Thermo King MD-MT, Operator'S Manual

Page: 146 / 192

Refrigeration Diagnosis
146
• • Expansion valve open too much
• • Expansion valve closed too much
• • Expansion valve needle eroded or leaking
• • • Expansion valve partially closed by ice, dirt or wax
• • • Liquid refrigerant entering compressor
• • Restricted line on the low side
• • • • Restricted line on the high side
• • • • Restricted drier
• Evaporator fan stays running
• • • Evaporator fan not running
• Discharge service valve back seated
• Suction service valve back seated
• • • • • • • Faulty CIS
• • • • • Faulty HGS
• • Loose or broken electrical connections
• • • • • Thermostat faulty
• • • • Compound pressure gauge out of calibration
• Leaky receiver tank outlet valve
• • • • • Leaky check valve
• • • • Faulty check valve
• Leaky receiver tank pressure solenoid (RTPS)
• • Closed receiver tank pressure solenoid (RTPS)
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Possible Causes