Hi,

I've just started getting a false alarm on my Texecom Shock/Contact sensor which is on my Entry Door.

It's only happened twice in two weeks, obviously once is too many times. The system has been perfect since install 6 months ago.

Oddly, both false alarms have been at 7.15am and 5.30am, so it got me wondering whether the panel is suffering from mains interference.

Now I've checked for induced AC and it is too high at 1.7vac - 1.9vac, so that is my first port of call.

I've also checked the loop resistance and it's 10.06k (EOL) so that's fine.

Before I get a filter installed, which I need anyway by the looks, I wanted to check voltages on here because they seem a little high.

I can't find any rating for the mains transformer, it doesn't say on it the expected output, but I am reading 18.8v at the panel input terminal (everything connected as normal). I expected to see a bit less. Furthermore, the spec sheet states the keypads operate between 10v-13.7 and I get a reading of 13.7vdc-13.8vdc. Seems like it's on the high side of the threshold...

Now I haven't allowed for lack of accuracy with my meter, however, according to fluke it's 1% or less.

Does anyone know what voltages I should be seeing at the transformer output?

Thanks

Danny

Edited November 3, 201213 yr by Avotronics

I think you may be over complicating it at the moment, id look for more simple things first like at the sensor etc

Is the door solid in its frame?

Has it been more windy than usual?

Have you checked the thresholds for detection.

This is what James means,

I think you may be over complicating it at the moment, id look for more simple things first like at the sensor etc

Hi,

I've checked all the wiring, so it means I have to buy another £15 sensor and it might not be faulty.

But yes, you're most likely right.

Is the door solid in its frame?

Has it been more windy than usual?

Have you checked the thresholds for detection.

This is what James means,

Extremely solid in it's frame.

Wind hasn't been very bad on the days of false alarm.

As far as checking thresholds, I had to bray my fist on the door to get the sensor to react, so there's no way it's over sensitive... unless it's faulty.

Again, I would recalibrate the detector before throwing it.

Again, I would recalibrate the detector before throwing it.

I'll try it now .

Re-do all the connections, check for stray strands,

Door vibrating when closing had been known to back off a terminal screw oveer time if it was not as tighth as thought.

Re-do all the connections, check for stray strands,

Door vibrating when closing had been known to back off a terminal screw oveer time if it was not as tighth as thought.

Thanks.

Done all that now, there didn't appear to be anything wrong.

But it is a well used door so perhaps something had come lose.

I'll reactive that zone and see how it goes, but if it goes off on the morning again I'm going the AC filter route.

for your help.

Put it on soak test for 7 days,

That way it will not go off, but will tell you when you disarm if it has.

TBH, the induced AC isnt that bad. Seen far worse.

Edited November 3, 201213 yr by Oxo

Unfortunately I don't know the Texecom sensor you have, but in general with this type of detector the vibration being looked for is high frequency, not a thump with your fist.

High frequency caused by splintering of wood, breaking glass, hammering of a brick wall etc, not a dull thump.