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Shore Power

Discussion in 'General Yachting Discussion' started by Kats Call, May 22, 2022.

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  1. Kats Call

    Kats Call New Member

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    Looking for some help. My issue is that when I go to switch my power panel from generator to shore power my main breaker for the shore power pops instantly. The polarity is correct and verified by the panel and the generator running or not doesn't effect this issue. Everything works perfectly with the generator running (lights, tv, AC, fridge, ect). I have 120 at all legs coming into the boat at the dock. I have 120 at each leg as it hits the EATON WMZS2C00 main breaker which I have replaced. I also have continuity through the breaker when on. I can reset the breaker and it holds but as soon as I go to the main board and engage the switch to shore power it blows that breaker. I have turned off every breaker I can find and it still trips the breaker? its a 99 Viking Princess 52 fly Bridge. Thanks in advance for any ideas or help.
  2. Pascal

    Pascal Senior Member

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    More details needed

    Where is that main breaker that trips and which you replaced? Is it next to where your shore power comes in the boat or is it on the main panel.

    on the main panel, how do you switch between shore and generator? Do you have a rotary selector switch or do you have a couple of breakers with a safety slide so only one can be turned on?

    Can you post a picture of the panel?

    Ao far it seems to me that the problem is between the Eaton main breaker and the transfer switch. Could be one of the wires between the breaker and the switch that chaffed or maybe even got hot and melted insulation. Or it could be the selector switch itself especially if you a previous owner has been switching it under load.
  3. Kats Call

    Kats Call New Member

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    The one that trips is under the dash. It is next to the mains coming in, but not tied to them.

    I have posted a picture of how I switch from shore or a back to generator. Its just a simple toggle on the board. There is no other switch that I’m aware of.

    The switch on the main panel and the Eaton is probable not the “main” that comes in. I’m not an electrician by any means, so mislabeling this or the function is more likely the case. I been trying to find a transfer switch but have had no luck.


    The breaker that is tripping is more like an interrupter maybe? Very small wire’s in and out but doesn’t allow for shore power. I can only up load one at a time it appears. I will post second pic... thanks again for your time and help.

    Attached Files:

  4. Kats Call

    Kats Call New Member

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    Had to resize it.

    Attached Files:

  5. mapism

    mapism Senior Member

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    Eaton isn't one of the brands I'm more familiar with for these components, but if it isn't a thermal-magnetic breaker, it definitely looks like one.
    What is really weird is that "C0,5" indicates (again, with a small benefit of the doubt for Eaton components) that the breaker is supposed to trip as soon as the current flow is above 0.5 Amps.
    Which is close to nothing, and surely nowhere near enough to work as the main breaker on a boat like yours.
    Mine is of similar size and has a 63 Amps main breaker, if you see what I mean!
  6. Kats Call

    Kats Call New Member

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    I think I know what your saying, as soon as it spikes above 5amp it's tripping. I'm not sure why it would be doing that now. The boat is parked at my house and nothing changed from the time I brought it home in March of last year, till last November when I went to put it away is when I noticed it wasn't working. I guess I need to see if the load and line coming from the house is causing a spike in AMPS? Which now I'm just making things up LOL.
  7. Capt Ralph

    Capt Ralph Senior Member

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    Is this a new to you boat? New dock? What work has been done? When did it all last work?
    Boat brand, model and year?

    Those lil switches are for the meters, I don't think transfer switches or breakers.
    If you do not have a manual transfer switch, you may have an auto or remote transfer box somewhere.
    Auto transfer boxes are notorious for problems.
  8. mapism

    mapism Senior Member

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    Not FIVE, but 0.5!
    I mean, half of an Amp, which is a sort of practical joke.
    I can't even think what line/usage it could be meant to protect...
  9. Kats Call

    Kats Call New Member

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    I got the boat last March 2021. It is parked at my house. I had the shore power wired when I got the boat to my house. The shore power worked up until some time around November of last year. when I went to put it away for the winter it, I noticed it wasn't working. the last day I used it was November 8th . About a week or two after that is when I went to winterize it and noticed it wasn't working. I did put two new sleeves and pistons in the port motor before this issue started, but weeks before. I have a 40' motorhome that has had auto transfer switch and have had issues with it in the past. I relate that to this as its similar. I've been trying to find information on a transfer switch but can seem to find much. I feel like there has to be a transfer switch somewhere but where?

    The boat is a 1999 52" Viking Princess Flybridge.
    Thank you!
  10. mapism

    mapism Senior Member

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    Don't take this as anything more than an educated guess, but based on what you said so far I'd hazard the following:
    The shore power switch (which judging by the pic of your electrical panel can't be man enough to handle directly the whole current load of shore connection) is likely meant to power a remote relay somewhere, probably not far from the shore power socket.
    If so, that switch could power the breaker that is tripping, and downstream of that breaker you could have the line powering this relay.
    So, the breaker could trip just because this relay is absorbing 0,5A or more.

    Now, it's puzzling that it used to work, and out of the blue it didn't anymore.
    But the ridiculously low rating of the breaker could have something to see with that.
    I mean, let's say that the shore power relay used to absorb 0.4A while on, and the breaker didn't trip.
    But over time, due to a bit of wear/oxidation/whatever, the relay slowly began pulling a bit more current while turned on.
    In fact, it takes close to nothing to increase the absorption from 0.4A to 0.5A, hence making the breaker trip.

    The easiest way to check this theory would be using a clamp meter and measuring the current flow.
    But if you don't have it or don't know how to use it, you could as well replace the breaker with one rated for 1A, and see what happens.
    Mind, in principle it's always a bad idea to replace a tripping breaker with one of higher rating, so I would agree with anyone arguing that I'm giving you a somewhat dangerous suggestion... o_O
    But I'm saying this because it's totally unrealistic that the wires downstream of the breaker are so thin to overheat and possibly melt just due to a difference of 0.2 Amps or whatever.

    PS: don't ask me to refund you the boat if you would set it on fire by trying something you read on the internet, of course! :D
    Kats Call likes this.
  11. Capt Ralph

    Capt Ralph Senior Member

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    EATON WMZS2C00
    I'm thinking this breaker is a fault/hold down breaker to a relay somewhere.
    A dual pole; one pole to hold down the relay, the other to open on over current.
    Poor mans GFI possibly.

    What new appliances have been installed? Charger, micro wave, anything?
    Past this, it may be safer to call in a real marine tech.
  12. Pascal

    Pascal Senior Member

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    Not very familiar with the European systems.

    not sure what you mean by “The one that trips is under the dash. It is next to the mains coming in, but not tied to them”

    That Eaton breaker has to be the breaker feeding shore power to the panel

    Judging by the these two small rocker switch, there has to be some circuitry and relay which actually transfers power to and from gen and shore. There mus also be circuitry to prevent both source from being activated at the same time. The fault has to be in there.

    i notice the LED next to the shore power switch is missing. Could the wires be loose behind the panel and shorting things out?
  13. Capt Ralph

    Capt Ralph Senior Member

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    The Eaton breaker mentioned is not the main feed breaker. Rated at 0.5A.
    Please re-read post #11
    Remote auto transfer switches and load relays can get complicated some times.

    I remember nightmares on Carvers with similar equipment.
    Open relays in a gas boat. It was a long time before my bad dreams stopped. I'll be pissed if they come back now.
  14. Kats Call

    Kats Call New Member

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    I like your style, dad always says you cant be scared. LOL
  15. Kats Call

    Kats Call New Member

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    We haven't added anything. To me its like a transfer switch. Generator runs everything with no issues. I cant get the shore power to even turn on. I have shut off every breaker I can find. I just don't know where to find a transfer switch?
  16. Kats Call

    Kats Call New Member

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    I pushed out the LED by mistake. I need to put it back. If you look at the Eaton Breaker in the Pic you will see the Mains coming in. I'm not sure what the things are to the side of that breaker? Anyone got an idea?

    Attached Files:

  17. LM Viking

    LM Viking Member

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    I know it is a long shot but have you tried to contact Viking service for advice/ or location of a transfer switch if present? And really out there is it possible to get a schematic of electrical for the boat.
    I know that’s wish’n hope’n :)
    chesapeake46 likes this.
  18. Kats Call

    Kats Call New Member

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    I have not, but I probable should.
  19. Pascal

    Pascal Senior Member

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    Ok so since the breaker is only 0.5amp it seems that it is only meant to protect the contactor which is what actually transfers power. It looks like that there is one breaker and contractor for the generator and one for shore power. If the shore power contactor is bad, it would trip that 0.5 amp breaker.

    reason why it’s working fine on generator is that the contactor is working fine and not tripping its breaker (located on the right)
  20. LM Viking

    LM Viking Member

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