wrong oil in vilter 400 series compressors

[roder]

shell s4-fr-f-68 has been added to some of our 400 series compressors(ammonia) that were using wax free mineral oil. not sure how much has been mixed in with each compressor or how long its been used.

[RANGER1]

Not sure 100% , but polyester oil might turn to grease like substance, I have been warned about one of these types of oil, so suggest mop out crankcase & change compressor oil charge.
Also oil return float etc
It's hydroscopic & for 134a & HFC refrigerants.

[sandybapat]

Roder

Could you please specify refrigerant and evaporating temperature?

Ranger1

I checked up with internet that this oil is developed for R134a & other HFC refrigerants. Could you please clarify as to the effect of using this oil for Ammonia (Of course other than possibility of moisture ingress) ?

[RANGER1]

http://www.centrogalileo.it/nuovaPA/Articoli%20tecnici/INGLESE%20CONVEGNO/UNIQEMA%20ingl.doc

There is a comment on oil turning to a solid in this article

[sandybapat]

Thanks Ranger1. The Article is quite informative.