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Electrical Load Distribution

There are 2 - 50 amp distribution panels. Please help me understand why and what the difference is between them.

And, if I want my inverter to power only my refrigerator on AC (Dometic gas/AC) can I turn off the all the breakers except the one labeled refer?  We have an upcoming 18 hour ferry trip where propane must be off.

Both panels have a 50 amp breaker at the top. The first has 2 the second has 1.

Thanks
Randy (N4TDT) and Karen Crete
Sarasota, Florida
SOLD:  2000 U270 34' WTFE Build 5756 "Ole Red"

Re: Electrical Load Distribution

Reply #1 –
Randy,

The first is the main 120 VAC breaker box.  Receives power from ATS which receives power from either shore power or generator.

The second one is supplied by the inverter.  The inverter also has a "pass through feature" so when it receives power from the inverter breaker on the main panel, it "passes it through" to all circuits in the second box.

And, yes, you can turn off any breakers for circuits you don't want powered. Probably only worth doing if not on shore power or generator.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Electrical Load Distribution

Reply #2 –
Quote from: floridarandy –
There are 2 - 50 amp distribution panels. Please help me understand why and what the difference is between them.

And, if I want my inverter to power only my refrigerator on AC (Dometic gas/AC) can I turn off the all the breakers except the one labeled refer?  We have an upcoming 18 hour ferry trip where propane must be off.

By default, the fridge is not powered by the inverter.  Nothing in the main breaker box is intended to run off the inverter (although it feeds the passthrough power to the inverter breaker box when you're on shore power).  There is, however, a second duplex outlet behind the fridge that runs off the inverter (and likely circuit #1 on your inverter breaker box since it's labeled "icemaker").

If you want to run the fridge off the inverter, you will need to open up the hatch on the outside of the fridge and plug the fridge into the other duplex outlet (one is white, the other brown and I don't recall which is which), then make sure the inverter is on. 
TEST THIS OPERATION BEFORE YOU NEED IT

Note that being an absorption fridge, running off 120 VAC it's operating a heating element.  That uses a lot more energy than a compressor/residential fridge would.  The 120 VAC element is basically replacing the function of the gas burner (it's a big calrod-type component).  If you have access to the coach for these 18 hours, watch your house battery voltage - it's going to put some strain on them.
Learn every day, but especially from the experiences of others. It's cheaper!  - John C. Bogle

2000 U320 36' non-slide / WildEBeest Rescue
2003 U320

Re: Electrical Load Distribution

Reply #3 –
When we were on the ferry from Nova Scotia to Newfoundland I just turned the refrigerator off and turned off the gas. It will keep things cold because it is not being opened. The 120 volt element will kill your batteries in short time. I don't think the batteries would keep it going for that long of a time.
previous 1984 35 ft ORED 250 HP 3208 Cat       
previous 1998 40 ft U295 CAI 325 hp Cummins
previous 2003 40 Ft u320 build #6140 450 Cummins M11.                                                         
1999 Mazda Miata
Ron, Nancy, Tipper the cat, Max The dog
1997 U 270 36 ft build number 5174 8.3 Cummins

Re: Electrical Load Distribution

Reply #4 –
When we had the lithium and Victron system installed it does allow us to run the fridge on the inverter if needed but we've only run it on gas when boondocking.

The 7 hour crossing dropped our 600ah by 132ah so I suspected the AC load is as stated by Michelle and Red Tractor. We're going to do some more testing before the overnight ferry later this month since that is estimated at 14-18 hours depending on crossing conditions. We think  did turn off all other AC loads as well as the salesman switch for DC.

Question:  Would the Uline ice maker (with water and ice turned off) take less power as a freezer substitute if we shut down the refrigerator?

Thanks

Randy (N4TDT) and Karen Crete
Sarasota, Florida
SOLD:  2000 U270 34' WTFE Build 5756 "Ole Red"

Re: Electrical Load Distribution

Reply #5 –
Randy,

Check and see if you can get some dry ice.  Doesn't take much to keep the freezer at temp.

Wrap in newspaper, etc a small piece for the top of the refrigerator section.

It evaporates (solid to gas), so no mess.  CO2 is not poisonous unless you decided to stick your head in the refrigerator where it is concentrated.

We did this all the time when sailing offshore to reduce refrigerator run time.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Electrical Load Distribution

Reply #6 –
I like Brett's idea of dry ice but if you can't find any and want to keep your fridge
cold, buy a bag of ice. I used that going to New Foundland, only I did the 6 hour
trip both ways and used the same bag of ice, keeping it my freeze between trips.
I didn't have anything in the freezer so I didn't have to worry about it.
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport