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Old 10-20-2019, 05:18 AM   #3
OldDan1943's Avatar
City: Aventura FL
Country: USA
Vessel Name: Kinja
Vessel Model: American Tug 34 #116
Join Date: Oct 2017
Posts: 4,508
Originally Posted by isphh View Post
I have just completed a survey of a Nordhavn 40 that has an electric issue. The boat’s electric system is powered by two 30 amp circuits, one circuit for the three AC units and the other for the house. The first problem is that the 30 amp circuits each have a 50 amp breaker that needs to be immediately changed to a 30 amp breaker. The boat has three AC units and 30 amps can’t run them all. Is this how the boat is configured by Nordhavn? Should I add a third 30 amp circuit? I’m not sure how to solve this problem. The Chesapeake is hot in the summer so all three AC units are needed.
I moved from a N46 (2X50amp leg) boat to a AT34 (2X30amp leg) boat. I have two A/C and can run them off of one 30amp leg and the house on the other 30amp leg. I will admit, the 30amp house leg can be a challenge. You learn pre-planning and load shedding. SIGH

My best advice is to contact Nordhavn for guidance, for a start.
Realize the Nordhavn, according to Nordhavn, is a 'semi-custom' boat. Nordhavn may or may not maintain records how your particular boat was configured when it left the factory. Then you have no idea how or what the various owners, before you, modified the boat and/or its electrical system. I would still start with Nordhavn.

Consider having 'soft starts' installed on the A/Cs. I have no experience with the 'soft starts' but, I have seen them recommended in similar cases on other boats.

Can you run all 3 A/Cs on the generator?

I agree with you on the 50amp breakers on a 30amp boat. Doesn't seem like a good idea, in my feeble mind.

I hope the above helps.
Did Noah have a get home-engine?
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