This unit was specifically designed for Prop Pitch Rotators where long cable runs cause too much loss for desired operation using a RT-21pp. It can be installed at the base of the tower reducing the long run of high current requirement cable, OR with it's higher capacity, it will overcome more of the IR loss of existing cable.
This unit requires an RT-21r for the controller, and 4 or 5 conductor of small guage cable to reach between the RT-21r and the RPU. A standard RT-21 also has the capability of interfacing with an RPU but the RT-21pp does not.
The RPU requires AC mains and is meant to be installed outdoors with it's NEMA enclosure. For indoor mounting, or mounting in a larger equipment shelter, the enclosure may be deleted.