swapping a magnetic contact

[jc69817]

Hi guys
Im having a problem with a zone on my alarm (Accenta+). The zone contains 4 magnetic contacts and is on a chime circuit. I am getting a lot of false alarms all on this zone. Is it a simple job to change the contacts or even better is there a way I can find out if 1 of them is faulty.

Many thanks guys

 

[sparkymarka]

Remove one contact at a time untill your false alarm stops !

 

[jc69817]

yeah I thought of that pal. But is it a simple job to swap them or do I need to get someone in ?
also is it easy to swap a surface mounted one for a flush one ?

 

[sparkymarka]

Are they wired daisy chain ( from one contact to the next ) or all back to the panel ?

 

[jc69817]

I'm pretty sure they will be daisy chained as 3 were added well after the initial install and linked into the orher

 

[SandyLyon]

Providing the cables are all ok it should be a simple enough job, do you have the engineer code (makes it a little easier but not a deal breaker)

You should be able to remove the part containing the reed switch without the alarm sounding, once you remove the tamper wires (assuming the tamper is connected) the alarm will / should sound, your user code should silence it.

Make a note of the wiring (photo always handy) and replace each magnetic contact wiring as per photo also replace the magnet part on the door / window, press reset and fingers crossed all should be well.

One thing to note if the alarm was professionally installed is that some installers program the panel to require an engineer reset on tamper.

Good luck, if it's got a global tamper there will only be 4 wires, a pair connected together (tamper circuit) and a pair connected across the reed switch (zone alarm circuit)

 

[secureiam]

it is a simple process of elimination, depending on how its wired will make it very easy and quick, or relatively slow to find the problem.

 

[SandyLyon]

it is a simple process of elimination, depending on how its wired will make it very easy and quick, or relatively slow to find the problem.

Agreed, but for what new magnetic contacts cost, while you are unscrewing them to check them, you may as well replace them with new.

 

[jc69817]

Thanks guys. That my job for next weekend sorted.

 

[EightyTwo]

It's just a thought... but why don't you go round and tap each contact with a screwdriver handle (when all the doors are closed) and see if you get a chime? I'll bet that it's a loose screw connection somewhere and this could tell you which one to look at first.

Fitting flush contacts is not as easy as surface ones. You need to drill a 20mm hole in the door frame and the edge of the door. These holes need to line up perfectly, so measure twice (and again) and drill once. If the gap is tight, you will need to chop a shallow rectangular recess for the flange on the contact and magnet - use a 3/4" (19mm) chisel and a mallet. Then you need to drill a hole (or holes) to get the cables into the bottom of the hole in the frame. You will need to have enough spare cable to be able to wire the contact before pushing it all back into the bottom of the hole and fixing with screws. It could take you a solid half hour to do each one if you're fairly competant at woodworking.

 

[jc69817]

The woodworking side isn't a prob. I served my time years ago but don't do much now.
Thanks for the insight though. Are the flush ones easy to wire (if I have enough spare) ??

 

[EightyTwo]

Are the flush ones easy to wire (if I have enough spare) ??

Yes - only slightly more fiddley than the surface ones.

 

[jc69817]

Thanks for your help guys. Bought 4 new contacts. Changed the oldest one (all I had time for) and no false alarms since