Inverter for fridge

[Chateau_Nomad]

I didn't find a specific "how to" thread about this...

I'm in the process of buying a 1,000 watt inverter specifically to run two items... the two-way absorption fridge and a video projector (new addition to eliminate the two TVs). We may occasionally plug in a laptop computer.

http://Limited-time deal: BELTTT 150...X60ZN2GXCPANZW

I'm thinking of mounting the inverter under the kitchen sink area, which is about two feet from the batteries. It has a remote switch, which is convenient.

I'm trying to keep this project "budget", so no automatic transfer switch. I'm going to run a couple outlets for the projector... one near the front, and another to the rear bedroom.

The issue concerns the refrigerator, and how to wire an outlet for it without a transfer switch. I'm thinking about installing a dedicated inverted outlet in the cabinet above the fridge (where the microwave outlet is), then switch the plug to either the regular (shore/generator outlet) or the inverted outlet as desired.

Is there another less convoluted way to do this without breaking the bank? I don't mind the occasional hassle of plug/unplug, etc... just wondering if I'm missing something simpler?

[16ACE27]

Unplugging/plugging is about as simple as it gets. When we added an A/C to the bedroom we added a new receptacle next to the installed receptacle behind the TV and wired the A/C plug to that location. Gives us the option to run the bedroom A/C off the standard house AC circuit, or a dedicated AC circuit to a separate 30 A outlet next to the original 30 amp outlet outside.

[OldWEB]

Originally Posted by Chateau_Nomad

I didn't find a specific "how to" thread about this...

<SNIP>

Is there another less convoluted way to do this without breaking the bank? I don't mind the occasional hassle of plug/unplug, etc... just wondering if I'm missing something simpler?

If you do not mind a bit of wiring, install a DPDT switch, this one from Amazon is rated 20A, maybe get a couple, or find similar elsewhere.
Just wire the reefer to the center two; SP on one side, inverter on the other, not that it matters but just keep 'hots' on one half and 'neutrals' the other half.
Install all in a switch box with a cover plate with a hole in it for safety and mount it also under the sink.

W/screws
Cheap deal
$$$$$

[Chateau_Nomad]

Originally Posted by OldWEB

If you do not mind a bit of wiring, install a DPDT switch, this one from Amazon is rated 20A, maybe get a couple, or find similar elsewhere.
Just wire the reefer to the center two; SP on one side, inverter on the other, not that it matters but just keep 'hots' on one half and 'neutrals' the other half.
Install all in a switch box with a cover plate with a hole in it for safety and mount it also under the sink.

W/screws
Cheap deal
$$$$$

I like that idea! Curious as to why mount it under the sink? I could probably mount a box in the cabinet over the fridge. But you might not know the layout of my rig... Thanks for the idea!

[Kvrgvr]

Originally Posted by OldWEB

If you do not mind a bit of wiring, install a DPDT switch, this one from Amazon is rated 20A, maybe get a couple, or find similar elsewhere.
Just wire the reefer to the center two; SP on one side, inverter on the other, not that it matters but just keep 'hots' on one half and 'neutrals' the other half.
Install all in a switch box with a cover plate with a hole in it for safety and mount it also under the sink.

W/screws
Cheap deal
$$$$$

If you do use a DPDT switch, you may want power off when you switch. Electricity likes to hang on to the last thing it was hooked to. It will arc when disconnected. Eventually it will burn up the switch. Just saying.

I'm planning the same thing. Like you, low tech. Plan to run 12 gauge cord through the walls to the frig. Manually change plug at the frig.

Good luck on what you choose.

[DavidEM]

All of the above suggestions should work. But why would you want to run an absorption fridge off of inverter power? Absorption fridges on AC draw about 250 watts. That will take about 20 amps DC and unless you have a big battery bank will draw them down quickly. And how are you going to recharge it?

Why not run it on propane? An absorption fridge uses roughly a pound of propane each day.

David

[16ACE27]

Originally Posted by OldWEB

If you do not mind a bit of wiring, install a DPDT switch, this one from Amazon is rated 20A, maybe get a couple, or find similar elsewhere.
Just wire the reefer to the center two; SP on one side, inverter on the other, not that it matters but just keep 'hots' on one half and 'neutrals' the other half.
Install all in a switch box with a cover plate with a hole in it for safety and mount it also under the sink.

W/screws
Cheap deal
$$$$$

This is what I did for my inverter output for the circuit it supplied (TVs and some outlets) but I could never train the wife on how to use it so I ended up replacing it with an external ATS:
https://www.amazon.com/gp/product/B004S5Y158/

For $56 it is well worth it.

[Trkyte@msn.com]

My rig has a dedicated 100 watt inverter for the TVs. I tapped off this and ,ran a circuit to the refrigerator. I only use it when my trip routes via bridges and tunnels so I ,can turn off the propane and stay half way legal

[16ACE27]

Originally Posted by Trkyte@msn.com

My rig has a dedicated 100 watt inverter for the TVs. I tapped off this and ,ran a circuit to the refrigerator. I only use it when my trip routes via bridges and tunnels so I ,can turn off the propane and stay half way legal

What fridge do you have that the electric heating element is under 100 watts?

Or did you mean 1000 watts?

[Trkyte@msn.com]

meant 1000watts.

[mstng]

Originally Posted by DavidEM

All of the above suggestions should work. But why would you want to run an absorption fridge off of inverter power? Absorption fridges on AC draw about 250 watts. That will take about 20 amps DC and unless you have a big battery bank will draw them down quickly. And how are you going to recharge it?

Why not run it on propane? An absorption fridge uses roughly a pound of propane each day.

David

Agree, one of my biggest disappointment is the A/C or battery Refer and induction stove. Propane for both would run for weeks. My 200 ah batteries provide about an hour of cooking. Be happy you have propane unless you have 600 ah of lithium

[Travelin' Texans]

Originally Posted by DavidEM

All of the above suggestions should work. But why would you want to run an absorption fridge off of inverter power? Absorption fridges on AC draw about 250 watts. That will take about 20 amps DC and unless you have a big battery bank will draw them down quickly. And how are you going to recharge it?

Why not run it on propane? An absorption fridge uses roughly a pound of propane each day.

David

Was curious also?
If your not constantly fanning the fridge doors open/closed a 30# bottle should last 30-45 days.
Running the fridge on 120 through an inverter might last 4-5 days depending on what type & what condition the bank of batteries.
Why rebuild something that ain't broke? Enquiring minds want to know!

[Buckweet]

I had a residential fridge installed in our coach . Have to say it was the best thing that we did to the mh... much better refrigerator and we had it installed , bought the frig at lowes and the rv firm put it in the mh and installed the inverter. Never did like the norcold frig just woould not keep up and we had it serviced etc to no avail .. with just the two of us it still would not go below 37 degrees. and we just did not want to take the chance any longer . Most of the time it was near 40 took and took a long time to recover if you open the doors looking for a slice of cheese or something

bite the bullet and put in a res frig have a rv dealer install it and show you now to run it . never bothered our batterys even when we dry camped . we rand the genset for an hour , shut it down when we hit the sac and the frig was ice cold in the am

Just remember to turn on the inverter when not plugged into shore power turn it on when traveling

cost to us at the time was about 1400 bucks , no more spoiled food and much colder beer ! they sold our old one to some folks that did not use the gas feature

Just my twocents worth

[Hittntherooad]

Most absorption fridges work fine if installed correctly. I had to add a couple fans to get the heat out of mine. Just did 5 weeks in the Keys. Had 2 degrees in the freezer and 32 to 34 in fridge on gas and electric.

[OldWEB]

Originally Posted by Kvrgvr

If you do use a DPDT switch, you may want power off when you switch. Electricity likes to hang on to the last thing it was hooked to. It will arc when disconnected. Eventually it will burn up the switch. Just saying.

I'm planning the same thing. Like you, low tech. Plan to run 12 gauge cord through the walls to the frig. Manually change plug at the frig.

Good luck on what you choose.

You are thinking of DC... that is an entity of its own when trying to switch it for which you need DC rated products. The OP is talking AC and a few AC amps will be no problem with a 20A switch plus the fact AC power goes through zero volts 120 times a second reduces the arcing and I suggested the DP switch for that way you break the current on two legs (also I was not sure on trying to tie the inverter and SP neutral together) ...trust me.

[Chateau_Nomad]

My intent for the absorption reefer is run off inverter while rolling. No switching off reefer at fuel stops (yep I do that). Between the alternator and solar (obviously when sunny) would help keep batteries topped up, or at least not overly drained.

The other intent is a small projector for a couple hours of TV/movies/streaming in evenings. If we were boondocking I would definitely run reefer on propane.

Yes, I understand that propane goes a long way running JUST the reefer, but we also use propane for the stovetop and occasional furnace for chilly nights... and don't forget about the hot water tank - which together can suck a propane tank dry pretty quick.

So, I figured batteries are replenishable... why not take advantage of that. And cheaper than the rising propane price. There's also the generator, which sips a little more than 1/2 gallon per hour. To me, that's even cheaper than propane when you calculate the convenience factor of finding gasoline vs propane on the road. Just some random thoughts...

[Chance]

Originally Posted by Chateau_Nomad

My intent for the absorption reefer is run off inverter while rolling. No switching off reefer at fuel stops (yep I do that). Between the alternator and solar (obviously when sunny) would help keep batteries topped up, or at least not overly drained.

The other intent is a small projector for a couple hours of TV/movies/streaming in evenings. If we were boondocking I would definitely run reefer on propane.

Yes, I understand that propane goes a long way running JUST the reefer, but we also use propane for the stovetop and occasional furnace for chilly nights... and don't forget about the hot water tank - which together can suck a propane tank dry pretty quick.

So, I figured batteries are replenishable... why not take advantage of that. And cheaper than the rising propane price. There's also the generator, which sips a little more than 1/2 gallon per hour. To me, that's even cheaper than propane when you calculate the convenience factor of finding gasoline vs propane on the road. Just some random thoughts...

Convenience and lower energy costs are two very different subjects.

If you rarely used propane for anything other than fridge, I could see a significant improvement in not having to fill propane as often, but the items you mention like cooking, furnace and hot water are so much greater than what the fridge uses that to me it seems like the proverbial drop in the bucket. Would you even notice the difference in how often you refill?

I can relate to not wanting to refill propane because sometimes it’s really inconvenient and takes way too long. Having said that, if you will be refilling nearly as often anyway, does it matter much?

From operating cost standpoint, energy has to come from somewhere, so though batteries are “replenishable”, there is an added cost to keep them charged.

Ignoring solar contribution since it’s probably already used (needed and or committed) for other loads, energy has to come from vehicle gas tank or shore power. “Free” shore electrical power is a simple choice most of us take advantage of, but if you have to generate electricity via alternator while driving, or run generator, is cost lower? It would take a while to estimate that, requiring a lot of data.

You mention generator at 1/2 gallon per hour being cheaper? If you run generator SOLELY to power fridge on electricity, you’d be wasting a ton of money compared to propane. If you were running it anyway to power air conditioner or something else, then additional costs in gasoline are much less, but since not free, may be more than cost of propane.

Sounds like you will add inverter regardless to power projector, which may add some convenience by reducing fridge dependence on propane. However, my 2 cents is that fuel cost savings will be very little if any. Campers who boondock frequently may end up spending much more on gas than what they save on propane, so I recommend you proceed with caution.

[Chateau_Nomad]

Originally Posted by Chance

Convenience and lower energy costs are two very different subjects.

If you rarely used propane for anything other than fridge, I could see a significant improvement in not having to fill propane as often, but the items you mention like cooking, furnace and hot water are so much greater than what the fridge uses that to me it seems like the proverbial drop in the bucket. Would you even notice the difference in how often you refill?

I can relate to not wanting to refill propane because sometimes it’s really inconvenient and takes way too long. Having said that, if you will be refilling nearly as often anyway, does it matter much?

From operating cost standpoint, energy has to come from somewhere, so though batteries are “replenishable”, there is an added cost to keep them charged.

Ignoring solar contribution since it’s probably already used (needed and or committed) for other loads, energy has to come from vehicle gas tank or shore power. “Free” shore electrical power is a simple choice most of us take advantage of, but if you have to generate electricity via alternator while driving, or run generator, is cost lower? It would take a while to estimate that, requiring a lot of data.

You mention generator at 1/2 gallon per hour being cheaper? If you run generator SOLELY to power fridge on electricity, you’d be wasting a ton of money compared to propane. If you were running it anyway to power air conditioner or something else, then additional costs in gasoline are much less, but since not free, may be more than cost of propane.

Sounds like you will add inverter regardless to power projector, which may add some convenience by reducing fridge dependence on propane. However, my 2 cents is that fuel cost savings will be very little if any. Campers who boondock frequently may end up spending much more on gas than what they save on propane, so I recommend you proceed with caution.

Good points! Powering the projector is the primary goal; the refrigerator is secondary. What often happens is when I stop to refuel and shut off propane to the fridge, I forget to turn it back on... which for a few hours being off isn't really a disaster. But I figure since the inverter is there already, why not wire it in and use it?

If the inverter is wired to power the fridge, all I need to do is turn on the inverter, and the fridge will automatically switch from propane to electric - so it's a convenience factor there.

We tend to avoid VERY hot camping weather... and are often in the mountains. So boondocking A/C or furnace use (and resulting generator) are very infrequent. Solar tends to keep the batteries topped up, and if not, the generator runs a few hours pf needed... but that's rare.

All things considered, the fridge would primarily run from propane while boondocking, with possible breaks when the inverter is on. It will be a fun experiment to see how much draw the fridge alone has on the batteries while boondocking.

[taylorbob1]

I have an aftermarket inverter with auto transfer switch wired thru my breaker box so that it’s integrated into the Non-GFI outlet line.
Controls TVs, three outlets and the absorption fridge.
I also have a 300 watt solar array.

That said, I only use the inverter to power the fridge while driving.
Once at my destination, I either plug-in to shore power (the auto transfer switch immediately turns off inverter) or use propane mode while boondocking.

Here’s a good thread with my post and link to see wiring diagram.

https://www.thorforums.com/forums/f1...ter-21654.html

[Chateau_Nomad]

Originally Posted by taylorbob1

I have an aftermarket inverter with auto transfer switch wired thru my breaker box so that it’s integrated into the Non-GFI outlet line.
Controls TVs, three outlets and the absorption fridge.
I also have a 300 watt solar array.

That said, I only use the inverter to power the fridge while driving.
Once at my destination, I either plug-in to shore power (the auto transfer switch immediately turns off inverter) or use propane mode while boondocking.

Here’s a good thread with my post and link to see wiring diagram.

https://www.thorforums.com/forums/f1...ter-21654.html

Your scenario pretty much describes what I'm wanting to do. I have 200 watts on the roof.

A few clarification questions...

So you basically spliced the inverter between the "non-GFCI outlets breaker" and the outlets?

You mounted the inverter in close proximity to the electric service panel?

What gauge wire did you use for the 12v connection between 12v buss / ground bar and inverter? I'm guessing that was a pretty short distance?

The inverter in the vid is no longer available... is the switch generic?