The best way is to buy an adapter from a marine retailer (Marinco, Hubbel, etc.). The second best way is to make one but you have to be sure of what you're doing and it won't be waterproof.
ABoatman,
Thx, do you have a model number, or what it would be called? Would it plug into the shore end of my cord?
Thx
What's the best way to provide 110v 30a source to a 50a boat, to run the 110v stuff? Like the charger. I occasionally run into a situation where 110v 30a is the only choice, like at home where it's docked.
It would plug into the end of your shorepower cord.
I think this is what you want but you would be better off going to the store to make sure:
https://www.westmarine.com/buy/mari...-to-50a-125-250v-female--12998381?recordNum=2
This seems way more expensive than it needs to be so they may have a cheaper adapter in another brand. You're looking for something with a male 30 amp plug and a female 50 amp receptacle. You would plug your 50 amp cord into one end and plug the other end into the 30 amp shorepower pedestal.
Thx, I've seen these, expensive and poor reviews. There has to be something out there that works.....
Works fine with a galvanic isolator and not sure why it wouldnt.
I haven't really got a clue about that.
It came up relative to questions about how to charge batteries while on the hard. I allowed as how all I had to do was plug in a single 30-to-50 pigtail, connect that to the boat power, done. (Actually, I was even starting with a household 15A circuit out in the yard's back lot; had to use an adapter from that to 30A first.)
Some of the other owners said that didn't work for them because they had galvanic isolators (starting the year after ours was built). Something about needing two legs for any of their chargers to work at all. Unless maybe they happened to have 240V chargers? Ha. I hadn't thought of that.... Bet that might have been it.
Edit: another "Ha!" It was "isolation transformer" that they mentioned, not a galvanic isolator. If that makes any difference...
-Chris
I have a 50 amp service. An adapter, 50 amp female to 30 amp female, plugged into the boat makes it into a 30 amp service. Then a 30 amp shore power cord eliminates the need to muscle around the much heavier 50 amp cord. I have been able to run both a/c units at the same time plugged in to 30 amps.
If you have an isolation transformer on your boat (a heavy and expensive device but nice to have) you don't need a galvanic isolator. That could prohibit using a 30 amp to 50 amp adapter.
I blew it (brain f... ?) ,the adapter is 50 amp female to 30 amp male.
IF a 30 A light weight power hose is used the 240 plug will simply have the red and black wires connected.
This works fine ,,,until you forget the vessel is only getting 30A and you turn on too much load.
The 30A plug will loose a terminal in its black wire., or you could melt the 30A wire.
Yeah, I don't have either, hence my basic lack of understanding how they work, or symptoms when/if something doesn't work...
And we have no 240V appliances either, so the simple 30-to-50A adapter works fine for light loads.
I've asked the other owners for a memory refresher, so maybe the guys who told me about it in the first place can help me clarify whatever the heck it was I was trying to remember...
For a 50 amp boat at a marina it's possible to buy a "Y adapter that allows the boat to have full power by plugging into two shore receptacles (as long as they are on opposite "legs"). And of course if only one is available or they are both on the same leg you still have 30 amps available.
For the home dock, I would look into the cost of rewiring it for 50 amps.
They say unless that transformer has a legit 240V (208+) feed, nothing on the other side of the transformer will work, no matter whether a 220V or a 110V appliance (or charger).
-Chris
I don't actually know what an isolation transformer does... or why...
-Chris
Second, they block "stray currents". By making the boat ground reference not connected to the dock ground reference. In enginneering speak, an iso transformer blocks common mode currents. Including, lightning induced Line to ground surges.
You need a GFI for the vessel, not an isolation transformer that solves the problems of sray current from the dock opr other boats.