Operating Refrigerator on Inverter

[Deerhunter]

Greetings:
Due to the fact that MH fires started by the refrigerator are one of the biggest claims for Insurance carriers, I thought I would suggest an idea and see what others think about it.

First, I don't know how many amps the refrigerator draws in the AC mode and I have a large 4 door Norcold with an ice maker so this may be out of the question.

Second, assuming that a person doesn't want to operate their refrigerator on propane when traveling.

QUESTION - Instead of running the generator just to power the refrigerator when in AC mode, could the refrigerator run from a converter (DC to AC)?

[RV Wizard]

That would be an inverter. There are all electric coaches that do just that. Your refrigerator only draws about 3.5 amps until the ice makes is in harvest cycle. then it will jump up a few more for a couple of minutes. You would probably have to plug the refrigerator power cord into the receptacle marked "ice maker"; this would be power by inverter.

[NeilV]

I used an 800 watt inverter to do that in my prior coach and could run the 8 cu ft refridgerator all day long on a charge. I have an old computer UPS that works with external batteries and has its own transfer switch that I am considering setting up for that purpose in my current coach.

The problem with setting this up to be automatic is in getting the time delay relays that won't flutter when the generator shuts down or utility power gets interrupted as this can blow the inverter which is why I am considering the UPS or getting a RV inverter designed for this purpose.

[Deerhunter]

From Mike - RV Wizard:
That would be an inverter. There are all electric coaches that do just that. Your refrigerator only draws about 3.5 amps until the ice makes is in harvest cycle. then it will jump up a few more for a couple of minutes. You would probably have to plug the refrigerator power cord into the receptacle marked "ice maker"; this would be power by inverter.


Thanks very much for your reply.
My next question is since the ice maker is running on power supplied by the inverter then the refrigerator could be plugged into the same source as you indicated - do I select the AC mode on the refrigerator and just leave it there regardless of whether I am on generator or plugged in at a campsite's AC power?

[Gary RVRoamer]

A Norcold 1200 uses 660 watts (5.5 amps). There should be a sticker inside the right hand door giving you the 120vac and 12vdc power requirements.

Your Newmar may have been wired to provide inverter power to the fridge, icemaker or both. Typically just the icemaker, though. Move the plug to the icemaker outlet and leave the fridge in AUtomatic mode - it will select 120vac electric whenever available. That includes the inverter as a source.

Don't leave the fridge on the inverter for long on a hot day if the engine isn't running. That 660 watts will eat the batteries quickly. Switch it to Propane mode if you stop for an hour or so.

You would actually be better off swapping the Norcold for one of the new energy efficient residential fridges. They use less power than the Norcold 1200 and cool better.

[Deerhunter]

Quote:

Originally Posted by RV Roamer [Gary] A Norcold 1200 uses 660 watts (5.5 amps). There should be a sticker inside the right hand door giving you the 120vac and 12vdc power requirements. Your Newmar may have been wired to provide inverter power to the fridge, icemaker or both. Typically just the icemaker, though. Move the plug to the icemaker outlet and leave the fridge in AUtomatic mode - it will select 120vac electric whenever available. That includes the inverter as a source. Don't leave the fridge on the inverter for long on a hot day if the engine isn't running. That 660 watts will eat the batteries quickly. Switch it to Propane mode if you stop for an hour or so. You would actually be better off swapping the Norcold for one of the new energy efficient residential fridges. They use less power than the Norcold 1200 and cool better.

Hi Gary,
Thanks so much for the reply. You've answer all my existing questions and offered a suggestion for future consideration. I do appreciate the advice from you as well as all the replies from everyone.

[Bob Nuttmann]

Our coach is all electric and I like that a lot. We have a large fridge with an ice maker. Our coach came with a seperate inverter and 2 8D batts just for the fridge. Normally if you are boondocking you run the gen 2 hours a day to charge up.

[Deerhunter]

Quote:

Originally Posted by Bob Nuttmann Our coach is all electric and I like that a lot. We have a large fridge with an ice maker. Our coach came with a seperate inverter and 2 8D batts just for the fridge. Normally if you are boondocking you run the gen 2 hours a day to charge up.

Thanks Bob - is your 8D batts AGM, Gel, or flooded type batts?

[Tincup]

Deerhuinter,

I have a Norcold 1200 and run mine for 4-5 hours on my inverter. I have 6 T105RE batteries and 750W of solar and am currently in the So. Cal. desert.

I think there needs to be a bit of clarification on the amount of power consumed by the reefer. Remember the equation for converting Watts to Amps, (A = W/V). The reefer uses 660W at 120Vac, if you run the reefer from your inverter it will still use 660W but that power is provided by your batteries so, using the equation A = W/V we get 660W divided by 12V = 55A. That is a significant amount of power for your batteries to provide on a continuous basis. I don't know how many or type of batteries you have but this 55W is something you might want to consider.

[Bob Nuttmann]

Deerhunter our batteries are AGM.

[RV Wizard]

May I suggest that if you are concerned about a fire, that you simply put a fire suppression unit in the refrigerator compartment and run the refrigerator on LP gas mode. These type refrigerator has been around for hundreds of years and are for the most part very safe as long as you do not have a leaking gas line.

[NeilV]

When the engine is running there should be no problems with battery capacity however keep in mind that the refridgerator does not draw full current all the time as it does cycle on and off to maintain its temperature range. If you have the refridgerator already cooled down beforehand then you will not experience the same battery drain as if it was just being turned on.

As far as fires are concerned while they can be dramatic and may be caused by the refridgerator you may also find that lack of maintenance also plays a part too. If your fridge is well maintained and the cooling unit area kept clean and free of debris then you should not be at as high a risk as many others who just let the leaves and dirt build up. A fire suppressant system such as the Cold Fire System reference here on IRV2 on a number of occasions and by Mike just now may be a consideration.

[caymann]

1. Most refrigerator fires are caused because of the leaking coolant catching fire, not because of propane catching fire. Although at gas stations one must turn off the propane (if in that mode)

2. Most of the time, when this happens, the refrigerator was running on electric mode

[Deerhunter]

Quote:

Originally Posted by caymann 1. Most refrigerator fires are caused because of the leaking coolant catching fire, not because of propane catching fire. Although at gas stations one must turn off the propane (if in that mode) 2. Most of the time, when this happens, the refrigerator was running on electric mode

Hi Caymann,
I didn't know that - I was just quoting facts from Insurance claims as published in one of my RV magazines that I read.

Where did you obtain this info?