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Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: Tom Lang on June 09, 2014, 08:05:27 pm

Title: refrigerator Amp-hours question
Post by: Tom Lang on June 09, 2014, 08:05:27 pm
Since my Domestic is non operational at the moment, I cannot go out and measure how much DC current it uses when running on propane.

I want to know that, along with the Amp-hours used per day by a big, 20+ cu-ft residential refrigerator, by a small, around 10 cu-ft residential, and by a similarly sizes as/DC marine compressor driven refrigerator.

Thanks, Tom
Title: Re: refrigerator Amp-hours question
Post by: Barry & Cindy on June 09, 2014, 09:22:41 pm
Do our 24" x 58" 10 cu ft Whirlpool fridge spread sheet calculations help?  We put them together with our Kill-O-Watt meter.

Does not matter anymore to us, how much electricity it uses, because we now have 2 degree freezer, 40 degree fridge temps, a little larger inside than our propane and pretty hard ice cream.  And we had no new problems boondocking for 10 days about a year ago in Quartzsite, with the electric fridge.

We decided to replace with electric before our propane broke.
Title: Re: refrigerator Amp-hours question
Post by: rsihnhold on June 09, 2014, 09:24:29 pm
My 7.5 cu foot Norcold 982 draws about 350 watts on 120vac and is a massive battery killer with my 2x250ah batteries since I have it wired into my inverter currently.  On DC, I seem to remember it drawing about 3 amps at 12vdc for around 36 watts with propane, it might be less than that on DC though.

From what I have noticed myself, it seems to run about twice as long as it is off.  In every hour, it is running about 40 minutes and not active around 20 minutes which is not a good combination for efficiency and is a much better measurement for how much battery power a unit consumes.
Title: Re: refrigerator Amp-hours question
Post by: Tom Lang on June 10, 2014, 12:57:16 am
Seemed to me the tms2020 was seeing an additional 1A when the Domestic 1492 was on, increasing to 2A when the propane burner was on. Does this sound right? If so, a residential refrigerator might not use that much more power than an RV refrigerator. I would like someone with a still working Domestic to look into this.

Unfortunately, rv refrigerator manufacturers are not freely giving out power use information.
Title: Re: refrigerator Amp-hours question
Post by: Lon and Cheryl on June 10, 2014, 03:48:31 am
My 20cu ft Bosch says it uses 5.25 amps.
Title: Re: refrigerator Amp-hours question
Post by: Dave M (RIP) on June 10, 2014, 05:34:42 am
Since I am not too bright, I just enjoy the 2f ice cream and 34f refrig, keeps everything very happy. The 24 cf Samsung has seperate adjustable thermostats.
Read somwhere about the AC draw, but that has been long forgotten. Having the 4th 8D Gel and my running the generator in the AM for breakfast & recharge for about 2-3 hours a day works for me.  That gives me 21-22 hours a day of quiet.  ;D
Title: Re: refrigerator Amp-hours question
Post by: wolfe10 on June 10, 2014, 06:59:54 am
And, running on propane, your absorption refrigerator takes VERY little 12 VDC-- Just enough to power the propane solenoid and the PC board and igniter. Probably averages less than 1 amp.
Title: Re: refrigerator Amp-hours question
Post by: wa_desert_rat on June 10, 2014, 10:18:26 am
I know you asked about DC power draw when on propane but I thought I'd add this as corroboration of rsighnold's report.

When I checked the AC power draw of our Dometic absorption-type (RV) refrigerator every time I looked at the kill-a-watt it was drawing 3-amps of 120vac! That translates to about 30-amps of 12vdc if it were hooked up to the inverter and killed any idea I might have had about running the Dometic on the battery bank/inverter even with 620-watts of solar! It probably turned off at some point but, if it did, I didn't catch it!

Just waiting on Propman's residential installation report before I buy and convert ours!

Craig