[Knot On Call]

The Charles AC master control unit that automatically switches from shore power to generator power on my 2004 52 Sovran Salon has stopped functioning.  All incoming power to this unit is operational., however there is no output except for the 30 A service. I lost generator and 50 amp service to the boat. Charles Industries is out of the marine business and no longer makes this unit. Parts are no longer available., and I cannot find a replacement on-line. Has anyone removed their malfunctioning control unit and replaced it with a simple manual switch to control power to the boat? Please feel free to contact me on my cell at 610-883-3921. Thank you.

[jclark003]

A rotary switch can be used to replace the MC. I haven’t done it myself but have talked to someone who did. It’s not really that complicated unless you want to keep the ability to have both 30A and 50A shore services simultaneously feed the panel. Otherwise it’s just switching three legs from either of the isolation transformers or generator to the two bus outputs (paralleled). You can also abandon the 30a service and use an automatic A/B switch (just like what switches your bow and stern shore power connections) with the generator on the A side, the 50a isolation transformer on the B side and the output feeding the paralleled bus outputs to the panel.

Before heading down that path have you tried the manual override switch? I had a similar problem to what you are describing and that got me to where I could automatically switch the 50a sources (generator and shore).

[Knot On Call]

A rotary switch can be used to replace the MC. I haven’t done it myself but have talked to someone who did. It’s not really that complicated unless you want to keep the ability to have both 30A and 50A shore services simultaneously feed the panel. Otherwise it’s just switching three legs from either of the isolation transformers or generator to the two bus outputs (paralleled). You can also abandon the 30a service and use an automatic A/B switch (just like what switches your bow and stern shore power connections) with the generator on the A side, the 50a isolation transformer on the B side and the output feeding the paralleled bus outputs to the panel.

Before heading down that path have you tried the manual override switch? I had a similar problem to what you are describing and that got me to where I could automatically switch the 50a sources (generator and shore).

thanks. What about the 30 A input if trying the manual override?

[jclark003]

I really don’t know and the documentation doesn’t cover it very well. The switch has three positions (I think center is for normal operation). I connected a 50a cord, disconnect the 30a and threw the switch. I can’t remember which direction but the service came alive and it would switch to main gen as well (and parallel the outputs). 30 A would not work (at least for me) with the override set.

Do your panel lights work and if so will the 50a light come on when the cord is plugged in?

[Knot On Call]

I really don’t know and the documentation doesn’t cover it very well. The switch has three positions (I think center is for normal operation). I connected a 50a cord, disconnect the 30a and threw the switch. I can’t remember which direction but the service came alive and it would switch to main gen as well (and parallel the outputs). 30 A would not work (at least for me) with the override set.

Do your panel lights work and if so will the 50a light come on when the cord is plugged in?

No light on the interior panel or master controller itself. I do have 50A power to the controller confirmed on the input connection.

[jclark003]

Have you checked the isolation transformer to see if it is operational and passing power to the MC? You should hear the internal contactors throw 10 seconds after you plug in the 50a service. Pretty noticeable thunk.

If the isolation transformer is working then the light not illuminating isn’t a positive sign as it could indicate that the internal PC board has failed. The board senses power from the different sources and then energizes a series of contactors to send power out two buses that feed your AC panel. The contactors can still be purchased but if the PC board failed there is none to be found. I would still try the override switch

[Knot On Call]

Jclark003 As I do have 50 A service confirmed to the input bus bar on the MC , the general consensus was a blown circuit board early on which is why I was going to remove the unit and replace with a manual switch. I will try the override switch. I am currently connected to 30 A service to the boat. I did not want to disrupt that doing your test. Is there a sequence I should use to shut off the 30 A then try the 50 A or generator? Is it possible to discuss this and some other electrician issue on the phone? My cell is: 610-883-3921 in the Mid -Atlantic area. Thanks.