electrical Issue

Hello I have a 1987 mainship Nantucket. I am have a issue with shore power . I have 2 inputs “LOAD I” and “LOAD II” . I also have a switch 1 , 1&2 and Gen above breakers . When in position 1 the all breakers in the panel work. When I switch to postion 1&2 I loose all breakers on right side of panel . Looking for suggestions on what issue may be . Thanks for the support

You need to make this easier to understand what you have.

I am guessing you have a 50a 125/250 power cord that gives you a Line 1 and a Line 2.

Maybe you have two 30a inlets one on either side of the boat and this gives you a choice between the two switches.

Usually there is a shore or Gen switch. The 1, 1&2, Gen. does not sound normal but could be doing any number of things.

If your skill level is not electrical, may I suggest you call a marine electrician.

Good luck

tiltrider1 said:

You need to make this easier to understand what you have.

I am guessing you have a 50a 125/250 power cord that gives you a Line 1 and a Line 2.

Maybe you have two 30a inlets one on either side of the boat and this gives you a choice between the two switches.

Usually there is a shore or Gen switch. The 1, 1&2, Gen. does not sound normal but could be doing any number of things.

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I have attach a photo to help clarify problem

Alaskan Sea-Duction said:

If your skill level is not electrical, may I suggest you call a marine electrician.

Good luck

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Absolutely.

It looks like you need to flip the top breaker on the right side (load 2) to "on", have you tried that yet? If the "reversed polarity" light goes on when you are flipping it switch it off immediately.



When the selector switch on top is set to "Line 1", line 1 powers both the left and right sides. When it is on "Line 1&2" line 2 will power the breakers on the right side which you can see are the ones that can draw a bit of current. When on "Line 1&2" the voltmeter on the right should also show voltage. If it does not then there is an issue with the feed going to the selector switch and if it does show voltage but breakers are still dead there there's a head scratcher there and you should probably get an electrician to poke at it. But for right now make sure that top main breaker on the right bank is switched on when you are testing it.


Good luck and hopefully it's something simple!

Thanks I have tried that , no luck . The only way I can get power to all breakers is to put switch in position 1 and and turn on breaker 1 . Is this configuration breaker 2 is not in use .effectively all sub breakers are working off main breaker 1

Confirm you have a wire hooked to the line 2 on the back of the switch.

Do you have a single 125/250 volt 50 amp shore power cord or two 30 amp cords?
Did it used to work correctly and now does not or is this an old problem?
What happens when you run the generator?
Do you have an inverter?

Yes this is a new problem . Working for years. I went to boat and both main breakers 1,2 were off. Not sure why but when I proceeded to flip them on only breaker 1 would function . Breaker 2 would go on and (would not trip )just no power to sub breakers on right side of panel. All this occurred with rotary switch in 1&2 position. The only way to get power to both all breakers is to position the rotary switch to position 1 which the eliminates main breaker #2

I do have a inverter which seems to be working

The generator is not installed

Thanks

Thanks Michael. When I position the rotary switch in the 1&2 position the voltmeter on right side shows no voltage does this indicate to you the issue is with the switch or the main breaker#2 ?

That would be an issue with the switch, so it would let you know you're getting power to the breaker. As mentioned earlier, do you have one shore power plug or two? If you only have one that explains it, and there will probably not even be a cable connected to the back of the switch. If there happens to be one connected you can follow it and probably find an extra shore power plug tucked away hiding somewhere. Is it easy to access the back side of the power panel?

Since we have no idea how your boat is set up we can’t offer any solutions. I never got an answer about your shore power set up. Is it a single 30a 125v, dual 30a 125v, 50a 125v, or 50a 125/250v?

The other question not answered was what happens when it is switched to generator?

At this point I doubt it is a switch issue but that can not be ruled out at this point.

It’s possible that you burned a wire completely off the switch or a fried circuit breaker. A little diagnostic work with a multimeter would tell us we’re the electrons stop at and that would tell us the culprit.

Thanks everyone for your input . I have dual inputs to the boat the are on the same side of the boat which have breakers . I used a single cable 50 amp service connected to a “Y” cable which connects to load 1 and load 2 input receptacle. Which the connects to main Breaker #1 and #2 . I did a visual inspection and appears No burnt wires or loose connections . This was working a few days ago so I am confident that the wiring from shore power to boat is correct and working. I think the issue is with the rotary switch or breaker . Let’s hope the breaker since the which is discontinued . Just not how to confirm which one

Have you swapped shore power cords between cord inlets? Have you ruled out the power pedestal?

Time to break out or purchase a multimeter and follow the electrons. I would start by checking for voltage at both sides of the breaker. If you have no voltage on either side of the circuit breaker then check both sides of the switch. If no voltage on either side of the switch then check the end of your shore power cord. It won’t take long to find we’re the electrons stop at.

Yes I have tried swapping the power cord . I even went directly from power pole directly to both inputs individually . Eliminating the “Y” cable The problem appears to stay with input #2 . I will break out the multimeter and see what I come up with thanks

If you are not comfortable with a VOM, I would get somebody who is and play assistant by flipping power on and off to the boat as he/she checks different locations for the missing voltage starting with the end of your power cord.

You posted a picture of two push style circuit breakers. Oddly the line 1 looks popped. First I would push it to see if it resets and solves the problem. If not I would unscrew the plate and take a voltage reading on both sides of each breaker.

Thanks , that is a older photo I was using it as reference . The push breakers seem to working fine, but I will check the voltage to be sure.

Are those breakers inside or outside?

Inside the boat apparently there is breaker box for all outlets somewhere. The panel outlet switch does not light up when turned on.

Those breakers are on the outside

I don’t think those breakers are rated for exterior use. One of them may have gone bad internally.

Unless you enjoy the chase more than using the boat, call in a marine electrician.

My '08 MS 34HT is set up similarly with 2 - 30A inputs and a transfer sw that allows everything to run off #1. Only difference is I don't have the rotary selector.

From what you describe my guess would be that main breaker #2 has stopped working / won't connect but that's only an educated guess. Breakers get old and do experience failures. I would start checking w a VOM where you 125V and where you don't when Sw is set to 1&2 and both breakers are on. Above easy enough if save w a VOM and you get access to the back of the panel.

My reasoning is the set up worked before w 2 inputs and from what you described something caused both #1 & #2 breakers to trip. What ever that something was might have been enough to cause one to fail open and no longer function. It's a place to start. If V in but not out that confirms breaker is the issue.
If no V in or out of breaker then you need to back track points along line #2 to see where you have & lose V...
Rotary sel sw, breaker at boat inlet, boat inlet, cord #2, pedestal.
I think you said you swapped cords #1 & #2 so those should be OK and issue is between inlet and breaker #2

Kmart said:

Thanks I have tried that , no luck . The only way I can get power to all breakers is to put switch in position 1 and and turn on breaker 1 . Is this configuration breaker 2 is not in use .effectively all sub breakers are working off main breaker 1

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You are using 2 cords Correct?

Cartouche said:

You are using 2 cords Correct?

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He is using a Y at the boat and has swapped ends with no change. This means the problem is on the boat.