swapped 3 way for ac frig.

[SusieQ]

The 3 way frig did not work in my 89 Falcon. I already had a large dorm frig with 2 doors which had fit perfect in one of my big trucks. I did some cabinet cutting and got it installed in my van. When plugged into shore power it works perfectly but my dream is to dry camp all the time. I had an electric wire ran to the old frig as well as a plug in that cabinet. I really thought I could make the old electric supply which had current off batteries work to power new frig. I am so disappointed it didn't work and I don't know what to do to make that new plug in work. Any ideas please?

My plan b to use this frig is to install my 2500 watt inverter. Batteries are 2 big sealed 92 ah under couch on right side. Frig is on left side of van. I didn't want to use such a big inverter or run cords across my floor.

Thanks for all the great information on this site it has been such an inspiration and learning tool.
Susan

[rjf7g]

Have you tested to voltage across the "old electric supply" from your batteries? It should show 12ish VDC. Install your inverter to this supply and test the output. You should get 110ish VAC. AC appliances like sine waves - your converter may be a modified sine wave converter. The health of your newly installed old dorm fridge may be at risk as the AC current produced by your inverter may not run the compressor and can burn it up. Some fridges will run fine and some will not - it depends on the specifics.

What did you do with the propane line that ran to your old 3-way fridge?

[booster]

Does the Falcon even have an inverter in it? Even if it did, the 110 power to the frig would likely be shore power only, if the frig has it's own 12v input. You may just need to find an outlet that does run off the inverter, if there is one.

Two 92AH batteries running a dorm frig through an inverter are not going to give you a lot of run time when off grid, I think. Even the most efficient 12v frigs use between 20-50 AH per day depending on conditions. Yours use could be as much as double that, depending on the frig and inverter efficiency. It would be good to check the amp draw while it is running and see how much 12v power it is using.

[SusieQ]

That propane line is capped off and leak tested. The idea of using it for running a propane buddy heater is being tossed around only if I can install a cut off in that line in that compartment behind frig. Factory didn't have one in it.

The reason I had to go up to that 2500 watt inverter is that frig needed one that big.

I know very little about ac/dc currents and I was wishful thinking I guess. I thought even if the power came from the batteries it went through the factory fuse box which converted that line to ac just for the frig. I asked my nephew to check that wire and he said it showed 110.

Yes Booster thank you, I was going to time it from full batteries and either add 2 more batteries or get an idea how often I need to run a generator.
This old unit didn't have a plug in that worked off battery power only one dc plug by the frig. but my nephew said that one wire to old frig was ac current but Im thinking he was wrong.... he is a great car painter not electrician though.

[markopolo]

Short reply:

Expect maybe 1 day fridge cooling if using the inverter. In this situation, when recharging I'd use both the van engine and the generator (both running at the same time for a while) . I'd start the van engine first so that there's plenty of current available to start the generator just in case your house batteries are low. Maybe 15 min van engine plus 1 hr of generator would get your batteries back to 90%. Might take longer as it depends a lot on the capacity of the charger in your van.

Long reply:

With the new fridge being AC 110v only so you'll need to be plugged in to utility grid power or use an inverter as previously noted.

Can you post a clear photo of the wires? We might see which looks like AC and which looks like DC.

For a reference point, I looked up the specs on a 3.1 cu ft 2 door Danby compact fridge/freezer. http://www.energystar.gov/productfinder ... ls/2215465
Daily power use of reference fridge: 874wh
Your 92ah (at 50% useable) could provide 1,127wh (92ah x 12.25v*) *50% SOC shows as 12.25v on some charts.

You should be able to power that reference fridge for full day. The efficiency of fridges vary greatly though so use the numbers for your particular fridge. A more effecient fridge and deeper discharge of the batteries might allow for two full days. That could be hard on the batteries though and lead to early replacement.

If there is a DC wire where the old fridge was installed it is likely way too small for a 2500w watt inverter. The 3-way fridge in my van uses approx 10a DC when running on AC from the inverter. I suspect that is much more than a 110v compressor fridge would use. 10a x 12v = 120w.

A 500w inverter might be sufficienct for a small 110v compressor fridge - someone else could help out here by commenting on the compressor start up loads - would it be more than 500w?

If using the 2500w inverter then it should be installed near the batteries, preferably in an adjacent compartment avoid corrosion or risk of sparks etc. Use suitable size large wiring.

For the fridge, I would use a inline automatic transfer switch: topic - http://www.classbforum.com/phpBB2/vi...php?f=9&t=2005 (approx $50)

The inline automatic transfer switch I used came with good instructions.

Note: I'm not suggesting you do it yourself if not qualified.

On the transfer switch:
"AC Input 2 from Utility" would connect to the breaker for the fridge in your AC panel. Wires to fridge, (hot/neutral/ground) would be disconnected from the panel.
"AC Input 1 from Inverter" would plug into one 110v outlet on the inverter
"AC Output to load" would connect to the hot/neutral/ground AC wires leading to fridge that were previously disconnected from the panel.

Again, I'm not suggesting you do it yourself if not qualified. Too risky.

The inline automatic transfer switch senses when you plug into AC power and would power the fridge with utility or grid power. When your van is not plugged in the fridge would be powered by the inverter (if the inverter is turned on). Remember to turn off the inverter to avoid draining your batteries completely when not powering the fridge. The alternator in your van should easily power the fridge while driving assuming your two house batteries are being charged by it.

Using an inline automatic transfer switch, Power for the fridge would route like this:

Batteries only: house batteries -> inverter -> inline automatic transfer switch -> fridge.

Engine running: engine running -> alternator -> isolator -> house batteries -> inverter -> inline automatic transfer switch -> fridge.

Plugged in or on generator: AC panel -> inline automatic transfer switch -> fridge.

[booster]

As Marko says, most of what you are probably in need of are beyond DIY if you have little knowledge of the systems and wiring. Adding to that is that the van is 25 years old, so it likely does not have the same parts in it as it did new, which makes guessing what to do difficult.

If you can find someone who is up on 12 volt systems to just track down and document what is there and roughly how it is wired, you would have a good place to start. With that information, this site is full of folks that will be able to help with recommendations of how to move forward. Perhaps the nephew, as he is a painter, may know some techs or audio types that could do it for a small fee, or beer. I think it would be worth it for you. Maybe someone on here lives close enough to take a look for you.

Safety has to be the prime consideration in all of it, so knowledge is good.

[SusieQ]

I will try to take pictures of this today and post them. My other ones are too big to post it says.

[SusieQ]

Thank you all very much. So now I have a plan of action I feel so much better. I have hooked up my inverter in a truck and then removed it from that truck after I watched a mechanic do it once. It has huge wires like 2 or 4 gauge. I will get it all installed except the battery connection and get an automatic transfer switch then seek out someone with experience to hook both these up. It will make life so much easier if it switches over automatic when plugged in. Should I get a digital readout hooked to batteries or just watch the one on the wall says its half power then I run the van and generator?

Now the choice of putting inverter in the little slide out pantry at end of couch or under the couch mounted to that pantry wall? My nephew helped me with the couch the way it folded over and made a bed was very neat but not workable for me to open the frig or move around when couch was in bed mode. After the adjustments we did the bed now raises up for me to work under it instead of laying on the floor and those few inches I can now open frig and walk sideways beside the bed. The water pump is under there and im not sure what the risk is of water spraying from that on the inverter. Thinking if I make hole in wall beside batteries under couch and run the inverter wires into pantry I can pull out pantry and turn inverter off and on and keep it up higher and away from any water source.

[SusieQ]

Marko you explained it very good im just a hard learner on this. I had notes from a previous post somewhere I had coffee that day and got my figures on frig and my calculator out. I did use that and rounded up and padded it. That's where I got the notion that these 2 batteries at 92ah each may work with some charging every day. Im on the right path and can add 2 more of these if needed.

The automatic transfer switch will need to be close to the inverter looks like a short cord that plugs into inverter. Two more cords on transfer switch. One cord will hook up to the van fuse box which will make it have power when plugged into shore and the other cord goes to the frig will have power from the shore first or inverter second. So I have to run those two cords across van to frig side. Since my frig has a plug in type cord will they cut the plug off and wire that to the power supply cord from the transfer switch or run the power supply to a plug in behind frig and just plug frig into it?

So the thinking to just run the frig cord over to the inverter plug in frig and always let it run off inverter wont work because when the van is plugged into shore power the frig will be pulling power out of batteries faster than the shore power puts it in the batteries?

[markopolo]

Your idea should work.

The transfer switch is optional. My thought for using it was to make the AC/DC DC/AC switchovers automatic. I hadn't thought of leaving the fridge plugged into the inverter all the time even when plugged in.

When the van is plugged in the converter/charger in the van should have have more than enough output to run the fridge through the inverter.

I don't think the fridge will pull more power from the batteries than what shore power (through the converter/charger) can put into the batteries.

Try your idea first to see how it works. Also, try to find the model number on the converter/charger in the van. I'd be happy to try to find the specs on it to get an idea of its output.

Also, if you have the manual for the inverter see if it mentions anything about fridges. rjf7g mentioned this potential issue above. Some modified sine wave inverter manufacturers list fridges as items that do work. It seems to depend on the quality of the inverter.

[SusieQ]

I went back a read again. Yes rjf7g it is a modified sine inverter a roadpro RPPI 2500. I trusted it more to charge my laptop after I got a certain power strip that had fuses and is suppose to help regulate the stream to be safer for electronics I always hook my electronics only in that cord and plugged frig directly in other spot and that left one plug on inverter if I did run coffee, toaster oven, electric skillet or microwave I would unplug the frig and plug in my other appliance just long enough to cook and then put frig right back in. I ran a small crock pot a lot I would unplug my electronics strip and run it on low it sat in the floor in a basket surrounded by towels while I drove it cooked up my food really easy. I think my old1800w inverter was not even modified that was my problem and I gave it away and told them I don't think its good for any frig. they were gonna use it for tv dvd.

Thank you for asking me about the gas line. I am scared of propane because I have never used it except a outdoors grill. I know the 2 cooktop eyes do work but have not gotten to the heater yet it just don't work so far don't know why. I think its so small a space that maybe easier to hook up a buddy heater to that frig line sit it on the cooktop that's what I have done so far with a tiny ceramic heater that plugs in. keep the installed factory propane full and use the little gas cooktop so I will have less need for battery charging.

Marko I know the van has a Magnetek 6300A fuse panel. It has 2 15 amp breakers one says frig. I get some buzzing at times from it and have to flip breaker off then back on that was even before I changed the frig out. I hope to work around this or replace it for couple hundred.
Anything you can tell me about this thing would help.

[markopolo]

re: the buzzing - You could get an electrician or someone who knows enough about AC electrical panels to check for loose wires, loose breaker or failing breaker.

I don't think you'd need to replace the panel. You could upgrade the converter/charger portion of it at some point. Here's some info: http://www.bestconverter.com/MagnetekPa ... _c_64.html

Useful file to download here: http://www.hayseed.net/~jpk5lad/RV%2...%20Binder1.pdf for info about the Magnatek 6300 series.

The Magnatek converter when plugged in should be able to supply more than enough current to the Roadpro inverter to power the fridge if you are still planning to use it that way.

[g1g]

I'll go along and say that a modified invertor won't run a fridge. You need a true sine wave one then mount it close to the batteries.