inverter power to fridge

[Rikadoo]

So I Have a question that the answer may be as plain as the nose on my face, that I first thought was inherent to just my rig however I have now run into a couple guys with the same question.

Why when you are using your inverter thats ONLY running off the batteries it will not power the fridge, my rig is a 2003 HR endeavor with a 2 way fridge, the other is a 2019 winnebago that has a house stye fridge. My reasoning is that due to the continual draw it would drain the batteries, I just figured that running down the road you could use the inverter then so not have to run the genny, Both fridges will run with no problem either on the shore power or the generator.

[birdshill123]

You need to see if there are 2 outlets behind your fridge. One should be for the inverter. Everyone runs the fridge from the inverter when boondocking or going down the road.

[Poppa G]

There should be 2 outlets where your fridge is plugged in,on my 2003 HR Imperial my top outlet is from your inverter,the bottom is on shore or generator power.Don’t forget to enable your inverter,your fridge will then run on the inverter and not go to LP.When done traveling just switch back to the other outlet.

[96 EVO]

27 minutes ago, Poppa G said:

 .When done traveling just switch back to the other outlet.

Like, soon after you stop if you don't have a shore power hookup!

The heating element in a absorption fridge draws far more power than a modern residential fridge compressor!

It will drain your house batteries quickly once you shut down your engine.

I don't bother. I just leave it in auto and let it run as designed, burning a bit of propane going down the road.

Edited May 20, 2022 by 96 EVO

[Rocketman3]

Here are some numbers…

when I had my Norcold 1200, if it was on 120v it used about 470 watts of power - and had very little cycle off time. When it was on LP, the watts were very low (I never measured them - but I would guess 12 to 18 watts).

My Residential Fridge (Fisher & Paykel) uses much less - I think about 80 watts - but it cycles down a lot more. 
 

converting both to 12v amps - The Norcold used 40amps. It will run on the inverter (if the plugs are set-up correctly) but it will drain (to the 50% level) the four 6v battery in 10 hours - if that was all that was running- in reality with lights on, etc. five hours and the batteries are completely empty. 

The residential uses about 7amps - with a lot more off-cycle time. Solar or generator for an hour in the morning and evening- will keep up with that demand. 
 

when I drove to Alaska, before I started each drive day - I would switch the Norcold to 120v - the alternator would keep it powered during the drive. I would switch it back to LP when the driving was done for the day. One day I forgot to switch it back - had to run the generator for a bit when I finally realized it. 

[Tom Cherry]

47 minutes ago, Rocketman3 said:

Here are some numbers…

when I had my Norcold 1200, if it was on 120v it used about 470 watts of power - and had very little cycle off time. When it was on LP, the watts were very low (I never measured them - but I would guess 12 to 18 watts).

My Residential Fridge (Fisher & Paykel) uses much less - I think about 80 watts - but it cycles down a lot more. 
 

converting both to 12v amps - The Norcold used 40amps. It will run on the inverter (if the plugs are set-up correctly) but it will drain (to the 50% level) the four 6v battery in 10 hours - if that was all that was running- in reality with lights on, etc. five hours and the batteries are completely empty. 

The residential uses about 7amps - with a lot more off-cycle time. Solar or generator for an hour in the morning and evening- will keep up with that demand. 
 

when I drove to Alaska, before I started each drive day - I would switch the Norcold to 120v - the alternator would keep it powered during the drive. I would switch it back to LP when the driving was done for the day. One day I forgot to switch it back - had to run the generator for a bit when I finally realized it. 

To add another twist.  Not all Norcold 1200 had TWO plugs, one for the heaters and one for the ice maker.  Therefore, after a certain year, circa 2000 or so….and don’t take that as exact, Monaco added two receptacles.  The breaker in the panel marked Refrigerator was NOT powered off the inverter.  The ice maker one IS powered from the inverter.  Thus to get AC from the inverter while driving, you either had to have a 2 prong, Y adapter for the ice maker or plug and unplug.

As to the power consumption….right on.  The batteries were never sized to provide AC to the heaters.  Bill Grove, Richard Smith and I, maybe others did some load studies on the Samsungs.  We also discussed consumption and batteries at one of the Gatherings.  Bottom line, if you have a two bank (Four total) House batteries, you can easily go 24 hours without totally depleting them.  This is from our wattmeter studies.  The rule of thumb is to run your Genny for 3 or so hours if boon docking or have the MH plugged in at night.  NOW, most of us replaced the incandescent bulbs in the overheads and under counters and such to reduce energy.  This also assumes you don’t really burn up power with other 115 VAC appliances.  It also assumes that you don’t make ice (the dump cycle has a heater).  AND, you use the “energy saving” setting…

So, bottom line, a Res Refer will work with a 4 battery, two bank set….as long as you recharge once per day and use good energy conservative practices.

[waterskier_1]

If your 2-way refrigerator is an absorption type (propane/110VAC), it was designed to quit using 110VAC when on the inverter because it is very inefficient.  They are best on propane, and if you set it to Auto, it will automatically switch to propane when there is no shore power or generator. 

  - Rick N 

[Dr4Film]

2 hours ago, Rikadoo said:

Why when you are using your inverter that's ONLY running off the batteries it will not power the fridge, my rig is a 2003 HR endeavor with a 2-way fridge, the other is a 2019 Winnebago that has a house stye fridge. My reasoning is that due to the continual draw it would drain the batteries, I just figured that running down the road you could use the inverter then so not have to run the genny, both fridges will run with no problem either on the shore power or the generator.

You are specifically referring to your RV type fridge and not residential.

Your RV fridge requires 12 VDC to power the control board along with 120 VAC to power the two heaters that heat up the solution. The fridge is plugged into a non-Inverter driven outlet for a specific purpose. When your generator is not running or you remove shore power the fridge now knows to switch over to LPG to keep the solution hot.

You can power the RV fridge off your Inverter anytime you want by removing the plug from the non-Inverter outlet and plug it into the Inverter outlet. BUT, making that choice comes with responsibilities and consequences. Your engine has to be running all the time. When you turn off your engine, you will need to access the rear of the fridge to remove the fridge plug from the Inverter outlet and plug it into the non-inverter outlet. If you don't your house batteries will drain significantly fast which puts a strain not only on the Inverter but more so on the house batteries.

I tried this once and when we stopped for lunch my house batteries were almost dead well beyond the recommended 50% SOC where you are not to let the house batteries go below before having them charged back to Float SOC.

Bottomline, I don't recommend doing that but it's your call, your coach, your batteries and your Inverter.

[1nolaguy]

My question is concerning the two outlets behind the fridge. The one that is connected to the inverter, is this wired through the GFCI in the bath? I ask this because therr were two 12g - 120v leads that came from my original inverter (Xantrex Freedom 2500). It appears that all 120v outlets use pass through power via the inverter unless they are wired through the main 120 breaker panel such as the washer/dryer, three outlets in the bedroom, A/C's, etc. From the two leads one feed directly to the microwave/convection oven. ALL of the other 120v outlets appear to go through the bath GFCI (which seems ridiculous in its own right but that is another subject). Ours is a 2005 Safari Cheetah. If it is not throught the GFCI is it tied to the same lead as the microwave?

[Tom Cherry]

2 hours ago, 1nolaguy said:

My question is concerning the two outlets behind the fridge. The one that is connected to the inverter, is this wired through the GFCI in the bath? I ask this because therr were two 12g - 120v leads that came from my original inverter (Xantrex Freedom 2500). It appears that all 120v outlets use pass through power via the inverter unless they are wired through the main 120 breaker panel such as the washer/dryer, three outlets in the bedroom, A/C's, etc. From the two leads one feed directly to the microwave/convection oven. ALL of the other 120v outlets appear to go through the bath GFCI (which seems ridiculous in its own right but that is another subject). Ours is a 2005 Safari Cheetah. If it is not throught the GFCI is it tied to the same lead as the microwave?

The ONLY away to answer that question is to do some testing.  TYPICALLY, at least in 2007 and up on the Camelots, there are, as you pointed out….TWO AC feeds.  On the Magnums, there are TW0 20 amp pin circuit breakers.  The Inverter is typically fed from a 30 A CB in the main panel.  Some inverters have an incoming pin style circuit breaker for the feed.  If you have a GFCI Receptacle in the hall area near or under the sink, it CAN control the NON Microwave feed.  Circuit ONE from the inverter goes directly to the Microwave.  It is a dedicated, and NEC/RVIA approved NON GCFI feed.

The OTHER circuit goes directly from the Inverter into the GFCI Receptacle.  It is a 20 Amp GCFI and should have the side slot that differentiates it from a 15 A circuit.  It will be fed with number 12 Romex.  Mine was like that.  The inverter was almost under that area and the run was short.  BUT, I took it out and did some tracing.  There were TWO feeds or loads on the GFCI.  One went to all the receptacles around the sinks…which is NEC Code.  The other feed or Romex sent to the Icemaker receptacle in the rear outside compartment where the refrigerator (a Dometic Gas/Heater Element was.  The ISSUE.  On a cold night out in NM, the receptacle would have condensation when it warmed up.  Bingo, the GFCI would panic and shut down.  That killed all the other circuits.  The GCFI was 5 years old….and I replaced it.  BUT. I ran the icemaker feed and the other circuits (Awning and maybe the HE Center) off the LINE IN or Non Protected side.  The sink outlets and others were protected.  I never had a blip since then.

When i replaced the Dometic with a Samsung Res Refer, it worked fine.  I plug into the icemaker receptacle and rarely use the heater (20 amp) receptacle.

So, until you have a wiring diagram or pull out the GCFI and experiment, assuming you have TWO Loads or down stream circuits, you never know.  You do NOT want to run your Res Refer on a GFCI circuit..  Your home "refrigerator is fed from a dedicated circuit or breaker….and it specifically (NEC) does  NOT have a GFCI a breaker….nor does your microwave.  That is NEC Code…and has been for at least 30 years…