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A/C Panel No Power

Posted: June 18th, 2021, 4:32 pm
by Owensned
2005 366MY. Yesterday both power cables plugged into 50 amp splitter on shore power. A/C stopped running. Would run on generator just not shore power. No power showing on electrical panel for A;C. Checked all breakers including under steps.
Switched cords on pigtail connection and A/C panel still not receiving any power while the other panel for all other electrical continued to work.
Thoughts?

Re: A/C Panel No Power

Posted: June 18th, 2021, 4:44 pm
by Midnightsun
You're going to need a volt meter. Check to make sure there is power coming out of the pedestal. If power then check end of power cord for power. Keep on going down the line until you find the problem. It does happen that the breaker inside the pedastal trips so it could be as easy as that.

Re: A/C Panel No Power

Posted: June 18th, 2021, 4:49 pm
by Midnightsun
After rereading your post it sounds like faulty wiring in the splitter. Regardless, break out the volt meter, only way to properly diagnose. Good luck. :captain2:

Re: A/C Panel No Power

Posted: June 18th, 2021, 4:52 pm
by km1125
could be the transfer relays that select between the generator and the shore power. (the "automatic transfer switch") Not sure where they are on a 366, but on a 356 there were in a box behind the electrical panel

Re: A/C Panel No Power

Posted: June 18th, 2021, 5:41 pm
by buster53
Don’t forget, you have breakers on your boat right where your shore power cables connect to the boat, probably within inches of the connections. I had to learn about those the hard way when my AC wouldn’t run

Re: A/C Panel No Power

Posted: June 19th, 2021, 10:32 pm
by tomschauer
If this happened after running genny, you most likely have the one auto transfer relay contacts burnt to the genny side.
This actually happened to me last week.
Behind the breakers are your relays.
With shore power disconnected and genny off open the panel.
The relay on the right should be air con.
You should be able to push on the relay and watch the contacts move.
If one or two don't move they have weleded together.
A small screwdriver should separate them.
Then get in between all contacts with some sand paper.
Should be good then.
Only switch from shire to genny or vs versa with low loads.
No air or water heater on.

Re: A/C Panel No Power

Posted: June 20th, 2021, 6:53 am
by bud37
Just to add, check with a multimeter to verify power off before any work.....especially if you have an inverter wired on board that you are not sure of how it is connected to the boat 120V power.

Re: A/C Panel No Power

Posted: June 20th, 2021, 9:36 am
by km1125
If you do find them stuck and clean them up per Tom's post, you might also check to see if you can find a part number on it. Or take some good pics so you can match it up with a replacement. Cleaning them will definitely work, but won't last as long as a replacement, as there is a plating on the contacts that can get burned or worn off. There are a couple threads on there where folks have identified replacement contactors and sources to get them, and IIRC they were only around $30 or so.