Parallel system compressor oil test

[rackrookie]

As I understand, in a parallel compressor rack, the compresor oil supply is being shared by all the compressors. For that reason, if I wish to test the acidity of the oil, I can take a sample from any of the compressors and regard the results as the overall state, is that right? Should I take individual samples from each compressors for more accurate results?
Also, what should be the correct level of the oil in the oil return system reservoir? I see that it has an upper and a lower sightglass.

[RobY]

Most people take one sample from each rack for oil testing. Finding the bad compressor that is causing the problem in the oil doesn't seem to be much of a problem. I've never had a customer with a rack system call and ask for more help when their oil analysis comes back screwed up.

Rob Yost
National Refrigerants

[markettech]

One sample per rack is ok. Personally, I will take the sample from the oil reservoir (if there is one) as in my mind it is the point where most of the oil originates to feed the compressors but the oil from the crank of any one compressor will most likely acheive the same result.


Generally speaking, the oil should be at some point above the lower sight glass.

[jwc64]

One sample per rack is ok. Personally, I will take the sample from the oil reservoir (if there is one) as in my mind it is the point where most of the oil originates to feed the compressors but the oil from the crank of any one compressor will most likely acheive the same result.


Generally speaking, the oil should be at some point above the lower sight glass.

Plus,
Most reservoirs have a service valve on the bottom making it an easy access
point to get your sample.

[lovecoldair]

i agree