They are model N8WB's. We have had seal leakage once, but our big issue has been a complete seizing of one of the compressors due to some sort of sludge that bound the pistons to sleeves. Twice now we have completely rebuilt this compressor due to this mystery substance. The immediate thought was that it was due to moisture in the system but tests don't necessarily validate that concept.

We cut apart the oil separator (Henry COS-140) that serves this particular compressor and found this insulation-like material that was badly disintegrated. We believe this is the substance that made it's way into the compressor and caused the failure. We've replaced the oil separator.

We have been going at this issue for three years now without any definitive resolution. The compressor in question has just recently been shut down but ran for the last 9 months without issue. We will soon take the head off to see what it looks like. Hopefully the new oil separator and the two rebuilds have solved the issue. However, there are new refrigeration techs that are pointing at the Mycold AB68 as the cause. I am just a facility operator, not a refrigeration tech, so I am trying to learn how that may, or may not, be a valid possibility.