit even though the one on the relevant PIR is not.

I need to get into the PIR, but in a way that it will go back together again! Anyone recognise it from the image at

[Chris Hogg]

Are you sure it's the PIR itself that's causing the problem, and not the control unit? Can you disable the PIR, remove the battery for example, and see if the fault persists? What happens when you switch off the camera? Incidentally, you said the PIR was wireless in one reply, but that all the wires to the two units were completely separate, in another. Which is it, wired or wireless?

[Mike Tomlinson]

En el artículo , Chris Hogg escribió:

a wireless device still needs a power feed :)

my money's still on a damaged wire to the PIR. The OP's pic shows one wire running up to it under the wallpaper, but there may be another, hidden one running up from it through the ceiling. Opening it up will tell for sure.

[Chris Hogg]

Ah, I didn't know that. Thanks. Which raises the question in my mind as to the point of them being 'wireless', but I guess that's another thread!

[whisky-dave]

riggering signals to the PIR.

How do you know they are not lit ? If they are inside then unless you have bright light in the room they may w ell be lit enough, you might be able to tell from the image you get from th e camera if teh colours of the image look a bit washed out or monochrome co mpared with say what your smartphone sees it could be that the IR LEDs are almost always on a bit. I used to notice then on my webcam as the light sta rted to fail even a clody day could mean the IR LEDS came on.

[F]

It's the camera which is wireless. The PIR is wired.

I have had a different issue with the alarm panel (false panics) but this problem started immediately after I installed the camera.

Switching the camera off has made no difference.

Once I get into the camera non-destructively, I can bypass it and see what happens then.

With that in mind, I might just pick up a spare PIR. Any particular ones recommended?

[F]

Ah, OK. I assumed they were not lit because i couldn't see any glow from them until it went dark. However, turning the camera off has not got rid of the problem...