Alarm door analog value debug

[pete_c]

This morning I noticed one of my alarm sensors (door) values fluctuating between 149 (it has an EOL resistor) and 155.

The wires are fine at the alarm panel. I redid the door frame a couple of years ago and put a new switch at the time with an new EOL.

Curious what would cause the sensor to fluctuate from 149 to 153? It triggered alarm very early this morning.

Just noticed that the value went to 161. Taking it out and replacing it today.

What would cause this though?

 

[BraveSirRobbin]

First thoughts are loose connections or connections/conductors that are shorting to each other. I would take a multimeter and without the leads connected to the M1 measure resistance and see if it is fluctuating. Make sure your fingers are not touching the bare wire/meter leads.

Bang on the sensor with an object while doing this as well.

 

[pete_c]

Thank-you BSR

Checked wiring to be fine. Pulled sensor from door frame. Think its a sentrol sensor. I have a box of these so replacing it. I noticed different analog values using the sentrol magnet and a rare earth magnet. Sentrol magnet gives me an alarm analog value of 150-152. A small rare earth magnet gives me a value of 148 which is what all my other door sensors are at. Wierd though cuz I have never seen this issue with the other sensors in the house for the doors. I will check it with a multimeter and not connected to the panel. It appears though to have gone defective on me. Never seen that before though.

 

[pete_c]

Just twisting the ends of the wire together I still see the analog value still fluctuating from 148-152.

So now replacing the EOL resistor; which really doesn't make sense to me. Never replaced one before. Everything is soldered in place.

 

[pete_c]

I found my issue. I had replaced part of the door frame last year.

That said I did replace the contact switch cutting and soldering the leads from old one to the new one.

I never really checked the leads from the 22/2 alarm wire to the contact switch wires that were soldered about 10 years ago.

Today I fished the wire back down to the basement rafters (extends a bit beyond the foundation some 4 feet).

I found my shrink tubing / soldering had pulled apart some from the rewiring last year. I cut the end of the 22/2 and fished it back up to the door frame. Twisted the end wires and my analog values now remain at 148 with no hovering up to 152.

This little wiring debacle tripped the alarm at 3 AM this morning.