Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×


Reply
 
Thread Tools Display Modes
Old 07-21-2019, 08:54 PM   #1
Member
 
Join Date: Jan 2018
Posts: 44
Isata 5 36DS - Can the fridge be made to run thru inverter?

I have the Dometic fridge (non-residential) in our RV. Currently, it isn't wired thru the inverter. However, I recently replaced the AGM batteries with 660AH of lithium batteries. I also have 500W of roof mounted solar panels and 460W of portable panels. I'd like to have the fridge run off the inverter while we're boon docking. It came with a 2800W inverter. Looking at our usual electrical loads, it seems like there's plenty of capacity in the inverter. Is this an easy project? Thanks in advance!
__________________
2019 Dynamax Isata 5 36 DS 4X4
2010 Jeep Wrangler
RedSteelManUSA is offline   Reply With Quote
Old 07-22-2019, 06:40 AM   #2
Senior Member
 
Join Date: May 2014
Location: IL
Posts: 1,295
Hi,

I have 600 watts of solar and a 2000 watt pure sine wave inverter. I can, and have briefly as an experiment, operated my Dometic refer on 120 while boondocking in Quartzsite. Never did it for a full day to get better informed about total energy consumption. But what I recall seeing on my Trimetric monitor in the short term was a pretty high current demand.

It works, of course. But as a rule I don't do it because the battery drain is pretty high, and the way I see it propane is just not that expensive. My operational theory starts with "why cycle the batteries any more deeply than necessary?"

FWIW.

Rich Phillips
__________________
Rich Phillips
2019 K-2500 Duramax Crew Cab
2014 Silverback 33RL
richp is offline   Reply With Quote
Old 07-22-2019, 08:36 AM   #3
Senior Member
 
Join Date: Oct 2017
Posts: 850
It would be nice to select it to run on 12 volts inverted while driving, like the 3-ways were.
Magnatudes is offline   Reply With Quote
Old 07-22-2019, 08:51 AM   #4
Commercial Member
 
Join Date: Nov 2007
Location: Bristol, IN
Posts: 18,878
I sort of thought, though I'd have to check, that pretty much all the outlets on the Isata 5 were inverted. We run an Inverter/Charger as opposed to a standard converter. Have you tried setting it for "electric only" yet to test? I can't remember how the "auto" works. If that is LP only or auto...or if you can select electric only.
__________________
If "Search this Forum" does not yield answers, please post questions as a "New Thread" (instead of asking privately) so others can benefit from the answers.

Subscribe for "How To" videos and updates https://www.youtube.com/c/DynamaxRVs/

Sales-Service-Parts https://dynamaxcorp.com/contact-us
bclemens is offline   Reply With Quote
Old 07-22-2019, 09:02 AM   #5
Senior Member
 
Join Date: Jan 2015
Location: Englewood FL
Posts: 2,797
An RV reefer draws about 600 watts on AC. That would be at least 50 amps of 12 volt! It also runs on a pretty high duty factor.
__________________

2015 335DS
ScottBrownstein is offline   Reply With Quote
Old 07-22-2019, 09:06 AM   #6
Commercial Member
 
Join Date: Nov 2007
Location: Bristol, IN
Posts: 18,878
But it also has a 110V connection when on shore power.
__________________
If "Search this Forum" does not yield answers, please post questions as a "New Thread" (instead of asking privately) so others can benefit from the answers.

Subscribe for "How To" videos and updates https://www.youtube.com/c/DynamaxRVs/

Sales-Service-Parts https://dynamaxcorp.com/contact-us
bclemens is offline   Reply With Quote
Old 07-22-2019, 09:13 AM   #7
Senior Member
 
caseymyers's Avatar
 
Join Date: Jan 2018
Posts: 1,564
I think the problem with the 12 volt fridge on AC is you are just heating the ammonia with a large electric element not unlike on a toaster or hair dryer. It will work but you are really burning up lots of AMPS compared to a residential fridge. Don't know the AMP draw but you could easily measure it and I think it's constant, always on. I would guess in this application with all the extra solar and batteries a residential fridge would be more efficient. The advantage of the RV fridge is of course it'll run on propane.
__________________
Old Navy Chief
2019 Isata 5 36' DS 4x4
2015 Jeep Rubicon Toad
Days camped 2021 = 25
caseymyers is offline   Reply With Quote
Old 07-22-2019, 09:24 AM   #8
Member
 
Join Date: Jan 2018
Posts: 44
Thanks all for the input! The way it operates (pretty sure) is it uses 12v for the control boards and 110v for the compressor when on electric/auto. So, when we're on shore power, it runs from that. I saw about 8 amps draw from a quick look last week via the multiplex while I was on 30a service. It switches to LP with no shore power. Would the generator provide power if it was running...just wondering? I thought I'd run a quick and easy experiment and plug the 110 power cord for the fridge into one of inverted outlets and double check the draw/load. That's a lot less than the 50a mentioned previously. I'll keep you guys posted when I get some real world numbers. BTW, is there a single line diagram available for the electric on the 36DS? Thanks again!
__________________
2019 Dynamax Isata 5 36 DS 4X4
2010 Jeep Wrangler
RedSteelManUSA is offline   Reply With Quote
Old 07-22-2019, 09:30 AM   #9
Senior Member
 
Join Date: Jan 2015
Location: Englewood FL
Posts: 2,797
Quote:
Originally Posted by RedSteelManUSA View Post
Thanks all for the input! The way it operates (pretty sure) is it uses 12v for the control boards and 110v for the compressor when on electric/auto. So, when we're on shore power, it runs from that. I saw about 8 amps draw from a quick look last week via the multiplex while I was on 30a service. It switches to LP with no shore power. Would the generator provide power if it was running...just wondering? I thought I'd run a quick and easy experiment and plug the 110 power cord for the fridge into one of inverted outlets and double check the draw/load. That's a lot less than the 50a mentioned previously. I'll keep you guys posted when I get some real world numbers. BTW, is there a single line diagram available for the electric on the 36DS? Thanks again!
If it drew 8 amps when on 110 volt shore power it will draw 80 amps when on 12 volts with an inverter. RV adsorption reefers do not use a compressor when running on AC but rather a great, big, 600 watt resistive heating element.
__________________

2015 335DS
ScottBrownstein is offline   Reply With Quote
Old 07-22-2019, 10:20 AM   #10
Senior Member
 
Join Date: May 2014
Location: IL
Posts: 1,295
Hi,

These 50-80 DC amp numbers are the kind of load I vaguely recall when I did my little experiments.

It wouldn't be a constant drawdown on the batteries, of course. But even with the panels and storage the OP mentioned, I'd bet this would not be a long term operational option.

FWIW.

Rich Phillips
__________________
Rich Phillips
2019 K-2500 Duramax Crew Cab
2014 Silverback 33RL
richp is offline   Reply With Quote
Old 07-22-2019, 10:29 AM   #11
Junior Member
 
Join Date: Jul 2019
Posts: 5
My new trailer has a domestic fridge only. I have a 1000 watt inverter and 3 12 volt batteries. As a test I disconnected from shore power and ran the fridge for 9 hours off of the inverter. At the end my batteries were still over 12 volts
Busdriverbob is offline   Reply With Quote
Old 07-22-2019, 01:09 PM   #12
Senior Member
 
Join Date: Jan 2018
Location: Raleigh, NC
Posts: 9,413
Easy to measure

Easy to measure. Just put this device
https://www.amazon.com/Bosch-SP0F000...8-75d51cd19f4a

in line with the 12v connection to the inverter.
__________________
Larry
"Everybody's RV is not like your RV."
"Always take pictures with the button on the right."
"Always bypass the water heater before opening the low-point drains."
Sticks and Bricks: Raleigh, NC
2008 Cherokee 38P: at Ivor, VA permanently
Larry-NC is offline   Reply With Quote
Old 07-22-2019, 01:12 PM   #13
Senior Member
 
Join Date: Jan 2015
Location: Englewood FL
Posts: 2,797
Quote:
Originally Posted by Larry-NC View Post
Easy to measure. Just put this device
https://www.amazon.com/Bosch-SP0F000...8-75d51cd19f4a

in line with the 12v connection to the inverter.
Save your money...get one of these...https://www.amazon.com/Bogart-Engine...omotive&sr=1-1
__________________

2015 335DS
ScottBrownstein is offline   Reply With Quote
Old 07-22-2019, 01:32 PM   #14
Senior Member
 
Join Date: Jan 2018
Location: Raleigh, NC
Posts: 9,413
Huh?

Quote:
Originally Posted by ScottBrownstein View Post
Save your money...get one of these...https://www.amazon.com/Bogart-Engine...omotive&sr=1-1
Huh?

I was pointing to a $13.94 product and you thought a $152 product was cheaper?
__________________
Larry
"Everybody's RV is not like your RV."
"Always take pictures with the button on the right."
"Always bypass the water heater before opening the low-point drains."
Sticks and Bricks: Raleigh, NC
2008 Cherokee 38P: at Ivor, VA permanently
Larry-NC is offline   Reply With Quote
Old 07-22-2019, 01:33 PM   #15
Senior Member
 
Join Date: May 2014
Location: IL
Posts: 1,295
Hi,


Dittos on getting the Trimetric equipment, or at least its real equivalent. If you are serious about such things, that level of sophistication is absolutely vital in knowing what is really going on with your system.


Rich
__________________
Rich Phillips
2019 K-2500 Duramax Crew Cab
2014 Silverback 33RL
richp is offline   Reply With Quote
Old 07-22-2019, 01:35 PM   #16
Senior Member
 
Join Date: Jan 2015
Location: Englewood FL
Posts: 2,797
Quote:
Originally Posted by Larry-NC View Post
Huh?

I was pointing to a $13.94 product and you thought a $152 product was cheaper?
Nope, the $152 product is far more useful...forever and really should be standard equipment on any boondocking RV anyway.

I am amazed that they still make d'arsonval meter movements. Dating myself.
__________________

2015 335DS
ScottBrownstein is offline   Reply With Quote
Old 07-22-2019, 01:41 PM   #17
Member
 
Join Date: Jan 2018
Posts: 44
My lithium batteries allow me to connect via bluetooth and monitor draw on them. It should be pretty accurate and reliable.
__________________
2019 Dynamax Isata 5 36 DS 4X4
2010 Jeep Wrangler
RedSteelManUSA is offline   Reply With Quote
Old 07-22-2019, 02:04 PM   #18
Senior Member
 
rlh1957's Avatar
 
Join Date: May 2017
Location: Southeast
Posts: 1,047
LP is cheap and usually performs better at cooling an RV fridge than when on electric. Running AC from an Inverter will use battery down and you must watch for the draw getting down to 50% on your batteries. Inverters themselves draw a bit just to operate when not even supplying anything.
The inverters do work.
__________________
2018 Forest River Rockwood Roo
24WS

2019 Ford SD F-350 SRW Lariat
Tow & Gooseneck Prep
FX4 Off Road (4X4)
rlh1957 is offline   Reply With Quote
Old 07-22-2019, 02:22 PM   #19
Senior Member
 
Pod2Vibe's Avatar
 
Join Date: Jul 2014
Location: Foresthill, CA
Posts: 329
Quote:
Originally Posted by rlh1957 View Post
LP is cheap and usually performs better at cooling an RV fridge than when on electric. Running AC from an Inverter will use battery down and you must watch for the draw getting down to 50% on your batteries. Inverters themselves draw a bit just to operate when not even supplying anything.
The inverters do work.
OP has Lithium so the 50% rule does not come into play.
__________________
Pod2Vibe
Magnetic 2019 Isata 5 30FW 4X4 (arrived 2/15/19)
TOAD: 2014 Fiat 500 Abarth

2015 Solera MBS 24R - Hellwig/Sumo Equipped, Sold
(Sold the Vibe TT, as well)
Pod2Vibe is offline   Reply With Quote
Old 07-22-2019, 03:05 PM   #20
Senior Member
 
Join Date: May 2014
Location: IL
Posts: 1,295
Hi,

Well lithiums make a difference for sure, but...

He has 660 amp hours in the battery bank. Ignore inverter loss for a moment. If the refer used a mid-range number of 65 amps per hour at (guessing) a 50 percent use cycle, then theoretically there are 20 hours of use available. Actual data on the amount of time the heating element is powered would be critical here -- something that would itself vary by season and ambient temperatures.

The remainder of the equation involves how many other appliances will run off the inverted 120 also, and how many amps his very significant panel array can provide.

It seems doable, but as someone noted above, propane is evidently more effective than resistance elements in these units.

Very interested in some actual performance data over time.

FWIW.

Rich Phillips
__________________
Rich Phillips
2019 K-2500 Duramax Crew Cab
2014 Silverback 33RL
richp is offline   Reply With Quote
Reply

Tags
fridge, inverter

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Featured Campgrounds

Reviews provided by

Disclaimer:

This website is not affiliated with or endorsed by Forest River, Inc. or any of its affiliates. This is an independent, unofficial site.



All times are GMT -5. The time now is 10:00 PM.