It's been a while since I've actually done refrigeration work, but if the system isn't brought to a sufficient vacuum, it won't boil all the water out, and some non-condensible gasses will be left in.
I'll go with 'A'. 200 microns sounds familiar, but I could be way off.
I don't think a closed system could be pulled into enough of a vacuum to cause damage, in fact, it must be pulled into a pretty deep vacuum before it can be charged with refrigerant.
Leaving water and other icky stuff in it will dramatically shorten its life.
Rob
I'll go with 'A'. 200 microns sounds familiar, but I could be way off.
I don't think a closed system could be pulled into enough of a vacuum to cause damage, in fact, it must be pulled into a pretty deep vacuum before it can be charged with refrigerant.
Leaving water and other icky stuff in it will dramatically shorten its life.
Rob