[jclark003]

I had to work on the MC in my 52 and am quite familiar with it. Basically it is a bunch of contactors controlled by a custom circuit board. It has 2 output busses that go to your panel. When only 50 amps are present (shore or main gen) it parallels the service out to both busses. When the 30a is also present it splits the load so that the 30a service powers the B bus on the main panel and the 50a powers the A bus which supplies all the 220V appliances. Generator is treated as a separate 50A input source.

Unfortunately the PC boards can’t be found. The contactors are all available from Honeywell. Based on what you are describing I would guess you have an issue with the PC board. Only way to know for sure is to open the thing up and start metering the contactor triggers to see if they are receiving the signals from the pc board and are functioning properly. I did this on a bench with a friend helping out. Word of extreme caution, everything in there is high voltage and dangerous. And the only way to test is with it hot. Send me a PM if you intend to dig into the thing and I’ll send you the internal schematics.

Does your controller still parallel the 50A service and will it switch over the the generator when running? In other words does everything work when the 50A service alone or generator alone are connected? If so I would recommend you disconnect the 30a supply (inside the controller) for safety reasons and abandon it. 50a should provide enough power for all but really heavy loads.

You can also try the override switch behind the cover on the lower right corner of the box. There is I believe a three position switch. Remember which position the switch is in before trying the override (I think it is center for normal operation). Try the up position first.

If none of that works you are running out of luck. I talked to one owner who’s controller failed and he installed a rotary switch to manually select either the 50a or generator (both output busses tied together). Similarly you could install another A/B switch to automatically switch between generator and 50a shore power, again with both output busses tied together. I’ve seen the 50A Charles switches available on ebay and there are other manufacturers who make marine transfer switches as well. I guess you could pull the PC board and have someone try to repair it (if indeed that is the problem). They would have to do it without the board schematic. I tried to get one from Charles with no luck.

Lengthy reply I know. send me a PM if you have questions and I’ll pass along my phone number.

Best of luck.