GFCI & Cruisair

One condenser unit for the master cabin is 5 yrs old, the other two could be original (salon & forward cabin). The forward cabin is the larger unit.

Zoom in on the 3 small trigger boards on the PR8X pump relay board in post #7 (2 on left side & 1 on right side) with the red & white wires coming off of them. Why is one lead cut on the large resister on all 3 of them? You can see it clearly on the one on the right.

Tonight I disconnected the red, black, and green wires at the pump relay board and the condensing unit (power leads from panel breaker), the white wire is not connected at either board. Same result, with all breakers off, the pedestal trips instantly when I turn the A/C & Pump breaker on at the panel. Yet all the A/Cs work on a non GFCI breaker. Is the next step to disconnect the wires from the panel breaker?

Capt Ralph - The Big Dig was a mess and a pain but I can get to the airport from Randolph (the next town to Braintree) in 15-30 minutes even at rush hour. But try to go anywhere else at rush hour, forget about it.

The last 5 years we had our 28' Cutwater at Hingham Shipyard Marina, but they didn't have a bigger slip for us. They were just building Hingham Shipyard Marina about the same time as the Big Dig. We were spoiled with all that's around Hingham. Bay Pointe Marina in Quincy is now owned by Marine Max and is their Boston hub.

NYCAP123 - I hear your concern and share it. Although I've done a fair amount of wiring, I'm not an electrician, and believe I know when it's above my level and when to stop. I have changed breakers before and am very careful and methodical when doing anything like that. Re-wiring the panel is not something I can or would do myself. Isolating the issue safely by process of elimination I believe is doable. Repairing depending on the results is another thing.

Please explain about the divers.

Thanks again for all the posts.


Last night I did more troubleshooting and re-troubleshooting. On Ocean Yachts they put the 230v pump on the same breaker as the salon A/C. I removed the pump leads from that breaker and put them on an open spare 220v breaker on my panel. I was able to run the (2) cabin units and the pump without tripping the fault breaker. I let them run for about 30 minutes with no issue.


Attached is the label from the salon condensing unit which is the larger of the 3 units. There are 2 inline fuses mounted on the electrical box of that unit. I removed those 2 fuses and was able to turn on the panel breaker without tripping the ground fault. I think it's safe to say the problem is with this unit but I didn't have time to go any further.

Capt Ralph, you mentioned the triac, and I've read these need to be a certain type.

I have one 50 amp shore power cord. My pedestal is the only one on the dock (Bay Pointe Marina, Quincy, MA) with a ground fault breaker. I have been able to troubleshoot with other pedestals, but it is a little harder now that the marina is filling up and the pedestals are all being used.

Good catch Capt Ralph; The A/C units in the engine room were mislabeled. The larger unit in the engine room is for the salon. So originally I was troubleshooting the wrong unit.

1. Both the A/C and the pump is 240v. previously I posted a picture of the back of the original wiring on the 240v breaker for the Salon A/C & A/C Pump. The double red wires above the double black wires are coming off the right side of the breaker. There is a separate box that has the pump relay assembly board with (3) small trigger boards (it hold up to 8 trigger boards, model PR8X). I cut the red and black wires that go to the pump relay board and connected them to an unused 204v breaker.
2. There are 3 wires that go from the pump relay board to the actual pump, black, red, and ground. One of the first things I tried was disconnecting all 3 of those wires at the pump which did not change the result.
3. There are no white wires connected on the panel side or on any of the A/C units or pump relay board. They are there but have all been terminated (capped and tapped at each end).
4. The larger A/C unit for the salon does not run when the (2) fuses are removed. The only change is that I can turn on the panel breaker for that unit without tripping the ground fault. With the fuses in the ground fault trips immediately when turned on.
5. The 2 fuses appear to go to what is labeled as "Emergency Operation Control" which is a 3-position rotary switch labeled "Off - Heat - Cool" and has a large transformer attached to it. Then the leads from there run up to the connection for the pump relay board. You can see the blurry image of the rotary knob in the picture with the 2 fuses.
6. Only 2 of the 3 heat pumps work along with everything else on the boat. The only thing that does not work is the salon A/C unit, which trips the ground fault.
7. One thing I noticed today was that the salon unit has the black wire from the panel connected to "Line 2" and the red connected to "Line 1". The other 2 units and the pump relay board have the opposite configuration.

Since I'm fairly certain I narrowed the issue to the one compressor unit, I plan find an A/C tech to find the issue and repair.