Running Refrigerator off Inverter?

[scirocco22]

I know this has been discussed but I'm not having much luck searching for the thread that talked about this.

I know my refrigerator works off the inverter. I found that out by leaving the refrigerator on "au" and accidentally leaving the inverter on when at the dealer getting some work done.

The tech comes out and "reprimands" me for leaving the inverter on because he said the refrigerator instead of going into the propane mode, was using the "ac" mode off the inverter and it drew down the batteries to an unsafe level. I didn't get why he was so concerned because won't the inverter shut off before it draws the batteries all the way down?

Anyway, my real question is, why is it not recommended to run the refrigerator off the inverter while traveling down the road? I know there have been many threads on "to use" or"not to use" propane for the refrigerator while on the road but why isn't using the inverter recommended? Since the engine is running, there shouldn't be any battery problems using the inverter while on the road, should there?

Thanks.

<span class="ev_code_BLUE">edit: sorry folks, I put in the wrong search parameters. I now have found several threads discussing this. I am at this moment reading through them to see if I can find answers to my question. However, if anybody wants to chime in on this thread, please feel free to do so!

Thanks!</span>

[scirocco22]

I know this has been discussed but I'm not having much luck searching for the thread that talked about this.

I know my refrigerator works off the inverter. I found that out by leaving the refrigerator on "au" and accidentally leaving the inverter on when at the dealer getting some work done.

The tech comes out and "reprimands" me for leaving the inverter on because he said the refrigerator instead of going into the propane mode, was using the "ac" mode off the inverter and it drew down the batteries to an unsafe level. I didn't get why he was so concerned because won't the inverter shut off before it draws the batteries all the way down?

Anyway, my real question is, why is it not recommended to run the refrigerator off the inverter while traveling down the road? I know there have been many threads on "to use" or"not to use" propane for the refrigerator while on the road but why isn't using the inverter recommended? Since the engine is running, there shouldn't be any battery problems using the inverter while on the road, should there?

Thanks.

<span class="ev_code_BLUE">edit: sorry folks, I put in the wrong search parameters. I now have found several threads discussing this. I am at this moment reading through them to see if I can find answers to my question. However, if anybody wants to chime in on this thread, please feel free to do so!

Thanks!</span>

[03 CORVETTE]

I was told by the dealer to shut fridge off before I brought it in when I had a fridge that worked on propane or invert....if set in au and batt goes low the concern was fridge would ignite while they were working on it.....I now have all electric fridge I was told I can leave on while they work on it jim k

[scirocco22]

Thanks for the comments, Jim.

Actually, I wasn't at the dealers to have work done on the refrigerator. He just coincidentally noticed the batteries at a low level as he was working on something else and attributed it to the refrigerator drawing power from the inverter.

I've always used propane for the fridge as I'm going down the road (right or wrong, that's what I've been doing). Now that I know that the refrigerator works off the inverter, is there anything wrong with running it off the inverter as I travel down the road?

[BryanL]

Generally the fridge will run off AC if it is available assuming that that AC represents grid power.

When it is an inverter supplying the AC, the fridge is being fooled.

The fridge takes a lot of energy to keep going so running it off of storage batteries is not a good idea if you need the batteries for other things.

As for in motion, you should not run any open flame appliances when on the road. That means not using propane for the fridge or for water heaters or whatever. Since you have an alternator supplying DC power to the inverter, using that to power the fridge doesn't deplete the batteries and that allows running the fridge without an open flame.

[scirocco22]

Thanks, Bryan.

Yes, that's what I'm gathering from reading the other threads.

Definitely I should not be running the refrigerator off the inverter while dry camping. I've never done that as I know it would deplete the batteries quickly.

However, is there in fact anything "wrong" or dangerous with running the refrigerator off the inverter while moving? ...as long as I remember to turn the inverter off when coming to a stop (shutting engine off) and switching the refrigerator to propane. I have the 2000W inverter.



AND, if I do forget to switch, does the inverter in fact shut itself off before draining the batteries down to zero?

Thanks!

[cannon man]

check the shut off voltage on your inverter.12.2 volts is half dead on your batts and you should'nt go below that for good batt life. some inverters won't shut down till mabe 10.5 volts so you can see the problem. your tech did good. most do'nt know the the truth about batts. good luck. dave

[scirocco22]

Oh wow! Thanks, Dave.

Yeah, I think he told me that the voltage had drained down to 11.5 and said that was "dangerously" low.

I asked if I had done any damage to the batteries or if their life would be diminished and he said that probably not in that they're deep cycle batteries and sometimes it's good to have them dip down that far.

I'm hoping he's right and you're wrong for my sake!

Thanks again.

[RCtime]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">As for in motion, you should not run any open flame appliances when on the road. That means not using propane for the fridge or for water heaters or whatever. Since you have an alternator supplying DC power to the inverter, using that to power the fridge doesn't deplete the batteries and that allows running the fridge without an open flame.
Posts: 66 | Registered: May 24, 2007 </div></BLOCKQUOTE>

Above post by BRYANT

I have alsways run my refer off propane while on the road over 20 plus years. Whats the difference.
YES--if you pass in a tunnel that requies it to be shut off you do so,
YES- you shut it of when fueling.
Take the obvious precautions when using any open flame.
Other than than, what does using propane on a refer differ while in motion or at rest?

[John_Canfield]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by scirocco22:
--snip--However, is there in fact anything "wrong" or dangerous with running the refrigerator off the inverter while moving? ...as long as I remember to turn the inverter off when coming to a stop (shutting engine off) and switching the refrigerator to propane. I have the 2000W inverter.

AND, if I do forget to switch, does the inverter in fact shut itself off before draining the batteries down to zero?

Thanks! </div></BLOCKQUOTE>We run our fridge off the inverter while traveling about 99% of the time. I'd rather use one or two HP from the engine (driving the alternator to charge the batteries to run the inverter) than use up propane. You will not build up much if any soot in the fridge vent by not running it on propane which will reduce maintenance. I see no reason why this practice is dangerous - in fact you can probably make a much better case for not running propane while on the road (although I think this is inherently safe as well.)

Your inverter should have a low voltage alarm and/or cutoff - check the manual. It's never a good idea to deeply discharge batteries, but once in a great while should be okay.

[scirocco22]

Thanks much, John.

That's exactly the answer I was looking for.

I've been running propane for the fridge while on the road and just assumed that my refrigerator is not plugged to the inverter. Now that I know that it's plugged to the inverter, I can see no reason for not running it off the inverter while going down the road as the engine alternator is keeping the batteries charged.

However, is the refrigerator working efficiently on the inverter? I'm assuming so ...or do I need to turn refrigerator up to its highest setting and hope it can keep up? Or will it be as efficient as running it off of propane or generator?

Thanks again.

[NeilV]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by scirocco22:
Thanks much, John.

That's exactly the answer I was looking for.

I've been running propane for the fridge while on the road and just assumed that my refrigerator is not plugged to the inverter. Now that I know that it's plugged to the inverter, I can see no reason for not running it off the inverter while going down the road as the engine alternator is keeping the batteries charged.

However, is the refrigerator working efficiently on the inverter? I'm assuming so ...or do I need to turn refrigerator up to its highest setting and hope it can keep up? Or will it be as efficient as running it off of propane or generator?

Thanks again. </div></BLOCKQUOTE>

The setting is a temperature setting not a power setting so if it can't maintain 45 degrees setting it to 40 won't change anything. On my old Vectra I could run the refridgerator all day on the inverter and only had to recharge the batteries once a day. While underway I would not worry about it and enjoy the propane savings.

[John_Canfield]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by scirocco22:
--snip--However, is the refrigerator working efficiently on the inverter? I'm assuming so ...or do I need to turn refrigerator up to its highest setting and hope it can keep up? Or will it be as efficient as running it off of propane or generator?

Thanks again. </div></BLOCKQUOTE>You're quite welcome

The fridge will work a little better off propane because the propane produces greater heat than the electric heater (the ammonia refrigeration cycle operates from a heat source.) The answer to that situation is increasing the temperature setting by a number or two.

As to the absolute efficiency of inverter operation vs. propane operation, my guess is that propane operation is much more efficient - with inverter operation you are:

a- converting diesel to rotational motion
b- rotational motion is converted to 12V DC voltage via the alternator
c- DC voltage charges the batteries
d- batteries power the inverter
e- the inverter is only 85-98% efficient in converting 12V DC to 110VAC
f- inverter powers heat strips in fridge heating the ammonia
g- and finally you have a cold fridge

[Tom N]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by BryanL:
The fridge takes a lot of energy to keep going so running it off of storage batteries is not a good idea if you need the batteries for other things. </div></BLOCKQUOTE>

The heating element in my Norcold 1200 draws 225w AC. Not a large load, IMHO.

-Tom