CSR-20 & CSR-40, September 1999
Refrigeration System Diagnosis and Service
Visual Inspection and Diagnosis Chart
6-3
Potential Problem
Alarm Codes
Inspect/Check for
Low Refrigerant Charge
-55, -56, -64 and
- Defective container insulation
(unit not cooling)
-82
- Poor fitting container doors
- Partial obstruction in high side
- Partial obstruction in low side or filter drier
- Iced or plugged evaporator coil
- Expansion valve feeler bulb improperly mounted, poorly insu-
lated or making poor contact
- Expansion valve power element lost its charge
- Shortage of refrigerant: Inspect refrigeration system for signs
of oil loss. Locate and repair leak.
- Compressor inefficient
- Expansion valve partially closed by ice, dirt or wax
Obstruction in Low or
-50, -51, -55, -56,
Frosted or sweating suction line:
High Side
-64, -82 and -85
- Expansion valve admitting excess refrigerant
- Evaporator coil needs defrosting
- Restricted airflow through the evaporator coil
Dry, warm suction line:
- Restricted filter drier
- Shortage of refrigerant: Inspect refrigeration system for signs
of oil loss. Locate and repair leak.
- Expansion valve partially closed by ice, dirt or wax
- Expansion valve power element lost its charge
- Modulation valve stuck closed
Frosted liquid line:
- Restricted filter drier
Hot liquid line:
- Expansion valve open too wide
- Shortage of refrigerant: Inspect refrigeration system for signs
of oil loss. Locate and repair leak.
High Refrigerant Charge
-50, -51 and -85
- Condenser coil dirty or airflow restricted
- Defective water pressure switch (option)
- Insufficient water flow rate or plugged water-cooled con-
denser-receiver tank (option)
- Restricted filter drier
- Restricted lines on high side
- Air in refrigeration system
- Overcharge of refrigerant: Install service valves and gauge
manifold set. Check system operating pressures. After all
other components have been checked, remove refrigerant
charge and weight in new charge
Hermetic Refrigeration System Visual Inspection and Diagnosis Chart
