The rotary dialer is coded "41". it requires 18 Volts AC to operate the synchronous motor that drives the dialing mechanism.
You should apply 18 VAC to the violet/orange pair of the telephone mounting cord at a convenient point in your wiring scheme (connecting block, 66 block, etc.) You can derive the 18 volts from a separate transformer, or from the 18 V tap on the key system power unit. Unlike the 18 V that is used for the 3- and 4-type speakerphones, which can't be grounded, the power for the dialer **CAN** be grounded.
I think the DTMF version is coded "40" which **would** be polarity-dependent. The DTMF dialer does not require the external power supply, since it dials out in real time as the dialing card passes over the contact matrix, on its way up.
Take a look in this handbook, and scroll down to page 34:
bsp https://www.ridethemindway.com/phon...201980%20%20470%20PAGES%20%20325-094.pdf
