Service manual

Section 7 Refrigeration System
7-21
Freeze Cycle Suction Pressure High Checklist
Possible Cause Check/Correct
Improper installation • See “Installation/Visual Inspection Checklist” on page 7-10
Discharge pressure • Discharge pressure is too high, and is affecting low side (See “Freeze Cycle
Discharge Pressure High Checklist” on page 7-19)
Improper refrigerant charge • Overcharged
• Wrong type of refrigerant
Other • Non-Manitowoc components in system
• H.P.R. solenoid leaking
• Hot gas valve stuck open
• TXV flooding (check bulb mounting)
• Defective compressor
Freeze Cycle Suction Pressure Low Checklist
Possible Cause Check/Correct
Improper installation • See “Installation/Visual Inspection Checklist” on page 7-10
Discharge pressure • Discharge pressure is too low, and is affecting low side (See “Freeze Cycle
Discharge Pressure Low Checklist” on page 7-19)
Improper refrigerant charge • Undercharged
• Wrong type of refrigerant
Other • Non-Manitowoc components in system
• Improper water supply over evaporator (See “Water System Checklist” on
page 7-10)
• Loss of heat transfer from tubing on back side of evaporator
• Restricted/plugged liquid line drier
• Restricted/plugged tubing in suction side of refrigeration system
• TXV starving (check bulb mounting)
NOTE: Do not limit your diagnosis to only the items listed in the checklists.