I am a licensed HVAC&R Tech with 11 years experience, but I do not have a lot of experience with walk-in freezers. I am new to this forum.
I have a small 6X6 that will not reach a setpoint of -15 degrees. To the best of my knowledge the unit was maintaining temp before a compressor failure 3 days ago. I was able to get an exact replacement for the compressor. After intallation, it pulled down very slowly, but there was a good deal of moisture in the box (floors and walls) and it has been very humid (around 70 percent with temps in the high 80s to low 90s). With all of the moisture, I was not too concerned that it was pulling down a bit slow, and I was at the end of the day.
I checked on the unit this morning, after 14 hours of run time, and it was hovering around 9 degrees. By this afternoon, a full 24 hours running, it never went lower than 2 degrees. I was replacing a compressor on another unit - so I did not have much time to check this one out again. I did get the following information:
-15 Ice Cream Freezer - R-404A
Box Temp: 2 degrees
Suction Pressure: 20 psig (Sat. of -15 degrees)
Ambient Temp around condensor: 95 degrees
Discharge Pressure: 330 psig (Sat. of 124 degrees)
Suction Line Temp at Compressor: 32 degrees (it is not very easy to get a temp at TXV bulb while it is running as you have to drop the fan housing to get to it)
Compressor amp draw: 9.5 (Rated RLA of 11.4)
I also did try to do a quick pump down (but it is not a pump down system - just to clarify) to check the compressor even though it is new. It took a few minutes to even approach zero, and I could not wait long enough for it to get all the way down (which it did not).
Any suggestions? I am just stuck, and I find it hard to believe that a new compressor is bad.