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50 amp 220v boat into a single 30 amp 110 v shore power ?

Discussion in 'Technical Discussion' started by Worthy vessel, Jul 25, 2020.

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  1. Worthy vessel

    Worthy vessel Member

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    Is there any way to plug a 50 amp 220v boat into a single 30 amp 110 v shore power
  2. NYCAP123

    NYCAP123 Senior Member

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    Yes they sell step-down pigtails and adaptors at most marine stores for 50 to 30 and 30 to 15 or 20. Understand though that you won't have all the power you need. Most likely you'll have no a/c, and in the long run it may shorten the life of things like refrigerators. You can also get "Y" connectors to plug your 50 into (2) 30's. Not cheap, but every 50amp boat should have one aboard. Often you'll find a transient slip to fit your boat but it's been set up with (2) 30's and no 50. If you only have one 30 available you can simply plug in one leg of it. So my advice would be to bite the bullet and get that if you can't get both.
    Last edited: Jul 25, 2020
  3. Capt J

    Capt J Senior Member

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    Not really, most everything will not work. However, you can get a Y and plug into 2- 30amps on the dock and that connects to your single 220 volt 50amp and business as usual and everything works.
  4. Worthy vessel

    Worthy vessel Member

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    I have 2 30’s to a 50 y adaptor but where I want to go there is only one 30 available for each slip
  5. Worthy vessel

    Worthy vessel Member

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    Don’t forget I am stepping up voltage
    I think I need some kind of transformer
  6. Worthy vessel

    Worthy vessel Member

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    Could do a 30 to two 30’s and then two 30’ to a fifty but I think it will not work because the 30’s source has to be out of phase.
  7. NYCAP123

    NYCAP123 Senior Member

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  8. Capt J

    Capt J Senior Member

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    You cannot make 220 volts from a single 30 amp. Almost nothing on your boat will operate, and most likely neither will the battery chargers. It depends on what side of the 50 amp they're on and which side you're getting power on. You NEED at a minimum 2- 30 amps and a reverse splitter to a single 50 amp for your vessel. Perhaps you can get a 60' 30 amp cord and go from a pedestal not being used to a reverse splitter as well as the 30 amp at your slip to make 50 amps. Is there even enough depth at this dock? As I've NEVER seen a slip that could accomodate a 62' Motor yacht at a marina, not have at least a single 50amp outlet minimum. If you can't run the battery chargers and at least a single chiller and keep the boat 80F inside where your boat is docked (Florida), you will end up destroying the interior of your vessel among other things and it may even sink if the batteries go dead, which usually takes less than a week for batteries to go dead on a motoryacht of your size, even with everything turned off.
  9. Pascal

    Pascal Senior Member

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    Single 30 amp service at larger slips is indeed very rare in SoFl. I ve seen it up north a few years ago but not down here or in the Bahamas. Once slips hit 35/40 you get at least a single 120-240/50.

    what will work when connected to a single 30 depends on the wiring and what you have. None of the 240v items will work and only some of the 120v circuits will work.
  10. Oscarvan

    Oscarvan Senior Member

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    Assuming the two 30's are counter phase.
  11. NYCAP123

    NYCAP123 Senior Member

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    I've run into it several times though out the mid-Atlantic, NE and in Canada. As I said earlier for traveling the reverse Y will keep life normal. The single pigtail or adaptor is to get by on. You'll probably watch TV, run your laptop, radio or vacuum, and keep your batteries charged. You won't have air conditioning, water heater, stove, clothes drier and I'd be judicious about how much I used my fridge unless it's dc. Think 1950's cottage.
  12. Capt Ralph

    Capt Ralph Senior Member

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    You have to remember the lines coming down most docks are 230Vac, 60Htz in the states. 30A, 115Vac service is either one half of the 230Vac or the other.
    Realistically you can not get 230Vac from a single 30A, 115 vac outlet. But if yo capture the correct 115Vac outlets that make up that 230Vac line down the dock, With the correct Y connect, yes you can.
    Tap on me directly and tell me where your at. I'll offer better info and help make things work.

    Personal remark removed by admin.
    Last edited by a moderator: Jul 25, 2020
  13. cleanslate

    cleanslate Senior Member

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    Have the yard put in another 30 amp plug for you and use your two 30 amp Y 50 amp adapter. See if they will do that . They might with a pre paid slip contract. You never know. Just ask.
  14. chesapeake46

    chesapeake46 Senior Member

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    If you dont ask, the answer is always "No". ;)