Flooding

Improper system piping allows liquid to compressor - Correct piping

Defrost cycle improperly set or not operating correctly - Do not allow more than 1/3 of system on defrost at any time. Verify proper operation of defrost system.

Defective or improperly set expansion valve - Increase superheat or replace expansion valve.

Evaporator fan failure - Correct problem or replace evaporator fan