coolpak 6000 compressor oil cct fail error

The heat exchanger inside of the may be clogged and a good way to try to clear it is to reverse the incoming water lines. With that said it is usually the incoming water from either temp or flow issues.

Basically, this error indicates that oil cooling circuit works not good enough. It may be due to compressor capsule itself overheating, due to oil leak, due to congested heat exchanger, etc.
If everything is fine with cooling (including heat exchanger cleaned from dirt) and compressor was never maintained within 8-10 years, it's standard error for aged Coolpak6000 and HC-10 compressors with vertical compressor capsule.
You can try to add some oil and it might help for a while (if your adsorber is new and displacer have to be replaced soon as it may induce much faster oil contamination of gas lines and coldhead), but usually such compressors need full maintenance, including cleaning and full oil exchange.
Every cryoservice guy would recommend that.

Right on site I'd
clean water heat exchanger first,
look for any possible oil leaks,
check resistance of compressor motor windings or checked compressor capsule somehow
and then
if compressor is aged and oil in sight glass is not sufficiently clean (i.e. colored brown, green, etc.) look for cryo-repair company.

I think the coolant doesn't flow throught the compressor. Possible are: (1) pipes bended or internally blocked (2) heat exchanger is blocked. Remove water outlet and check real flow and temperature. Check also outlet water pipe. (I had blocked this pipe one time) In second case unit has to be replaced

Does any one has a service manual for the Collpak 6000 ?
If so, please send it to: fabio@novacorp-sa.com
Thanks