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Low shore power voltage

Discussion in 'Technical Discussion' started by NYCAP123, Jul 2, 2013.

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  1. NYCAP123, Jul 2, 2013
    #1
    NYCAP123

    NYCAP123 Senior Member

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    At the two marinas we've been in with the 56 Hat I noticed that we're not getting enough voltage from our shore power. The Marina manager claims they're reading 208V at the pedistal, but we're only drawing 180V a/c. At the other marina it was worse. It was recommended that we add a transformer to our shorepower, but that would involve dragging out 70 lbs every time we dock and leaving a very expensive piece of equipment on the dock.

    Any ideas or suggestions for a way to boost our voltage besides living on our gens?
  2. jhall767, Jul 2, 2013
    #2
    jhall767

    jhall767 Senior Member

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    That kind of voltage drop doesn't just happen. A transformer is not going to fix it. Something else is going on. 208V may be the tip off. Are you verifying voltages with an independent meter? That's a more typical voltage for 3 phase. With no load you should measure the same voltage in the boat as at the pedestal. Where are you located and what type of shore power does the boat require?

    If it's a traditional 120/240 what is the voltage of each leg to ground and between the two legs.
  3. Marmot, Jul 2, 2013
    #3
    Marmot

    Marmot Senior Member

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    Use the same meter to measure the pedestal and your AC buss. Are you reading 180 from a meter on the switchboard? Do you know it is accurate?

    A 30V drop is kind of unusual unless there are wiring issues and even then it would probaly only show up under a load. What do you read before closing the boat's breaker?
  4. Pascal, Jul 2, 2013
    #4
    Pascal

    Pascal Senior Member

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    Doesn't it have an isolation transformer where you can adjust the input voltage with jumpers or moving terminal? Most hatt MY do

    208v isn't ideal but usable. Anything below that will damage equipment. Have you actually measured the voltage at the pedestal with a quality multimeter? I would start there. My nr one tool on board is a multimeter....
  5. NYCAP123, Jul 2, 2013
    #5
    NYCAP123

    NYCAP123 Senior Member

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    I've been unable to put a meter on anything (2 days, 2 docks and I've been unable to go back on board since due to an injury). My readings on the boat are from the panel meters Marmot. I asked the marina we're in now to check the accuracy and got a blank stare.

    The first marina I went to was showing I believe about 150V where I started popping the pedistal breaker. Moved to another dock where I was getting about 170V. At this we didn't pop the breakers, but couldn't run the a/cs.(This was on my stbd side 50 amp S.P. At the marina I'm in now my meter shows 180V on my port side 50 amp S.P. I only have the marina manager's say so about them having 208V).

    Two days on board a month ago isn't nearly enough to learn it. Tell me about this Pascal. It sounds like it might be exactly the answer I'm looking for.
  6. jhall767, Jul 2, 2013
    #6
    jhall767

    jhall767 Senior Member

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    Not sure about your particular marina but it sounds like they have 120V /208V 3 phase. There is no real 240V single phase available. 208V across any two legs but they are not separated by 180 degrees. Single phase 120V works fine.
  7. Marmot, Jul 2, 2013
    #7
    Marmot

    Marmot Senior Member

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    Before you start bumping up the voltage willy nilly it is a good idea to make sure of what you actually have on your distribution buss.

    Throwing volts at what might or might not even be a problem other than an uncalibrated meter might invite some big repair bills.

    Does that boat have a ground detector?
  8. Pascal, Jul 2, 2013
    #8
    Pascal

    Pascal Senior Member

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    My hatt is an early one, 1970, and has no isolation transformers so I am not familiar with the details of how they are set up.

    But before messing with it, I would check voltages with a good meter at the pedestal, then at the end of the shore power cord or at the terminal block if the boat has cable masters. Then at the main panel, directly at the rotary inlet.

    I doubt the marina would have voltage that low. I really suspect a connection issue, either cord or plug. Many hatteras have those barrel fuses near the inlet, they are a major source of headaches and fire.

    Each time Check voltage on each hot to neutral, and across both hots. That's the onl way to be sure.

    I know George (caltexfla) has a 56, hopefully he ll chime in sit the xformer
  9. NYCAP123, Jul 2, 2013
    #9
    NYCAP123

    NYCAP123 Senior Member

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    Agree. Hope to be allowed to walk in about a week. Ibviously from the yard's blank stare DIY troubleshooting will be necessary. Surprisingly no ground detector that I'm aware of, but there are a couple of unlabled lights that could be polarity.

    Anything you can tell me about the isolation transformer. From memory I'm thinking there might be a voltage booster on boad, which I'd have to assume isn't working if it's there, but maybe it was an I.T. Right now I'm gathering education while I sit here frustrated until I can get on board.
  10. Capt J, Jul 2, 2013
    #10
    Capt J

    Capt J Senior Member

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    208v sounds like they broke up 3 phase electricity, without adding stepup transformers on their end. The other issue is in most marina's i've stayed at with this situation, all of the boats of course use more amperage because of the lower voltage causing more issues and even lower voltage because they cheaped out by splitting 3 phase to begin with, and then don't have enough supply, wire size etc to carry the current when every slip is full, it's hot outside and everyone's running a lot of air conditioning. And then there are the melted electrical items.......and sometimes resulting fires......such as a common occurance at one marina down in Miami........

    I do have step up transformers on a boat that is in a marina like this. It steps up the voltage to 220-230 volts. We had to do this because the old SMX I air conditioner controls would not allow the a/c's to run under 208 volts and would just flash "lo ac". It is not 70lbs, more like 25lbs or so. One of them Lean Marine (ft. Laud) sold me......another one I picked up at Sailorman. They weren't terribly expensive......
  11. NYCAP123, Jul 2, 2013
    #11
    NYCAP123

    NYCAP123 Senior Member

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    That's the plan.

    Don't. I know Chelsea had a problem at the first slip, and I suspect at the second, but we do also which that I.T. could certainly fix. If not we may have to add a voltage booster, but who wants to tell their boss to lay out another 2K. Certainly not until I'm sure it's the fix.

    Many hatteras have those barrel fuses near the inlet, they are a major source of headaches and fire.

    Good advice. Electric is my definite weakpoint. Thanks for the tutorial guys. This old Hat is compounding my knowledge every day I'm aboard. Hopefully I'll start spending serious time aboard in a couple of weeks.
  12. chesapeake46, Jul 2, 2013
    #12
    chesapeake46

    chesapeake46 Senior Member

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    Hi,
    Are your neighbors experiencing any issues ?
  13. NYCAP123, Jul 2, 2013
    #13
    NYCAP123

    NYCAP123 Senior Member

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    Yes. The Hat next to us has a voltage booster on the dock, but I DK what they were reading. I've never run into this on the newer boats I've run, and the other Hat is the only one on the dock with the booster.
  14. NYCAP123, Jul 2, 2013
    #14
    NYCAP123

    NYCAP123 Senior Member

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    A Charles booster I just checked on was 50 lbs. and about $1,900. Boosts 18%. The one on the dock for the boat next door was built by Ward. I'm told is 60 lbs and was about $1,500. It also doesn't look very waterproof. If we install one I'd make it an on board permanent installation.
  15. chesapeake46, Jul 2, 2013
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    chesapeake46

    chesapeake46 Senior Member

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    Are these boosters " smart "?
    in other words, do they self adjust or do you need to manually change taps ?

    If it's a maunal adjustment booster you'll need to check voltage at every marina you get a slip in to keep from cooking things if said marina's voltages are higher.

    There are so many reasons you could be experiencing low voltage that it's hard to troubleshoot from a keyboard.

    Any chance the marina might hire an electrician to look at the whole system ?
  16. Capt J, Jul 2, 2013
    #16
    Capt J

    Capt J Senior Member

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    The ones I've dealt with were lighter. I wouldn't make it a permanent installation because you don't use it at all marina's or even most. Kind of like how you always carry a 2-30amp to 1 -50amp splitter, but only use it once in a while. Do you have a splitter on board that you can try? You might do better voltage-wise pulling off of 2-30amps in some marina's. It's worth a try.
  17. NYCAP123, Jul 2, 2013
    #17
    NYCAP123

    NYCAP123 Senior Member

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    Good thought.
  18. NYCAP123, Jul 2, 2013
    #18
    NYCAP123

    NYCAP123 Senior Member

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    Although I'd certainly check, it does appear to be smart. The lit says 'When voltage drops below 220V it increases voltage by 15%'. Would hate to get a 15% boost and have the marina's supply surge for whatever reason without it cutting off.

    Not a chance. We're transient.
    Don't I know it. Maybe it's just my lack of knowledge in this field, but it seems there must be a reason at our panel that we're not getting enough of the voltage available. I doubt the meters are wrong (at least by much), because they read correct when we're on power from the gens.

    Those barrel fuses that Pascal mentioned earlier leaves me wondering. If they're aged could they be blocking the voltage feed?
  19. Pascal, Jul 2, 2013
    #19
    Pascal

    Pascal Senior Member

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    Well they could cause a resistance and reduce the voltage...

    Feel the cover and around the housing for heat.
  20. NYCAP123, Jul 2, 2013
    #20
    NYCAP123

    NYCAP123 Senior Member

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    Hey that'd be a simple fix. I'm a firm believer in the KISS principle. I'd almost make bet we figured it out. It makes sense given the symptoms. If not I've got plan B, C & D all set.

    Other than basic or emergency repairs my electrical knowledge is "Call the guy". I figure there's a reason electricians need a license. But if the KISS principle doesn't work I feel like I just took a course at YF University. Keep the thoughts coming.
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