One Circuit trips shore power

[bud37]

Source of the post 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

Good article Hans, it illustrates what I have been suggesting for years that residential appliances be checked before install on boats. It is not the marinas that are creating a problem for boaters, it is the poor wiring practices on some boats over the years and some marinas were balancing cost vs marina residency IMO. I am sure that the regulating agencies have electrical engineers that know exactly what the problem is and how to try to correct it.

Electricity tries to return to it’s source at all times, when on generator power it returns to the generator because that is where the ground and bonding returns. On shore power leakage could be returning to the pole thru the water and that pole / ground point could be quite a distance away, that could be is the reason for the shore regs to have been changed, too many electrocution drownings in marinas from poorly wired appliances and boats.

Like it says marinas post No Swimming in Marina for a reason, that also applies to what happens to the many people that fall off their boats or docks and are killed every year due to this issue...

These same appliances at home work fine many times, houses are wired differently in regards to neutral and ground, doesn’t make those same appliances safe on your boat. They may be but need to be checked.
In this case the OP knew enough something was wrong and went about finding out why and correcting it....

In closing , boat ownership comes with serious responsibility so follow the regs, get your boat checked, don't assume anything ( prove it ) and don’t take short cuts with electricity especially now when most of our appliances come from offshore.

Be safe folks....

[AndiamoSeattle]

Interesting that the microwave was the culprit, I will have to check mine!
My 2005 4137 CMY is tripping on the newer docks utilizing the 30 millli amp breakers. It works fine on the generator and my older marinas pedestal. I've had several marine electricians on board to chase down this current leak to no avail ( lots of places this current leak could be coming from). The latest recommendation from the marine electrician is to install isolation transformers which would isolate the current leak. She said chasing down these current leaks is probably more expensive that installing the isolation transformers. Most new boats being built today are including isolation transformers to ward off these issues. The problem with my Carver is that to be ABYC compliant I would have to install 2 isolation transformers for the mid-ship shore power inlet and 2 for the aft shore power inlets. Was quoted 14K for all, YIKES!

[g36]

14k wow that's terrible. Please let us know what you end up doing

[Midnightsun]

Just curious as to why my boat has only 1 isolation transformer capable of 50a at 250v. This is equivalent to 100a at 120v so lots of power is available. No mods by me, all this is factory.

[km1125]

Source of the post Just curious as to why my boat has only 1 isolation transformer capable of 50a at 250v. This is equivalent to 100a at 120v so lots of power is available. No mods by me, all this is factory.

It gives you a full 30A on each side of the 120VAC secondaries (with some extra). Pretty common on larger vessels to be set up like that.

[km1125]

Source of the post Interesting that the microwave was the culprit, I will have to check mine!
My 2005 4137 CMY is tripping on the newer docks utilizing the 30 millli amp breakers. It works fine on the generator and my older marinas pedestal. I've had several marine electricians on board to chase down this current leak to no avail ( lots of places this current leak could be coming from). The latest recommendation from the marine electrician is to install isolation transformers which would isolate the current leak. She said chasing down these current leaks is probably more expensive that installing the isolation transformers. Most new boats being built today are including isolation transformers to ward off these issues. The problem with my Carver is that to be ABYC compliant I would have to install 2 isolation transformers for the mid-ship shore power inlet and 2 for the aft shore power inlets. Was quoted 14K for all, YIKES!

It would be interesting to see the electrical schematic for that vessel to see why they came to that determination. I can't imagine needing four isolation transformers.

[AndiamoSeattle]

I'm told that via ABYC regs. The isolation transformer must be within ten feet of the shore power inlet. The distance between the forward inlets and those located in the transom is over 20 feet. I may buck the ABYC reg and only install the transformers on the mid ship inlets and disconnect the seldom used aft power inlets.I will ask if a single transformer could be used as Hans boat is equipped. That may save a couple of boat bucks?