Looking to power a Panasonic KX-T7030 locally for a customer since a DSL tech "used" one of the phone extension pairs to feed the DSL modem. There is no local transformer jack on the phone itself. If I just inject the required voltage on the correct pair at the phone, will that work, or is there also some phone system data on the same pair? It has been a few years since I've dealt with a Panasonic system, and probably would have been unsure then

No. The voice is on the inner pair, the data on the outer pins. You can run a single line set on the voice pair.

Carl

If the KSU is a KX-TD816 or KX-TD1232 model, you can enable the XDP port for that extension number and use only one pair for the phone but you also have to swap the phone out with one that is XDP capable like a KX-T7230.

Thanks for the replies. Kind of what I figured.