Residential Fridge Wiring

[grashley]

I FINALLY got the old fridge out of my 2016 Sunstar! On mine there were FOUR screws in the bottom front of the fridge. Two were obvious. The other two were just in small holes covered by c#@?.

On to the next challenge. I have looked at the wiring diagrams. They might as well be written in greek. How do I get INVERTER power to the fridge? It is on its' own circuit, I believe. The fridge sits directly on top of the 120 VAC panel. I found no inverter power in the panel enclosure. The fridge, the outside radio, just below the fridge, and the receptacle beside the power panel are all NOT on the inverter. Four bedroom outlets and two front outlets - TV and beside passenger seat - are on the inverter.
It appears the inverter is kind of below the fridge. Do I drop down there and find a place to connect? Are there inverter wires behind the power panel?

At this point, I can get it into the cabinet hole. I have not figured out how to get inverter power to it.

Thanks in advance for all the good advise.

 

[8Muddypaws]

Might be easier to add another inverter that only powers the refrigerator.

 

[Boat Bum]

Can't you leverage one of the outlets on the inverter and use that to power the fridge?

 

[John Canfield]

Gordon, how many watts is the inverter? Not all residential fridge compressors are happy running on modified sine wave inverters. MuddyPaw's comment about installing a second inverter might be the better idea, you could buy a pure sine wave model but that has its own wiring challenges as well.

I don't have time to look at your wiring diagrams this morning but maybe later today. We have some good talent here with wiring diagrams so maybe one of them will beat me to it.

 

[grashley]

It is a 1000 watt inverter. The fridge pulls 297 kWh / yr, or 33 watts / hour.
Boat Bum: I think I have identified an inverter wire below the fridge. I will check it today before I connect to it. That would be a simple connection.

John: How do I tell if the fridge is unhappy on modified sine wave power? While more difficult and expensive than connecting to the current inverter, the batteries are only a couple feet from the fridge and power center.

 

[John Canfield]

...snip...John: How do I tell if the fridge is unhappy on modified sine wave power? ...snip...

It's about the induction motor in small appliances, as far as being unhappy you wouldn't know until the motor overheats and eventually fails. Here's a good explanation of the technical aspects.

Our Itasca Horizon was only a month or two old when I started the upgrades. First on the list was replacing the MSW Dimensions inverter (also known as the Demented ) with a pure sine wave Xantrex.

 

[grashley]

Let me further muddy the water.
One wire behind the power panel was labeled with brown tape. Taking off the wrap, the wire itself was labeled 2015 E307?? 78 From 2 18400 ?? Throw In #2

The best I can tell, this wire runs from a connector from the inverter (I believe it is right behind the power panel) and to LR TV area. Ref 120V body wiring diagram # 189352 Sheet 6 location C3. I also do not understand how the wire to the bedroom RCP can branch off BEFORE the inverter and still be powered by the inverter, which they are.

I cut a small notch in both sides of the insulation to test for power and to verify it was indeed on the inverter circuit. While notching the hot side, with my arm resting on the power panel, I got a VERY clear indication it was hot. Tingle. When I test it with the VOM - dead. Shore power, inverter on, dead. No circuits blown (VOM verified power). All inverter rcp work on shore power. All 120V circuits seem to be working.

Since I do have battery cables and the fridge power cable already in the compartment, maybe the second inverter is the way to go?

 

[John Canfield]

Now I understand the problem digesting your Winnie wiring diagrams, my former Horizon wiring was fairly straightforward unlike yours. Anyway... I looked over the 110V Load center PDF wiring and noticed something on location C-8:

MODULE-CONTROL,PCS
174295-03-000
DETAIL DA

Do you know what the PCS Control Module is? The fridge 110V is hooked up here. I have no idea what this thing does.

I now think the easiest way forward is a separate PSW inverter for the fridge. Get the fridge you want and determine its max current load which would probably be if the fridge was in a defrost cycle (or ice maker popping out cubes, etc.) and size the inverter. The Frigidaire (19 cu ft as I recall) myself and a buddy installed drew very little run watts but I forgot the numbers unfortunately.

 

[grashley]

John Your help is invaluable! Thank you so much. While it does not help me learn to read these diagrams, it is comforting to know the expert is not comfortable with them either.

I believe the PCS is part of the power management / load shedding system. Most model 30T are 30A, thus need the load shedding. Ours has the 50A option, but still has the load shedder.

 

[John Canfield]

You are quite welcome but I don't consider myself an expert, just a garden variety hack . Given enough time both of us could probably come away with a good working knowledge of your AC wiring. One huge advantage of buying a Winnebago motorized RV is the excellent documentation - plumbing and wiring diagrams, etc. I don't know if towables have the same of wiring/plumbing diagrams.

Even with your Sunstar having the 50A option, you will of course still need load shedding when you're on 30A service but the fridge would/should be last on the list to shed. I don't remember if the fridge in our Horizon was even configured to shed.

 

[grashley]

I believe I have finally figured out how to do this. We have a trip to Panama City Beach in two weeks for our granddaughter's softball tourney. For that trip, I will simply plug into the existing outlet, and the fridge will run with shore power or generator. IF I need inverter power, I ill run a heavy extension cord under the fridge to that plug, and to a bedroom rec which is on inverter power.

If I want something better, other than getting my existing Li batteries installed, I will install a new 1500W - 2500 W inverter in the space behind the power center, below the fridge. I can fairly easily pull power from a new battery cable, then wire both the fridge and the GFCI receptacles (Kitchen & Bath) out of the inverter.

My next project: installing the Li batteries. I will start a new thread. I know there is more to it than just replacing the batteries. I will do some research before asking questions.

 

[John Canfield]

A 2+Kw Inverter is going to draw some serious amps of course so be sure and plan for the proper wire gauge considering the length of the run. You will need some kind of fuseable link or fuse close to the battery. Blue Sea has high quality low voltage supplies, it's my go-to for all things 12V.