compressor failures -3 in 3 years

I have a 8x10 walk in cooler the compressor/ condensor is on the roof in a “doghouse” The compressor continues to fail this will be my 3rd in 3 years. The refrigeration company just wants to replace compressor but my thought is there is something in the system causing them to fail.

The unit is 17 years old and 6 years ago I had it relocated from inside mounted on top of walkin to the roof to remove the heat and noise

Any thoughts or experiences?

I’d have a few other companies look at it to make sure it’s not a design or other component issue that’s causing the problem. I assume the doghouse is adequately ventilated. Sometimes a fan can be installed in the doghouse to remove heat build up. Did they run the proper gauge electric wire to the roof?

Need a bit more on how the compressor is failing. Is it seizing, or is it electrically burning up. The reason for this is that with the relocation to the dog house to the roof (a good move) you need to have the suction line redesigned properly (oil trap … google refrigeration oil trap) to get the oil return to the compressor, this would result in a seize of the compressor if not done. If it is a true burn up, then there is residual acid in the system, this may not seize. Put a new compressor in, and not treat the acid problem and the new compressor will be dead in a year from residual acid in the system.

Acid remediation would be a suction line filter dryer and a liquid line filter dryer. (Some techs prefer just an oversized liquid line filter dryer) but it needs to be a filter dryer that can deal with acid, like an Emerson EK series. Good practice after a burn up, is new oversized filter dryers. Then back in a week to do an oil change and test old oil, (hard and expensive on hermetic unit as you must break the system open and remove compressor to drain oil), replace liquid line filter dryer, remove suction line filter dryer, and fill with new refrigerant. I would come back in a year and do it again, at least test oil, change liquid line filter dryer and new refrigerant. If oil tests bad, then another oil change. The acid lives in the oil, and the oil circulates in a refrigeration system. Burnouts are a real pain to get the system clear of acid. But it is necessary to get back to the original life time. There are some “treatments” (chemicals to add to neutralize the acid), but not widely used.

Then there is the possibility that the refrigerant was changed when the dog house was installed. Was there a change from R-22 with mineral oil to a “new” refrigerant like R-404A? If such a change was made, there needed to be an oil change to Polyol Ester Oil (POE).

Lots of stuff going on. At least I gave you a few questions to ask your tech. If he does not converse well with you in these areas, it’s time to get another service company on your equipment.

Just had a 2nd company come out . The first company is the one that relocated the unit in the first place.

Findings from 2nd company

  1. No Heater
  2. No headmaster
  3. New compressor already has bubbles in sight glass indicating a leak in a line ( I asked first company if that was a possibility)
  4. I went up on the roof with the 2nd company to find loose screws left all around unit on brand new rubber roof.

I asked the first company(yes they are a legitimate company - probably 15 employees) Is there anything else we can do or need to prevent this from happening or create a better environment for the compressor and was told no on a number of occasions.

2nd company recommends replacing the entire unit with exception of box

Thanks for reply’s guys

Sometimes in the long run, total replacement is cheaper than the labor cost trying to remediate all your problems. Given that the entire system is 17 years old… with an expected lifetime of 20 t0 25 years or so… you are not that far out of its expected total life. Storing vinegar products in the walk in will also effect the evaporator lifetime. If the system is R-22 the cost of that refrigerant is very high per pound. New system should equal new refrigerant with lower cost per lb and future availability.

For example: As per the US Environmental Protection Agency, R22 refrigerant will become illegal to produce or import into the United States on January 1, 2020. I think you can still use stock on hand to service clients refrigeration systems.

This leaves owners of R22 filled refrigeration systems and air conditioners 3 choices:
[]Do nothing until your system needs an expensive repair and then replace.
]Retrofit (or convert) your old R22 equipment to use an existing approved refrigerant (say 404a for refrigeration systems and R-407C for air conditioning) and deal with the change of lubrication oil requirement. Typically mineral oil to Polyol Ester Oil (POE)

[*]Replace your system proactively.