Why does my home alarm keep tripping?

scarletjim

Last night, our home alarm went off several times whilst not 'set' – roughly 7.30pm, 9.30pm, 10.40pm - and each time, it went off repeatedly, i.e. we put the code in, but it tripped again immediately, about 6 or 7 times on each occasion before being ok again for a while. Every time it was the ‘tamper’ light that was flashing, which I’d not seen before…

Good old internet suggested that the back-up battery can cause such issues if reaching the end of its life, but we have checked the battery and it is fine (we did this with the Skype help from my girlfriend’s electrician father) so it's not that.

Does anyone know what else it could be? I’m happy to call the experts, but as usual would like to check anything easy and obvious myself first… A couple of possibilities:

1. I read that if the tamper loop ‘goes open circuit’, then this would be a very likely cause, however how would this cause it to trip repeatedly on three separate occasions yesterday evening, but not again since then? Why would it be so inconsistent?
2. When we opened the control panel to check the battery, we saw that one of the components looks rather burned – could that be the cause? (Please see pics - link below, please let me know if it doesn't work)

Thanks to anyone who can assist. 

https://www.dropbox.com/sh/am1gcqcsj062vkn/AADTFryTfi2Mxen1yTDRD5Xya?dl=0

Ant555

Have you recently decorated or put up christmas decorations close to any PIR sensors?

Many of them have a micro switch that triggers when the case is opened and mine started a period of instability after I knocked it with a ladder when decorating.

The other time I was getting tamper problems was a wire that was run by previous owners under some carpet and we think it had eventually worn and one of the cores was connecting/disconnecting. My friend who is an alarm installer replaced/rerouted that wire at the time and it fixed the problem.

When we were having big problems, it was easier for me to kill the alarm but not press reset and just leave the 'tamper' light on. Alarm could not be set but at least it didnt go off again.

Hope this helps

Ant555

There appears to be only one LED on the main box so is your alarm one of these?



If so then does the control panel show tamper for any particular zone - or if a log is available then does that yield any clues?

popeye2755

Is it an Optima control panel?

That resistor looks like it's toast. I can't remember if it's in the charging circuit for the battery. If it is, your battery is probably dead and drawing too much current.

How did you test the battery?

scarletjim

Very helpful posts, thank you.

Christmas decs was a great idea, but sadly we've just got a tree and mantelpiece for our decs (no kids in our household! lol), and they're not near the PIR so it can't be that.

Great advice about leaving the tamper light on if it happens again at a bad time, i.e. at night. I wonder if that's why it hasn't tripped in the last 10 hours - we left the tamper light flashing, I didn't realise that would stop it tripping again as it didn't stop it last night, every time we pressed our 4-digit code it immediately just re-tripped, without us pressing reset...

I should have said this earlier - it's an Accenta G3, so not quite the one you've pictured above. My small panel has 4 LEDs at the bottom: TA (tamper), PA (I assume Personal Attack), DAY and POWER. I'm not sure what they normally do, but right now DAY is green, POWER is red, PA is off, and TA is off (but was flashing before I reset the system a couple of hours ago, and was actually fully red for a few minutes last night after one of the trips). Not sure if any of that helps at all.

The mystery for me is how it can repeatedly trip so much in just a few hours, then not trip at all for many hours. Is it possible that me dusting all the PIRs late last night could have solved the problem? I guess I'll have to see what it does today...

scarletjim

popeye2755 wrote: »

How did you test the battery?

My girlfriend did it, with Skype help from her dad, who is an electrician. She had a device with a selection dial, a digital reading screen, and red and black wires with connecting pins. On his instruction, she put the pins into some 'screws' on on the far right hand side of the big control box, and confirmed that the battery was fine. They then (apparently) also checked in a similar way that the charger was working. (Excuse my obvious ignorance of the detail! Sorry I can't provide more accurate information about what they did).

scarletjim

One quick question - do any of you know if I can ask my supplier / fitter to replace the small control panel (the one with the buttons) with something superior, ideally with a screen to tell me a bit more about any errors that occur? Or would I need to replace the entire system to do that?

spadoosh

Im going to go with a spectacular guess.

Voltage dips in your area (the times youve listed will be around peak demand) meant battery back up kicked in. The battery circuit isnt working right because of the burnt out resistor which is triggering a tamper.

Has the battery ever been replaced? Because theres stickers in that box that suggest its from 2002, if its the original battery its far surpassed its life expectancy.

scarletjim

I had a service 3 years ago, and my notes on the costs suggest that the battery was replaced then. I understand they don't have a particularly long life anyway, but I'd hope a battery would last longer than 3 years...

The house wasn't even built until 2007, so I was surprised to see that sticker in the box...

So far today, nothing - but will be interesting to see if peak time trips it again tonight... If so then I'll definitely get the original fitting company to come and take a look asap.

[Deleted User]

I think you need to find out what that resistor is, and why it's burned. My guess is that it's in series with the input to that regulator, and it's been cooked by a short circuit on the output.

If the fault is inside the box, you're looking for components/wires that are touching or too close, outside you're looking for something that has damaged/shorted the wiring.

Intermittent faults can be a PITA to find, there are some things you can do to flush them out, but at the end of the day if they go away whilst you're looking for them your options are limited to waiting for them to come back or replacing parts speculatively.

Le_Kirk

Unless you took the wires off the battery when you tested it, it may be that all you've done is test that the charging circuit is giving out the right voltage. I came across an Accenta a little while ago that had constant but irregular tamper warnings. I linked out the tamper switches in all the PIR's except one, which I connected via a small switch so that if the fault occurred the owner could switch out the tamper switch. The idea was that if the fault didn't occur for a few days, I would move my little set up to the next PIR. As it happened, I got it second try. Having sourced a replacement PIR, owner decided to replace them all anyway.