What is wrong with my isotherm compact classic 2013?

[Eric Jan]

Hi everyone,

A couple months ago I installed a Danfoss BD50 based Isotherm Compact Classic 2013 fridge system. It has semi wonky behavior from the start.

And I suspect something is not right as the compressor seems to run A LOT. Eating up say 75-100 amp’s a day?

Biggest potential signs:

• The evaporator only freezes over 25-30% the rest no frost (it never got more)
• It runs pretty much continuously during the day (5-9 hours in a row). Then on and off for hours at night.
• Currently it does seem to hold its temperature low at between 1.0 – 2.5 degrees Celsius with the thermostat at appr. 25% (just on).
• The compressor and evaporator plate did NOT have matching numbers, but supplier confirmed this was no problem.

Situation:

• Re-installed & isolated the fridge that is appr. 250+ liters (Isotherm 2013 should be good for up to 400) with PIR between 6cm – 27cm (bottom 27cm, 1 side 6-8cm, the other sides between 15-25cm).
• When room temp. is around 20-25 degrees, the fridge runs constantly but keeps it (still) at <2.5 degrees Celsius.
• Plenty of voltage & power, holding steady
• Cooling fan runs nicely and has access to fresh cold air
• I had some challenges figuring out the temp sensor placement (that is the wonky behavior referral, it basically turned on and off for couple minutes and slowly I had to turn the thermostat to work harder. After moving the thermostat a couple places it seems better)
• The evaporator plate was bend in 2 locations that are allowed and with the supplied 'template bending woody things'
• There are no tight tight bends in the lines

So the questions:

• Is this okay behavior? Or is there something clearly wrong?
• Can I just switch out the compressor to try? (hate to break the fridge to get the evaporator plate out)
• What do you recommend me?

I have been ping-ponging with the supplier, no real progress just yet (they are very willing to figure it out)

[tkeithlu]

It sounds like one of two problems IMHO. Either the insulation in the fridge has a major leak, letting cold air out, or the refrigerant is low, such that little cooling is transferred. From your description, it sounds like the compressor is running just fine.

Check on the first by searching the gaskets, corners, tubing entrance, and the like for escaping cold air. Look for frost in the wrong place and surfaces that are cold to the touch on the outside. Everything outside the gasket should be at room temperature. Caulk like crazy, and if the whole box is cool to the touch, add insulation.

For the second possibility you need a pressure test. That requires equipment, such as this:

https://www.amazon.com/XtremepowerUS...xpY2s9dHJ1ZQ==

or it may be simpler to have an AC tech pay you a visit.

That's everything that comes to mind this peaceful Saturday morning. Diagnosis beyond that I think will require expert help on the site - remember that refrigerators are air conditioners with very low thermostats, so the expertise is out there.

Good luck with it.

[Eric Jan]

Thank you @tkeithlu,

And just to keep the forum up to date.

I had a fridge mechanic come by and he filled it with a good chunk of additional gas.

Since the whole plate is able to freeze over.

I currently have the following behavior and that is that the fridge turns on for say 5 minutes and is then off for 10 minutes. then on again for 5, etc.

the time differs a bit on situation, but it seems to be on 33% of the time.

No idea if that is good, but the temp in the fridge is rock stable and cold at 4.0-4.5 degrees celsius (with thermostat set on 'just on').

If anyone believes this behavior is incorrect, let me know

[Searles]

Had lot of experience with these units here in oz under the waeco name,one of the first instulations is now 30 yrs old still runs fine, to date replaced two thermostats ,one controler box ,with the inside temperature of the boat about 26 c it runs about 1/4 of the time holding about 4c ,gas’s check every two yrs ,the main trick is to keep in fridge as full as practical,with bottled water etc plus pay attention to the seals . Have also used the 50 comp and rage blower freezer unit verry successfuly with daily in fridge boxes ,over all excellent units .⛵️⚓️