Motion sensor loop issue

[dlmorgan999]

I have a motion sensor that's been giving trouble alerts for quite a while.  I finally found some time to try to fix it.  The loop value is currently reading in the high 150s to low 160s when secure.
 
This is a 14 year old installation, and all the other motion sensors and contacts are fine.  Any advice on what kinds of things should I look at / try in order to diagnose this?
 

 

[pete_c]

1 -Disconnect the switch wires on the PIR and short the NC/NO wires at the PIR end.  Are the Loop values normal?
2 - remove the zone wires at the panel end and short them there.  Are the loop values normal then?
 
If the values remain the same you might have a short in the wires going to the PIR.  The PIR can also have an issue.
 
Here updated my very old PIRs to newer combo PIR Microwave sensors.  I did not have issues with the old PIRs (for over 15 years).
 
You can disconnect both sides and check the wires with a VOM for any shorts if you want.  
 
My loop values all read 147-8 when secure (PIRs and door contact sensors) and 253-255 when open. Have always soldered in place all of the EOL resistors.  That is me and it was a PITA.  I used a mini tiny torch to do this rather than a soldering iron.

 

[dlmorgan999]

Excellent.  Thanks very much for the response (and super fast too!) Pete.    I'll try those things as soon as I get time, and report back.
 
My other motion sensors are also in the 147-8 range when secure.  For what it's worth, I was watching the loop value as I was writing my original post, and I saw the value change from high 150s to low 160s over a very short period of time (10-20 seconds).  That's an interesting behavior that feels more like an issue with the PIR, but the testing should tell the story.
 

 

[pete_c]

Good news !!!  I have had one door sensor wire stretch due to the house settling and had to fix that many many years ago.  It was a PITA to fix.

 

[dlmorgan999]

I was wondering (but hoping not) if I might be experiencing the same thing with stretching.  The other issue I've run into just recently is that the double-sided tape holding some of the contact magnets in place gave out.
 
But issues like this aside, I'm still super happy with the OP2 (I've been using HAI stuff since 1985 in my first house where I installed a 1503).  It's really sad that Leviton stopped making them.  If the board ever fails, I have no idea what I would replace it with.

 

[pete_c]

Buy a hot spare.  The panels are built like the old bakelite telephones. 

 

[dlmorgan999]

I've debated doing just that, but they are definitely getting harder to find.  And I love the phone comment (I'm of the right "vintage" to appreciate it ;-)). I'm still running a board with a ROM (no flash) so that's another reason it would be nice to upgrade.

 

[dlmorgan999]

We'll see if it stays fixed, but it appears the problem was the EOL resistor.  It's not really EOL - I just have it in series at the panel end.  I had screwed down the contacts on both ends a month or so ago, but I just looked at the resistor and it looked fine - I didn't twist it tighter (I should have known better!).  Thanks again for the help.
 
I have one more issue to resolve, but I'll create a separate post about that.