What model of 5 pin module should I use in a Circa building entrance terminal that is going to connect digital telephones to the PBX? (Nortel phones to a BCM, to be specific). The cable is PE89 in conduit, about 500 feet or less.

5 Pin Modules
And probably this one? Solid state modules

Thanks.
Jim

I would expect the 75 volt #4B3S-75. I think I would try a 3B3S-30 first though because it offers a lower clamping voltage- 30 volt. But I have no idea what the voltage is on the station pair of that system. If 48 go with the 75V ones.

-Hal

Thanks Hal.