POTS lines use AC voltage to make a ringer ring. If it was DC voltage doing it, your phone would always be ringing with talk battery applied. Low loop current symptoms would be poor/low audio on the line.

Chances are, the total ringer equivalence of your three phones exceeds the REN for the line. Each phone should have a sticker on it somewhere with the REN (Ringer Equivalence Number) for that phone listed. Add the numbers up to get a total applied REN. Most circuits have a max REN of 5. If your three phones REN exceeds that, or whatever the actual circuit REN is, you'll have the problem you're having.

Last edited by JBean3329; 03/27/19 07:16 PM.
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