Hello everybody, I am newbie at both the forum and refrigeration world. However I am starting the hard way, and need to explain serious damage to a screw compressor. The compressor has run for about 2 years until it finally got to this situation.

This is a NH3 VSD water chiller with a single compressor and plate type condenser/evaporator. The compressor was badly damaged and need to be scraped completely. Explanation by our contractors was liquid carryover, however they are reluctant to give a specific reason because (I guess) they provided the equipment (I think they were involved with the design) and start up.

Evidently something failed in regards to liquid separation / shutoff protection.

I would like to know from you guys what are the normal causes of liquid carryover into the compressor and what protections should be in place to either shut off/remove the liquid.

Thanks in advance