

First thing to do is check the phone lines to see if either one uses a 9 to get a outside line. When I went back after their repair, the telco line voltage was 48.5 vdc and all has been well since. (Digital telco line by Cox Cable) The cable company found the trouble on their side, but I wasn't there when their tech was, so I don't know what they found. I had dial tone at the panel, and all seemed ok, but when I measured the telco voltage it was 22.5 vdc. The cell unit kept reporting telco trouble.

I had a similar problem on a residential burg installation with a Telguard TG-7 cell backup unit.
