Screw chiller suction pressure is too low
The condenser refrigerant liquid outlet valve is not fully open: the valve should be fully opened.
The refrigerant filter is clogged: the filter should be cleaned or replaced regularly.
Improper adjustment of the expansion valve or failure: need to adjust the correct or eliminate the fault, replace if necessary
Insufficient refrigerant filling: should be added to the specified amount
Excessive lubricating oil circulates in the chiller refrigeration system: the cause should be identified and reduced to a suitable value.