Electrical Question - Breaker kicking off at dock - Please Help!!!

T

tkennedy

New Member
Mar 16, 2005
5
Morristown, TN
Boat Info
1987 Sea Ray 390 Express Cruiser
Engines
454 Crusaders
I have a 1987 Sea Ray 390.

Recently the marina switched out their AC breakers to a GFCI at the dock service panel.

I run (2) 30 amp shore power cords from the dock electrical pedestal behind my boat (dock service panel connects to pedestal behind boat which has (2) 30 amp breakers, then I plug shore power into pedestal which has (2) connections).

When I now turn on shore power at the boat’s service panel (inside cabin) it kicks the breaker off at the dock service panel (not at the pedestal). It doesn’t happen on any other boats at the marina. I even switched the shore power cords to a neighbor’s boat behind me with same result.

I had the dock master temporarily replace the old breaker in the dock service panel. When he did that NO breakers kicked off, BUT, I did discover a burned area on the ground bus bar behind the boat service panel (see photo).

I don’t know when this short may have occurred but it wasn’t there a couple of years ago (might have been when dock switched breakers).

KNOWN:

Shore power cords are in good shape!

Nothing plugged in on boat to AC outlets!

GFCI outlets (2) on boat checked and are not "thrown"


My questions:

1. What would cause the dock service panel to kick off – What should I check on the boat?

2. Could I remove the burned bus bar, clean it up and reinstall it and try again?

3. Are there any circuits I should check on the boat’s service panel with my multimeter? If so, how/what should I check?

4. Any other suggestions?

Thanks in advance!

Tom…
 

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I have a 2002 460 on 220 volts in Spain. It is a European new boat, I have had it 5 years and always, when plugging in to the shore power, it tripped the Marina breakers. Happens every marina I go to and becomes a real pain in the butt, I have to go through a prolonged sequence of events to get the power on.

The worse factor, Spain suffers a lot of power outages, so when the power comes back on after a storm, my boat trips the pedestal and we have no power until I go to the boat again, over winter this can be several months with no battery charger working, not good.

I solved the problem by fitting a Mastervolt Slow Start, I can now plug directly into the shore power with everything already switched on at the DB board, never a problem.

See it here: http://www.mastervolt.com/products/soft-start-transfer-systems/soft-start-13-kva/

Hope this helps.

Graham
 
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You need a new neutral bus bar. That one is definitely cooked. You also need to cut off the ends to the burnt white neutral wires and crimp new ends on them. A mechanical crimper is the best way to go to ensure a good solid mechanical connection. Loose connections cause heat. While you are at it, checked all of the termination points in your AC/DC breaker panel for loose connections.
 
Believe a GFCI breaker or outlet will monitor the current draw on both lines of a circuit.
Power Line coming in(black) is drawing 10A, as an example.
Current passes through your connected load( 12 X 100w light bulbs)
Neutral Line leaving(white) should also draw 10A.
When a difference in the two is present, the imbalance is finding a path to ground(green).
Depending on the rating of the trip module, the difference could be less than 0.10A required to open the breaker.

Your problem is aboard. Definitely repair or replace the burned bus & check for other possible loose connections.

Another method to use, once the bus is repaired, is to turn everything off aboard including the main.
Plug in shore power to the boat.
Start with the main & turn it on. If it holds continue.
Next try each load one at a time, on then off.
You might be able to isolate an issue, time consuming, but it works.
 
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you sure thats a neutral buss? and not just a bonding buss?
Since when is a neutral buss just screwed to a piece of plywood exposed?
 
as BT doctor was saying, is that for sure the neutral bus, its then grounded on both ends. do you have pics of the line side.
 
Hi, It looks to me that the screw that mounts the 2 bars together came loose so it made heat.
I assume the common (return) is the heavy wire on the right.
Current returning on left side heated the junction.
These 2 sides should be joined by a wire jumper.
http://sabercathost.com/13Q2/Wire_Netral.jpg

As for the shore side GFIC trip's, I just ran into this problem myself this weekend.

I am very frustrated because I never have had any problems.

I know in my case I can get the main breaker on, but no circuit breakers. As soon as any breaker is flipped on the dock GFI trips. I looked at my panel and didn't see anything so I am going to start by checking for a bonded neutral somewhere.
Maybe the water heater.

Good luck
 
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