The DMC, or Dual Master Controller, is basically a CPU-in-a-box that allows two converters to be controlled simultaneously from the same CPU PCB (604170). Through two pairs of handshaking lines, the converters enter and exit High-Z mode when entering and exiting parallel operation to facilitate load sharing.
The DMC also features AGC, or Automatic Gain Control, to maintain tight regulation of the converter output voltage when the converters are loaded—needed particularly when the converters are in parallel and the High-Z behavior is in use as the output will droop more significantly. AGC (use is optional) requires sense voltage of the common converter output bus before the last circuit breaker and connection to the ship’s bus, and is switchable via a dry contact.
The intended purpose of the DMC is to manage a pair of converters which are permanently connected between the incoming shore cord or generators, and the ship’s bus. Hence, the ship’s bus is always powered by the cleaner output power of the converter(s), and seamless transfer is performed by simply turning one converter on and the other one off.
A DMC configured electrical installation is NOT compatible with other forms of seamless transfer (ASEA or other).