New oil + old oil = ?

[Collie]

Hi guys, have to carry out oil change on a copeland semi hermetic compressor. Have no idication as to what type of oil is currently in the compressor. When I rang up suppliers i was asked what the oil viscosity was and what type etc., but I havent looked after this unit before so....??? What would the implications be if two POE oils suitable for 407c and those running temps but of different viscosities being put into the same system?? I thought it would be your operating temps that would determine the viscosity level required no? am I way off? thanks guys

Heres the details if anyone knows anything;

DWM COPELAND/ D8SJ1-600X AWM/D

running on R407c, CIAT Air cooled, water chiller with a return water setpoint of +5 celcius. Anymore info required to help me determine a suitable oil?

[chemi-cool]

The X after the 600 indicates that the oil is POE.

[Collie]

thanks, actually found the manual online for download. cant post the link up until i have more posts

[exxu]

Copeland uses Mobil Arctic EAL-22-CC oil
in their compressors.