More details. How many wires go to the door? Does "door station" mean there's a speaker at the door? Does intercom audio run over the wires going to the door? At first I thought you were saying that the Nutone runs on DC but rereading, I'm not sure.
What does the Nutone manual/tech service person say about this? What are the model numbers of the door station and the main chassis?
There's an existing working door station and an existing working chime that runs on how many volts AC?
A good answer is easier with a clear question giving the make and model of everything. "The biggest problem in communication is the illusion that it has taken place." -- G. “Bernie” Shaw
