I installed a Comswitch 5500 on a wired Verizon 2 line ksu-less phone system, don't know model number. This has 5 phones on it, if I hook up more than two phones the line lamp lights. The voltage out of the Comswitch on the phone port side is 30 volts, this voltage doesn't drop as I add phones. I tried splitting the phones between the phone out port and the TAD out port no help, tried reversing the line, in and out no help. Presently I've removed the Comswitch. Comswitch tech support has never heard of this problem and says it must be a compatibility problem between that phone type and the Comswitch. I've only put this on SLT's and KSU's and never had a problem, but I've never tried putting them on a ksu-less system before. Has anyone else ever had or heard of this problem?

Retired phone dude