Dock power and interior lights- questions.

GBeck

.
Jul 15, 2025
7
Catalina 30 Lake Lanier
New to me Catalina 30.
I had to move my boat to a new marina. When I plug in the AC cord and turn on the battery charger is trips the ground fault on the power tower on the dock.
1979 year model has a Newmar battery charger. Probably came on the boat.
New regulations I found out on ground fault detectors, they are much more sensitive.
Do you think removing this charger would solve the ground fault disconnect.
There is a switch mounted next to the switch panel that was used to turn on the battery charger.
I think if I just disconnect the charger at the charger then this switch won't do anything. See below.

I have added a solar charger I just put on the deck when I'm not there.
It's wired directly to the batteries. They are in series. It charges both batteries.

I also don't have any interior lights. I checked and changed the fuse.

I really don't understand how the AC/DC system works.
When the boat is connected to AC should the AC outlets work. There are only 2.
I don't see any switch to change the boat from AC to DC.

Sorry for the stupid questions. This is the biggest boat I've owned. All my others were racing boats with tillers.
Thanks, Gary
 
Mar 6, 2008
1,367
Catalina 1999 C36 MKII #1787 Coyote Point Marina, CA.
After the shore power circuit breaker trips, if you reset it, does it remain on or does it trip again?
In my case, when I return from a sail and plug in the shore power, it trips the dock CB , but after resetting it it does not trip. This is I believe due to discharged batteries and the charger is trying to charge the batteries and it needs large amount of current so initially it trips the shore power CB.
 
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May 17, 2004
5,732
Beneteau Oceanis 37 Havre de Grace
There should be a breaker or fuse for the charger. If you disconnect the charger that way does the GFCI still trip? If it does then disconnecting the charger any other way will make no difference. You may also need to check other breakers or fuses to take other items out of the circuit to see which ones fix the GFCI issue. If you have a water heater that would be a good place to look too - they’re a relatively common source of the drain that can trip a GFCI.

I’d recommend getting a copy of Nigel Calder’s Boatowner’s Mechanical and Electrical Manual. It’s a really good source for guidance and a good way to learn more about the systems you’re getting yourself into.
 
Feb 26, 2004
23,081
Catalina 34 224 Maple Bay, BC, Canada
I’d recommend getting a copy of Nigel Calder’s Boatowner’s Mechanical and Electrical Manual. It’s a really good source for guidance and a good way to learn more about the systems you’re getting yourself into.
While this is an excellent book, recommend Charlie Wing's Boat Electrical Systems books for beginners like the OP.
 
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GBeck

.
Jul 15, 2025
7
Catalina 30 Lake Lanier
Thanks,
I didn't see a fuse for the battery charger. It may be under a panel where the wires connect. I will check soon.
The GFI trips as soon as I turn on the battery charger even though the batteries are at 13 volts.

Yes, there is a water heater but I doubt it's ever been used. Boat is on a lake and showers and heads near by. But I will remove that fuse just in case.
The depth and speed work so there is DC power at the switch panel.
Thanks for the book suggestions but have restored many classic cars and pretty good with wiring.
Just don't have a wiring diagram for this boat.
Back after the weekend when I can get back to the boat and try the suggestions.
Thanks
 
Feb 26, 2004
23,081
Catalina 34 224 Maple Bay, BC, Canada
Just don't have a wiring diagram for this boat.
They built over 6,000 Catalina 30s. The manuals ARE out there.


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