Dometic RM8551 insuffucent cooling - Page 11 - Escape Trailer Owners Community

Go Back   Escape Trailer Owners Community > Escape Tech > Escape Systems | Water, Waste, Charging & Propane
Click Here to Login
Reply
 
Thread Tools Display Modes
 
Old 06-30-2015, 09:04 AM   #101
Senior Member
 
Zardoz's Avatar
 
Join Date: Feb 2013
Location: Marana, Arizona
Trailer: 2017 5.0 TA
Posts: 1,050
Quote:
Originally Posted by Patandlinda View Post
Rich makes sense . The switch is wired into the control box ? Do I just cut that wire and forget about it . Just wire that fan on the back like I did my inside fan ? It is that simple ? Pat
I'll try to be real clear, so bear with me since I too struggle with anything electrical: 1.) I cut the wires leading out from the fan leaving enough wire(s) from the fan to spice-in about 3 to 4 feet onto both the hot and cold fan wires (I then discarded all remaining stock fan wiring and the thermal switch); 2.) I then ran the new, longer hot and cold fan wires to another power nearby 12V power source with the switch in-line on the hot side; 3.) I located the switch where there is room on the control panel and taped the wires running up over the fan down to the top of the fridge. NOTE, I did NOT wire anything "into" the control panel, I just located the switch there where there was room "on" the panel.
__________________

Zardoz is offline   Reply With Quote
Old 06-30-2015, 10:37 AM   #102
Senior Member
 
Patandlinda's Avatar
 
Join Date: Sep 2013
Location: Ventura County, California
Trailer: 2013 19 Escape
Posts: 4,008
Quote:
Originally Posted by Kountrykamper View Post
If you just jump across the 2 wires on the thermo switch the fans will run if you have 12 volt power to the fridge or take the wires off the switch and touch them together. All the thermo switch does is close the contacts inside when it get to 150 degrees and completes the circuit to allow the fans to run. The new switch is just installed across the same 2 terminals of the thermo switch and bypasses the thermo switch and makes the fan run when turned on. Leave to original 2 wires on the switch and add 2 wires (one more to each terminal) that you run to the new switch. If you touch the ends of these new wires together it will jump the switch and will be the same as turning on the new switch and your fans will run.

Or you can take the thermo switch out of the circuit like Rich did and rewire the fans supplying them their own 12 volt power supply but I think the easiest way is to just jump the thermo switch with a manual switch.

My switch is located in the upper cabinet above the fridge.

Hope this helps
Got your message . My power is going off any minute if you don't hear from me . Went to Home Depot last night and got some items to insulate box . Pat
__________________

Patandlinda is offline   Reply With Quote
Old 06-30-2015, 10:41 AM   #103
Senior Member
 
Patandlinda's Avatar
 
Join Date: Sep 2013
Location: Ventura County, California
Trailer: 2013 19 Escape
Posts: 4,008
Quote:
Originally Posted by Zardoz View Post
I'll try to be real clear, so bear with me since I too struggle with anything electrical: 1.) I cut the wires leading out from the fan leaving enough wire(s) from the fan to spice-in about 3 to 4 feet onto both the hot and cold fan wires (I then discarded all remaining stock fan wiring and the thermal switch); 2.) I then ran the new, longer hot and cold fan wires to another power nearby 12V power source with the switch in-line on the hot side; 3.) I located the switch where there is room on the control panel and taped the wires running up over the fan down to the top of the fridge. NOTE, I did NOT wire anything "into" the control panel, I just located the switch there where there was room "on" the panel.
Rich the red wire from that fan goes into I believe it is a control box . It is Ok to cut that wire ? Understand and clean installation for your new switch on the front control panel . Think I want to do the same . Power is going off here soon if you don't hear from me . Pat
Patandlinda is offline   Reply With Quote
Old 06-30-2015, 10:46 AM   #104
Senior Member
 
Zardoz's Avatar
 
Join Date: Feb 2013
Location: Marana, Arizona
Trailer: 2017 5.0 TA
Posts: 1,050
Pat, I cut all of the wires that went various places to the fridge (including what could be called a "control box") with no negative consequences. I would think it would be fine for you too. But l too really held my breath and crossed my fingers. In the end it all worked out.
Zardoz is offline   Reply With Quote
Old 06-30-2015, 11:01 AM   #105
Senior Member
 
DonF's Avatar
 
Join Date: Jul 2013
Location: Corinth, Mississippi
Trailer: 2014 19' Escape
Posts: 153
Another view on RM 8551 performance

I've followed the various refrigerator performance threads with interest. But, before I started to solve a potential problem, I thought I would see what kind of problem I really had. With that objective in mind, I monitored the daily performance of our RM8551 on our recently completed trip through the Southeast and here's what I found. No modifications or additions had been made to the refrigerator.
Procedure
For recording the refrigerator temperatures, I used an AcuRite 00986Wireless Digital Thermometer with one sensor under the freezer shelf and one on the bottom refrigerator shelf. The outside temperature data came from an AcuRite 01033W Weather Forecaster with the outside sensor hanging under the propane tank cover.
The refrigerator was operated on both 110V or propane during the trip. No difference in performance was noted.
When towing, the unit was always on propane and the AcuRite monitor was in our Pilot so the refrigerator temperatures could be monitored. Refrigerator worked as well during towing as when parked.
The default cooling setting was, and is, 4.
The refrigerator was operated on setting 5 for one three day period and another four day period.
In both cases, average freezer temperature decreased by one degree, average refrigerator temperature increased by one degree.
The default location for the temperature sensor was, and is, on the cooling fin. I moved the temperature sensor from the cooling fin to the wall for a five day period.
During that period, measured data showed the average freezer temperature increased by two degrees, while the average refrigerator temperature decreased by two degrees.
Results
The chart illustrates the performance experienced during this trip.
RM8551.JPG

Observations
Quote from the Dometic Manual - "For physical reasons, an absorption system responds slowly to changes made by the thermostat controller, by loss of cooling energy through opening the door,or during storing food." We certainly found that to be true - adding any appreciable amount of room temperature items of "warm" leftovers caused a spike in the measured air temperature that sometimes took hours to recover. The same would happen if the door was open long enough for the alarm to go off.

Obviously, the AcuRite readings are air temperature readings and are do not represent the actual temperature of the items in the refrigerator. I do not know the relationship between changes in air temperature and the actual temperature of the food in the refrigerator. Per the AcuRite literature, the temperature accuracy is +/- 2 F and the readings are not "instantaneous" AcuRite says the temperatures are updated every 16 seconds. From my observations, the time between updates was as high as 2 minutes. When I removed the sensors from the refrigerator at the end of our trip, it took 45 minutes before they indicated the correct ambient temperature.

The vent fan mounted on the bottom left corner on the rear of the refrigerator never came on.
According to an email I received from Dometic , "theearliest the fan would kick on is 105 degrees Fahrenheit." I could not measure the temperature at the exact location of the controlling thermostat but measured temperature in the general area was over 120 degrees at a time when the air temperature was in the upper 90's and the outside refrigerator area was in full sun; the fan should have been running. Our Escape is currently at our local RV shop to fix whatever the problem is.

Conclusion
We are OK with the how our refrigerator performed during this trip and was surprised how well it did at temperatures above ninety degrees. We never had to discard any food, we never had any milk go bad, and cold beverages were always cold when consumed. In theory, fixing the rear vent fan will improve performance over what was measured during this trial.

Of course I would like to see a tighter range in the temperature swings during a day but managing how the refrigerator is used was the key factor in keeping our cold stuff cold and frozen stuff frozen. At least for now, we'll continue to work on "changing our refrigerator habits" (Cheryl calls it "common sense"). In our case, I found I didn't really have a problem worth solving and am not planning any physical changes to the refrigerator or it's installation.




__________________
Don & Cheryl
http://www.corinthrose.com/Galleries/Escape-Travels
DonF is offline   Reply With Quote
Old 06-30-2015, 12:12 PM   #106
Senior Member
 
Join Date: Nov 2012
Location: Little Rock, Arkansas
Trailer: 2014 Escape 19' and 2016 GMC Yukon SLT SUV.
Posts: 242
Send a message via AIM to Tonny LR
Don,
I appreciated you sharing this well documented study.

Tonny
Tonny LR is offline   Reply With Quote
Old 06-30-2015, 01:58 PM   #107
Senior Member
 
Zardoz's Avatar
 
Join Date: Feb 2013
Location: Marana, Arizona
Trailer: 2017 5.0 TA
Posts: 1,050
This is good data, Don; thanks for sharing. Much better to have numbers to look at!
Zardoz is offline   Reply With Quote
Old 06-30-2015, 02:05 PM   #108
Senior Member
 
rbryan4's Avatar
 
Join Date: Jun 2014
Location: San Antonio, Texas
Trailer: 2015 19 "Past Tents", 2015 F150 Ecoboost
Posts: 7,598
Quote:
Originally Posted by DonF View Post
Of course I would like to see a tighter range in the temperature swings during a day but managing how the refrigerator is used was the key factor in keeping our cold stuff cold and frozen stuff frozen. At least for now, we'll continue to work on "changing our refrigerator habits" (Cheryl calls it "common sense").
That's true Don. You have to learn to use an RV fridge differently than the one at home, to be sure. We've found that the trusty Ice Chest for drinks is our go to place, which means we only have to open the fridge once or twice during meal prep. I'll bet our fridge only gets opened 4 times a day or so, and then for only a brief few seconds.
__________________
"You can't buy happiness, but you can buy an RV. And that is pretty close."
rbryan4 is offline   Reply With Quote
Old 06-30-2015, 02:17 PM   #109
Senior Member
 
Join Date: Aug 2012
Location: N/A, Indiana
Trailer: Escape
Posts: 931
"Reace said to move that switch at back closer to chimney"
Can the thermal switch on the condenser be moved without removing the frig ?
__________________
"Never argue with an idiot. They only bring you down to their level and beat you with experience." George Carlin
Jubal is offline   Reply With Quote
Old 06-30-2015, 05:56 PM   #110
Senior Member
 
Patandlinda's Avatar
 
Join Date: Sep 2013
Location: Ventura County, California
Trailer: 2013 19 Escape
Posts: 4,008
Quote:
Originally Posted by rbryan4 View Post
That's true Don. You have to learn to use an RV fridge differently than the one at home, to be sure. We've found that the trusty Ice Chest for drinks is our go to place, which means we only have to open the fridge once or twice during meal prep. I'll bet our fridge only gets opened 4 times a day or so, and then for only a brief few seconds.
Robert been rving for 30 years . Have had this , is number 3 Dometic . This frig doesn't quite work as well as previous frigs . We know all the little tricks to help this out . None of this works for us . We have both mechanical and digital to record temps . Have carried a ice chest with every rv . This frig takes a long time , for us to recover , according to Domectic cavity where frig is mounted should have installtion and smaller clearances which it doesn't have . That is one of the reasons for pulling frig out to correct these items and anything else to improve the performance . For this frig to be parked in shade , outside temps to be around 75 degrees , fan Dometic installed never to come on , it was very hot back there , no matter what outside temps previous outing much hotter outside , fan never came on . Cost to replace this frig over 1000. Which is 10 -11 % of the whole cost of trailer . Don't expect much , know how these frigs work but you open your door and it takes to later at

night to recover . I have lots of things to fill my time I really don't relish taking apart my trailer for work which is not a fun mod . I'd rather do fun mods or go camping . Really mostly drink water , only open frig for breakfast and dinner . Glad you have no problems . Only want maybe a few more lower degrees until it can catch up . Pat
__________________

Patandlinda is offline   Reply With Quote
Reply

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






» Virginia Campgrounds

Reviews provided by



All times are GMT -5. The time now is 02:52 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Copyright 2012 Social Knowledge, LLC All Rights Reserved.