Shore Power Tripping GFCI breaker

[tomschauer]

https://gilwellbear.wordpress.com/2015/ ... t-sensors/


Here are some ideas....

[vineyardgray]

Thanks for the words of encouragement gents!

There is no galvanic isolator on board that I am aware of or can find.

I had to swallow my pride and admit that I was out of ideas and could use some professional assistance. So I had a marine electrician who the club recommended here to have a look and he's just as stumped as I am

The main breaker on the house power side of the panel came apart due to removal and reinstallation of the cables during troubleshooting, so he'll be back tomorrow with a replacement and more head scratching.

[bud37]

I think you chose wisely, I know with mine it took a long time for me to find the short, had to take every circuit on board apart to check continuity to find where in the branch it was and that boat was far less complicated that your is....good luck and I hope he finds it sooner than later.......

Fyi...if you have an isolator it will be right at the AC panel, it is basically just a diode to stop power coming back to your boat thru the safety ground to save underwater metal parts and make anodes last longer. You need to be aware of them because they can throw you off while testing the safety ground side......

[km1125]

Qr Bbpost
Battery charger. Started as an audible short then started increasing in ohms. The longer I hold the meter, the longer It increases in resistance. WTH?

That is very typical measurement when there is a capacitor between the two points you are measuring. They may have it there to filter spikes out of the incoming line, but typically that would be between line and neutral.

I would disconnect and terminate the lines AT the range, microwave and battery charger first, then plug it in and see if the problem goes away. Then hook each one up and test for a while again.

And I definitely agree on testing the isolators. The diodes there have a voltage drop. If there is less than about a volt difference between the shore power ground and the boat ground, they are essentially disconnected, so there won't be little trace currents flowing. However, once that voltage increases over a volt, then they start conducting and it acts as a short between the two. Since the shore neutral is connected to the ground at the panel, you have the ability to trip the GFI by sending current via the ground instead of the neutral.

[Marvin]

Hello. I'm having pretty much the same issues with our Santego, today i disconnected the power wires off the ac brackers coming from the inverter. So far haven't kicked the breaker. Every thing works but the outlets.
Marvin..

[bud37]

Welcome to the forum Marvin....hopefully someone can help.... what is your boat year , size etc to help the guys........

[Cooler]

This may not help but just in case nobody checked to be sure. I had similar issues 2 seasons ago when I pulled into my slip for the 1st time that year. Went to the dock master to inquire about potential dock issues. His response was " no, nothing strange here. Turned on the main power breaker for that pier, it's all good." After a week of scratching my head, I returned to the boat to continue search for a short onboard. Walking down the pier I met an electrician replacing floor panel from deck. He said a wire had broken loose, due to ice push, 3/4 of the way down the pier. It was not suspicious until the boat next to mine reported the same main breaker pop. 220V was pushing into our electrical. So, although everything seemed normal to the dock master, it was the facility equipment, not my boat. ( Of course after I spent hours trying to locate short on my boat ) They should have at least noticed the number of dead fish on the bottom near that break. Normal at one box, circuit problem at another box, seems like the marina equipment.

[vineyardgray]

Sorry for the delay folks, just wanted to close the loop on this one.

Multiple things were causing the main breaker to trip
#1: One of the breakers for the shore power had failed internally. Had to drill a new hole in the panel to replace as they don't make internally linked breakers any longer (the tie bar is external now by code)
#2: The light that shows inverted shore power was improperly wired. I would not have figured that out on my own.
#3: The water heater is 'leaking' power: Suspect the element is fubar. Pulled the ground for the remainder of the season. Will replace element in springtime and retry.
#4: The old ProMariner Charger triped the breaker immediately. Also wiring too small for a 40A charger. Bought a Victron inverter/charger so will be figuring how to make that work in early spring!!

There wasn't much season left by the time I got 'er to Port Credit, but I was at least able to power stuff using shore power for the remainder! I got out for under $1k for the electrician too!