One Circuit trips shore power

[ehschneider]

EVERYTING WORKS fine with generator. When I plug into shore power the breaker ON THE DOCK trips. It ONLY trips when I flip the MICROWAVE circuit on inside the boat. Otherwise the dock power is fine... I tried other plugs on the dock as issue.

I am not attempting to use the microwave, just flipping the dedicated switch om the boat panel causes the dock to trip.

I disconnected the shore power, started the generator. No power fluctuations and used the microwave with no issues..

I plug back into the dock..It trips as soon as I flip the microwave circuit on..
Shore power plugs new and clean. no burns

360 Mariner... Thanks all

[BRHEAUME]

Here's two things to try:
Unplug the microwave and turn on the circuit on shore power and see if it still trips.
Also, have you tried another plug at the marina or on a trip somewhere else at a different marina?

[bud37]

welcome to the forum.......follow the above suggestion, sounds like your microwave may have a short that is triggering the gfci at the dock....good luck

[ehschneider]

I haven't unplugged the mico. I hate the plug is buried behind it and the unit is fastened in the wall.... I tried 2 other trees in the marina. TRIPPED...

Then I went to the town docks..Plugged in and NO PROBLEM. MICRO WORKED PERFECTLY.. Just like when I run the generator.

I came back to my slip, plugged in. turned on the microwave circuit in the panel and...... IT Tripped the dock tree..
I just don't understand.
THOUGHTS???

[bud37]

If it is leaking to the neutral/ground then the sensitive breakers at the marina may be picking this up.......town docks not so much.....you will have to unplug it and test the micro for leakage IMO......it is important to follow thru with this, if it is leaking it is a hazard.

Do you have a marine experienced electrician to check it out for you and is this a new issue with your shore power?

Perhaps there will be someone else that has run into this and has a solution for you.

[bud37]

Actually if you unplug the micro as has been suggested, you can test the circuit by just closing the breaker without anything plugged in.......it is possible to have a short in the original wiring also.

[ehschneider]

ok... unplugged and removed the microwave... Flipped the breaker, no dock trip..

Plugged micro into a different outlet that was GFI'ed and POW, it tripped the dock again..

So my awesome micro/coffee maker combo is dead. CRAP>>> what will I put in its place... Now I have to have a coffee maker on the counter. WHAT A PAIN!!!

[Phrancus]

A combination of microwave and coffee maker is new to me.

I doubt that that thing is beyond repair if it works elsewhere.

[Midnightsun]

Some marinas have GFCI shore power which is causing issues with many boaters. Something is obviously different with your marina pedestals as you say it works fine with generator and other marinas. https://www.powerandmotoryacht.com/main ... hore-power

[km1125]

It's quite likely that microwave/coffemaker can be fixed. It has some leakage from 'hot' to the grounding (or case) which could just be a defective surge protector.

They changed the specs over the years on GFCI sensitivity for marine dock outlets. Old dock power systems actually had NONE, so your microwave would work fine on those - as it does on your generator which also likely has NO GFCI. When the code was upgraded to require GFCI on dock systems, those were implemented with "standard" GFCI which were VERY sensitive. These were replaced with a SLIGHTLY less sensitive system which avoided nuisance trips.