No AC power to panel! Helped a friend solve a goofy power issue today on his C-248 C.

johnnydanger

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Joined
May 21, 2026
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Non-Fluid Motion Model
Sargo 25
Vessel Name
Spindrift IV
Today I had the pleasure of hunting down an AC panel power issue on a friends boat. Thought I'd share the details as I'm sure some of you may experience something similar someday.

I'm sure most of you are blissfully unaware that the C-248 inverter (and I assume most Cutwater inverters) is hidden in the wall behind the table area. Additionally, you're probably blissfully unaware that ALL OF THE AC POWER ON YOUR BOAT IS FED THROUGH THAT SINGLE INVERTER. So when you plug in that shore power cable, guess what? The outlets, microwave, etc. are all receiving that power THROUGH the inverter (internally auto switches to bypass mode when shore power is plugged in). The reason is that then the inverter can auto-switch between shore power and battery power based on what's available. But it also is a major fail point that most people are unaware of, and it's inaccessible unless you have long arms and some know-how.

To top it off, for some reason Cutwater decided to hide the inverter somewhere inaccessible and not use a GFCI remote breaker that is accessible on the front of the panel. This means that there's a GFCI outlet hidden in the wall in a nest of wires, and that it's almost out of arms reach.

Here's the breakdown. Hope someone finds it useful.

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THE ISSUE
Inverter was lit up, shore power master switch was on, shore power was plugged in, master breaker and battery charger lights were on, but none of the AC breakers would light up so outlets/microwave/etc. were dead.

THE CAUSE
The Inverter that’s hidden up in the wall behind the master battery switches has a double AC outlet that the AC panel is plugged into, and where all the AC power comes from. That outlet has GFCI and somehow was tripped—thereby causing the AC panel to not receive any power. This is confirmed by not seeing the green light on the Inverter outlet, as shown below. All AC power is either passed through the Inverter (from shore) or the inverter is converting it from the 12V house batteries.

THE FIX
Reset the GFCI. To do so you need to reach waaaayyyy up into the wall through the nest of wires and poke at the RESET button on the outlet.

Diagram.png
 
Thanks for the post, this would be one of those maddening problems to sort out. Knowing the approximate location of the breakers etc is very helpful. I have a c-24 and assume its setup is the same.
 
Apparently setting up a system where there's an AC sub panel downstream from a GFCI plug on an inverter is not a great thing to do. The reason is that each outlet on the boat should have a GFCI for safety, but putting two layers of GFCI such as the setup here makes a system prone to nuisance GFCI tripping.

It sounds like many inverters have GFCI on the inverter outlet to meet a government regulation for safety, but these types of inverters aren't really intended for an application where the inverter feeds a sub panel that then feeds a bunch of GFCI outlets. This is only an issue on US inverters, in Europe there is no such concern. In any case, it would have been nice if Cutwater added a panel to allow access to the inverter, mounted the inverter in a visible location, or better yet used an inverter that had a remote GFCI breaker or that had no GFCI and instead opted for the alternative. Sounds like an inverter can have a large label stating "THIS DEVICE IS DOES NOT HAVE GFCI, MUST INCLUDE GFCI ON DOWNSTREAM OUTPUTS".

No matter, the solve is simple if your inverter GFCI outlet trips, you just need to know about it!
 
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