Legend 40.5 - freezer cold plate temperature

[fero]

Hello again,
I wonder if anyone measured the temperature of the cold plate of the original freezer system once stabilized. It appears that our freezer, after doing well for number of years (setting between 4 and 5 freezing well in lowest say 5 inches), has difficulty to freeze stuff. Pointing laser temp on lower part of the cold plate it shows around -6F top part around +8F. On top of it the thermostat seems to have problem as it will not stop the compressor even when turning down to 2 (before it used to react rather quickly). For now we operate c/b on 2 1/2 to 3 h, off 1 1/2 to 2 h. Ice and snow builds up on the cold plate similarly as before needing defrost in 7 to 10 days (we are in Caribbean so 80 to 90 F ambient)
Would also be know freezer thermostat settings vs corresponding sensor temperature.
Thanks for your input.

 

[Kairos sv]

Hi, probably we have leaking gas, could be at plate or any other place. They use an “ electronic nose” to find the leaking. Good luck. I have just replaced all the unit a month ago in Le Marin .

 

[Rich Stidger]

@fero - I have the temperature data you requested, but it will take me a day or two to find it and post.

Meanwhile, my experience with the mechanical thermostats is that they are problematic and unreliable. I have replace both the refrigerator and freezer units a couple of times. The failure mode is that they become either stuck on of stuck off. I have replace the refrigerator thermostat with an electronic one and have had no issues in several years. I have a second electronic unit that I plan to use in the freezer at some point. We only use the freezer for longer cruises because it is a power hog. I run the freezer to hold 14-22 degrees F. That is enough to freeze and keep ice, but ice cream is not possible.

Here is a picture of the electronic thermostat that I am using with success.

Digital Electronic Temperature Controller Thermostat WH7016E 12V/24V/110V/220V | eBay

Electronic Components. Electronic scales. Storage Temperature: -10 ~ 60 deg C. Upper and lower limits of temperature can be set. Cable Length: Approx. Luggage & Bags. Led products. VR Glasses.

www.ebay.com

 

[smokey73]

Along the line of freezer temperature control. Where should the sensor be located for the mechanical thermostat sensor? On mine, it is inside a folded cardboard sheet between the cold plate and the side of the freezer wall (stuffed back behind the cold plate). Is that correct. @Rich Stidger I have bought an electronic thermostat but never got around to installing it. Where do you locate the sensor for the electronic thermostat? Thanks in advance.

 

[fero]

Thanks for your replies, in the meantime I have replaced the thermostat by the same mechanical one, freezer working now fine, by the way Rich I have a same digital thermostat but did not get to install one, would like to know how did you install it.
Now my problem is the fridge, it loses gas and I can’t find the leak neither with the electronic detector nor with foam (as recommended by Mr Kollmann). The unit is 30 years old, just wander if other Legend owners still have the original unit or replacements were necessary.
Thanks

 

[Rich Stidger]

@fero , Here is the freezer data that you requested. In 2009 I recharged my freezer unit, and the following notes and data is my observation during and after recharge - See the attached document. I recharged while watching the current draw per Kollmann's instruction.

My current refrigerator setup is with the electronic thermostat pictured above, and it holds the refrigerator box temperature per this note below:
08/29/2024: Refrig Electronic thermostat Set= 16, D=3, box temp= 39°

The refrigerator electronic thermostat is simply inside the refrigerator, velcro'ed to the wall near the top of the front door. I do mean to relocate it outside of the refrigerator, but that task is well down on the list since my current setup works fine.

In both my refrigerator and freezer I have a small computer fan that sucks air from the bottom of the box and blows it across to the opposite corner. This is done to help the box have an even temperature. See a picture below. Both fans are wired to the refrigerator power circuit, so I have a switch to turn off the freezer fan when I'm not running the freezer. These photos were taken in 2004 when I installed the fans. At that time I was still using a mechanical thermostat in the refrigerator.

@smokey73 - Regarding the location of the mechanical and my electronic sensor, at the bottom of the cold plate, I have a clip that is the shape of a small tube. The mechanical sensor (freezer) and my electronic sensor (refrigerator) both are inserted into that tube along with a Q-tip to hold it against the side of the tube. These sensors measure the temperature of the cold plate, not the temperature of the box. Sorry, I don't have a picture.

 

[fero]

Thanks Rich, always very good input.
How did you bring continuous 12 v inside, I have computer fans in frige and freezer but they are powered from compressor control module and are on only when compressor is running. I believe the digital thermostat needs 12 v all the time.

 

[Rich Stidger]

Thanks Rich, always very good input.
How did you bring continuous 12 v inside, I have computer fans in frige and freezer but they are powered from compressor control module and are on only when compressor is running. I believe the digital thermostat needs 12 v all the time.

You need to get the power from the 12V going into the compressor module. You should be able to find the main power into the compressor unit. Your current connection is the power to actually drive the compressor.
And, yes, the electronic thermostat needs power all of the time - but it draws very little.

 

[PNWE36]

Attached is a picture of a mechanical thermostat temperature sensor attached to a cold plate. This is typically how it is done with mechanical Tstats as Rich mentioned in post #6.This was in a chest style fridge that had a metal box in it that made up the freezer compartment/cold plate. The Alder Barbour compressor etc was mounted separately.