"Peter H" wrote in message
...
I'm hoping someone in this group will take the time to answer this for me.

I'm in the middle of a course on HVAC in high-rises. The instructor has
stated that the oil in the HVAC system should be checked regularly for
quality and impurities.

Yes, you can take oil samples and send them in to labs. These tests can,
depending on what you want tested, show if the compressor is running hot or
if there is some flooding, moisture, acid and other issues.

She says that if refrigerant is detected in the oil
then there is a problem.

I thhink she's talking about liquid here. You will always have some
refrigerant in the oil but saturated with refrigerant is a big problem. This
can result from migration or flood back.

I was always thought that there is oil in the
system with the refrigerant and that this oil lubricated the compressor
etc.and one would expect to find refrigerant mixed in with it. I thought
that this was why you are always told to let a newly delivered fridge
stand
for an hour or two before turning it on, to let the oil drain back down
into
the compressor.

I was told to let it settle down because of debris in the crankcase being
disturbed coud plug the cap tube. It doesn't matter for me because I always
heat the compressor up before plugging ours in.

I'm surprised she didn't mention a MegOhm reading being taken and logged as
well.

The reason she is talking about these topics is with typical large highrises
the compressors are very expensive. Parts can be limited if its an older or
specialty brand. It is normal to test centrifugals and screw compressors. I
remember before oil testing we would change the York centrifugals oil out
every year and hoped that it didn't need it more. Testing the oil took the
guess work out.

I also think its wise to check the quantity of oil in the system.


What gives?

tia

Peter H