Refrigeration oils and viscosities

[ozonesafe]

Dear gentlemen. This is my first post in your forum. I just started working as refrigeration general helper for a local frozen food supply company. My supervisor is not very computer-literate so he asked me to do some research in regards to refrigeration oils. Copeland requires the use of ULTRA32-3MAF oil in many of their compressors, but there is a poor availability of this oil locally, besides being extremely expensive. I was not able to pinpoint the SUS/ISO number for this particular oil, but on the web I found an equivalent oil EMKARATE RL32-3MAF with an 150/32 viscosity. I have found with the local suppliers a lot of 300 viscosity oils which are suppose to be of more general use (piston, centrifugal, screw, rotary) than the copeland product, that is why they offer it. I also found a Thermo King oil 203-513 which is indeed a 150/32 but for mobile equipment. My questions are: is it possible to use a 300 oil in place of a 150/32 ?, Are mobile equipment oils similar to those of stationary compressors ?, Are all 150/32 oils compatibles, I mean can they mix, or it is necessary to drain all the oil from a previous manufacturer before adding another manufacturer´s product? Thanks for any replies.

[monkey spanners]

The RL32 MAF oil is a special oil made for copeland compressors, it has additives specific to copeland. This is signified by the MAF in the oil name.
Generally different brands of oil should not be mixed as the different additives can cause foaming etc so if you plan to change oil brands it would be good to get as much of the old oil out as possible.
I would not advise changing to a different viscosity oil, copeland will have designed their compressor to run on 32 grade for a reason.

[mbc]

main thing to choose oil is a evaporator temp. oil should have good viscosity at this temp and can return from evaporator to compressor , then you look for advices of compressor manufacture what they say .
do not mix different oil together