Hello,

I have a DSC Power Series 632 system with a 1555mx main board. The system is monitored and TLM is enabled. I am getting a Trouble Code #3 whenever my phone line goes off hook. The trouble disappears when the phone goes back on hook. The monitor company is getting messages all day long about phone line being restored. I check the incoming voltage for T&R on the panel. I have 50v dc when the phone is on hook and about 6.5v dc when the phone is off hook. The system communicates just fine with the monitoring company. I am only having problems when I am trying to use my shared phone line.

Any ideas????

Jason

 

If I had to guess, I'd say that whoever wired the alarm into the telco in did it backward or wrong. When the phone is off hook, it creates a short on the line and the voltage that the TLM monitors drops.

Either your house phones are wired upstream of the alarm panel, or they simply tapped the alarm into the phones like a normal extension line. You might possibly have a phone that's marginal as well.

 

Well... I connected the wiring on both ends. (The good news/bad news is that if there is a problem with the wiring, its my fault... LOL)

I connected the red/green pair to the analog demarc outside the house and fed that to the Tip/Ring of the panel. Then I backfeed the line back outside on the black/yellow pair. I connected all of my telephone Inside Wiring to that black/yellow pair.

I think the TLM is supposed to throw a trouble code when the voltage drops below 3v dc. I have tested both the telco incoming and the return on the panel when I have a phone off hook and it still shows 6.5v dc.

I guess I could connect my butt set directly to the return which would effectively disconnect all of my inside wiring and I could try going off hook and see if I throw a trouble light.

Jason

 

So far, it all sounds like you got it right. There may be a pecularity on one or more of your house phones. Some of the cheaper phones (and more expensive ones) can produce some odd effects.

 

Ok... Here is what I did this morning to test...

I disconnected the yellow/black pair coming out of the alarm panel and connected my butt-set directly to the panel on the return side. Within a few seconds of going off hook with my butt-set, the alarm goes into trouble and comes out of trouble when I go back on hook. I tested the voltage on both sides of the panel. I'm still getting 50v dc on both sides, but now I only get 5.5v dc when I'm off hook.

Also, after browsing the net I see that most people have a RJ31x jack before the alarm panel. I don't have that. My telco line comes straight into the panel from the demarc.

Any ideas?

Jason

 

Try the same voltage test directly at the Demarc, with nothing connected but the butset. If you get the same voltage drop hooked directly to the telco, then the problem is that somethings flakey with your phone provider's incoming line. If the voltage stays at a decent level, then there might be a problem with the dialer on the alarm board. The RJ-31x is primarily to allow you to remove the alarm system from the phone line by simply unplugging a cord. It's just a 8 pin jack with a simple switch mechanism to take the place of the phone relay inside of the alarm that's normally connected. Having one makes it easier to eliminate the alarm as the source of the trouble, but it's absence would not cause this effect that you are seeing.

Basically, it's either bad incoming line condition, or the alarm has an issue.

 

What are the ramifications of disabling the TLM.

As I understand it the TLM will set the alarm off if the alarm is armed and the phone line is cut/disabled. However, if the alarm is not armed, then the TLM will through a trouble code.

I will test the phone line in the morning, but I'm guessing that the odds are that the TLM is flaky on the board.

Jason

 

If you are not in a situation where you are not worried about anyone monkeying with the phone lines (and most people aren't, the kind of crook that knows enough to disable a phone line isn't generally going to target a typical residence), it's probably not a real issue.

Try disabling the feature. At worst, it may be a symptom of a bigger problem (lightning damage often comes in via phone lines, and can manifest months after the actual surge).