Shore Power

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Joined
Oct 15, 2016
Messages
679
Location
USA
Vessel Name
Speedy Charlotte
Vessel Make
Beneteau Swift Trawler 44
Has anyone connected to an older 50 amp 125v outlet using an adapter? If so, any idea what works and what doesn't? I'd imagine the big question mark is the hvac.

I just bought two adapters, but haven't used them yet. Although I'm moving slips and the new slip had the older 50 amp 125v service.

Thanks,
Mike
 
Has anyone connected to an older 50 amp 125v outlet using an adapter? If so, any idea what works and what doesn't? I'd imagine the big question mark is the hvac.

I just bought two adapters, but haven't used them yet. Although I'm moving slips and the new slip had the older 50 amp 125v service.

Yes I have. The real question is adapt to what? What is on your boat?
 
Has anyone connected to an older 50 amp 125v outlet using an adapter? If so, any idea what works and what doesn't? I'd imagine the big question mark is the hvac.

I just bought two adapters, but haven't used them yet. Although I'm moving slips and the new slip had the older 50 amp 125v service.

Thanks,
Mike

I do the reverse now
 
Hi there, I have 50amp 125/250v on my boat. I have two panels inside the boat. One controls the hvac, the other seems to control everything else.

I was hoping one of the ST44 owners would know since they likely have the same setup, but I'll take any guidance you have to offer!
 
This is typically how a 50A 240/120v shorepower system with two panels inside the boat works:

The shorepower has 4 wires: two hot, one neutral and one ground. From hot to hot you get 240V and from one hot to neutral you get 120V. The boat probably does not use 240V directly. So the four wires go to the main panel on the boat and one hot goes to one panel and the other hot to the other panel, the neutral goes to both panels and the ground goes to the ground buss.

So you now have 120V supplied to each panel but from different "legs" ie hots, from the shore power. That will power up to 50A on each panel.

OK, with that background how do you use a single 120V 50A shore power outlet? I suppose there are adapters that do that but am not sure. The adapter may even let you power both panels by combining the hots on the main panels, not sure. Even if so then you can only use a combined 50A on both panels.

The better way is to use two 50A (or even 30A) shore power outlets that are on separate legs; ie the hots on the two produce 240V across them. There are adapters that take the two 120V outlets and make one 50A 240/120V output. That when hooked up to your boat will power both panels and will have the full 50A per side capability.

Yours is a somewhat unique situation and you may need to consult with an electrican that knows the marina's power system to figure out the best way.

David
 
My boat is 50a 125/250v. I have two adapters for 50a 125v, one wired to power the house and one wired to power the HVAC/WD. If I need the HVAC I just run the house off the inverter.
 
The very first thing that the original poster needs too figure out is whether or not he has any 240 volt air conditioners or stoves on board. They are not going to work on 50/120 at all.
Then he needs to tell us what inlets he has on the vessel to receive power


Only then can a proper adapter set be recommended.
 
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I have the same boat; its like how djmarchand described. I don't think there are any 240 appliances on-board. I actually just purchased a Marinco reverse Y to do 2x 30 amp dock-side to 1x 50 amp 125/250 boat-side and a 30 amp to 50 amp 125/250 pigtail. I got these to have just in case I dock somewhere that only has 30amp which many smaller town marinas that normally do not have larger boats have. I did not look into 50 amp 125 to 50 amp 125/250 because I've been to dozens of marinas between TX and NY and none were using the old 50 amp 125. I would see if the marina is willing to switch the outlet to 50 125/250 if its just changing out the outlet it might be quick and easy. If there are 2x 30 amp available you need to make sure they are on different legs in order for the reverse Y adapter to work. I am guessing that using a 50 amp 125 to 50 amp 125/250 will work but only allow you half the amps as you'd be splitting between two panels. FWIW, someone told me they were able to run most everything off a single 30 amp to 50 amp 125/250 pigtail but I haven't tried it myself. I am guessing if you have the extra HVAC unit and want to use the hot water heater, you will hit a snag but you can manage your loads and probably survive. If you email Marinco they are pretty good explaining things.. if you do post up their response!
 
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Someone related question... if I am adding a Galvanic Isolator, should I get the ProSafe 60 amp or two of the 30 amp model? I have 50 amp 125/250 inlet on my boat that splits off to two panels of 110AC (one for my air conditioners and one for the rest of the AC electrical i.e. outlets, water heater, etc) as mentioned above. Thank you
 
The two legs on your shorepower use a common ground which is what the isolator hooks up to. So use a single 60a isolator on the ground.

David
 
The two legs on your shorepower use a common ground which is what the isolator hooks up to. So use a single 60a isolator on the ground.

David

Thanks ended up finding it in the manual! Is it recommended to connect my bonding? Only some items are bonded others are not. For example, my rudders are bonded to the hull zinc anode but my trim tabs are not and have their own zinc anode. Some thru-hulls may be bonded and others not.
 
Someone related question... if I am adding a Galvanic Isolator, should I get the ProSafe 60 amp or two of the 30 amp model? I have 50 amp 125/250 inlet on my boat that splits off to two panels of 110AC (one for my air conditioners and one for the rest of the AC electrical i.e. outlets, water heater, etc) as mentioned above. Thank you

I had a marine electrician install mine and he recommended the 60.
 
Thanks ended up finding it in the manual! Is it recommended to connect my bonding? Only some items are bonded others are not. For example, my rudders are bonded to the hull zinc anode but my trim tabs are not and have their own zinc anode. Some thru-hulls may be bonded and others not.

Yes connect the green shore power ground to the engine block and the bonding system. Otherwise you could get an AC fault to the bilge, and the bilge and its connected metal would be hot and very dangerous but the AC breaker would not break and the GFCIs in the galley or head would't trip.

David
 
I just got the reverse-Y and 30 to 50 pigtail adapters in-hand. Going to give them a try this weekend and see what kind of load they can handle. The reverse Y was brand new and the pigtail was used once or twice, all for $100 total! New these were almost $600. Definitely check eBay and craigslist
 
I tried the adapters and was able to run most systems off of the 30 amp to 50 amp pigtail. Very impressed. I did not try the electric grill or running any additional appliances plugged in the kitchen (toaster/microwave) so don't know if that would be the tipping point. I guess a potential option for those that do not have 50 amp available.
 
I tried the adapters and was able to run most systems off of the 30 amp to 50 amp pigtail. Very impressed. I did not try the electric grill or running any additional appliances plugged in the kitchen (toaster/microwave) so don't know if that would be the tipping point. I guess a potential option for those that do not have 50 amp available.

Great to hear
 
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