Thermo King SPECTRUM TS Series - Expansion valve feeler bulb making poor contact; Expansion valve open too much; Expansion valve closed too much; Expansion valve needle eroded or leaking

Refrigeration Diagnosis
166
• • • Expansion valve feeler bulb making poor contact
• • 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 shutter open
• • • Evaporator shutter stuck closed
• Suction service valve back seated
• • • • • • • Faulty CIS
• • • • • Faulty Hot Gas Solenoid
• • Loose or broken electrical connections
• • • • • Thermostat or thermometer out of calibration
• • • • Suction pressure gauge out of calibration
• Leaky receiver tank outlet valve
• • DPR Valve Faulty
Rapid cycling between Cool and Heat Unit cools in Heat and Defrost cycle Unit heats in Refrigeration cycle High head pressure Low head pressure No head pressure High suction pressure Low suction pressure No suction pressure Unit operating in a vacuum Receiver sight glass empty Suction line frosting back Unable to pump down system Unable to pull vacuum in low side Unable to hold vacuum in low side Noisy compressor Unit not refrigerating Unit not heating or defrosting
Symptom
Possible Causes