Last summer we ran into issues with plugging our 1988 3818 into shore power. In each case the marina had “upgraded” the ground fault system to the new ABYC regulations which lowered the allowable ground fault from 100ma for x duration to 30ma for less than x duration. It took a while to work out with an excellent Marine Electrician, largely because of my schedule and wanting to do the necessary modifications myself, then there were the two surgeries that slowed things down.
I made a ground fault tester using one that intended for contractors and blows at 2ma and 30 amp connectors. The knee jerk reaction from lots of people was that it had to do with the inverter and the time it takes for it to process that there is 120v power inputting. In the “unplugged” condition the unit is in a grounded condition, when power is input, the ground is opened. However, that takes a few milliseconds.
The way my inverter was installed by a previous owner, the load (hot, black wire) bus was cut to form a sub panel of breakers. This sub panel has a “master” switch to activate breakers for the fwd & aft outlets, microwave and refrigerator. There was an “input” load wire going to the inverter, neutral connected to the neutral bus, ground to the ground bus. On the “output” side, the load wire goes to the “inverter master”, the neutral goes to the neutral bus and the ground to the ground bus. To make sure I had the correct neutral matched with the load I started by disconnecting all of the neutral wires and removed the factory bus. Then, starting with each load wire at the breaker, followed it back to the sheath, took the neutral and followed it to the connector and labeled it. Repeat, repeat, repeatedly.
The issue with ground fault was solved by breaking the neutral bus into three. One bus for line one on the breaker panel, a second for line two on the breaker panel then a third bus for the inverter circuits. I can now plug my test gfi into either line or the splitter and not have an issue.
There are going to be a bunch of us with this problem as marinas change to the new regulation. Hopefully you can use my solution as a guide and save you a bunch of frustration.
I made a ground fault tester using one that intended for contractors and blows at 2ma and 30 amp connectors. The knee jerk reaction from lots of people was that it had to do with the inverter and the time it takes for it to process that there is 120v power inputting. In the “unplugged” condition the unit is in a grounded condition, when power is input, the ground is opened. However, that takes a few milliseconds.
The way my inverter was installed by a previous owner, the load (hot, black wire) bus was cut to form a sub panel of breakers. This sub panel has a “master” switch to activate breakers for the fwd & aft outlets, microwave and refrigerator. There was an “input” load wire going to the inverter, neutral connected to the neutral bus, ground to the ground bus. On the “output” side, the load wire goes to the “inverter master”, the neutral goes to the neutral bus and the ground to the ground bus. To make sure I had the correct neutral matched with the load I started by disconnecting all of the neutral wires and removed the factory bus. Then, starting with each load wire at the breaker, followed it back to the sheath, took the neutral and followed it to the connector and labeled it. Repeat, repeat, repeatedly.
The issue with ground fault was solved by breaking the neutral bus into three. One bus for line one on the breaker panel, a second for line two on the breaker panel then a third bus for the inverter circuits. I can now plug my test gfi into either line or the splitter and not have an issue.
There are going to be a bunch of us with this problem as marinas change to the new regulation. Hopefully you can use my solution as a guide and save you a bunch of frustration.
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