Thermo King SB-190 30, Manual

Page: 105 / 119

95
Refrigeration Diagnosis
Ra
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Hi
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Low
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Hi
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Low
su
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N
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it
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Re
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SYM
PTO
M
POSSIBLE CAUSES
• • • •
Overcharge of refrigerant
• • • • • •
Shortage of refrigerant
• • • • •
No refrigerant
•
Air through condenser too hot (ambient)
•
Air flow through condenser restricted
• • •
Air through condenser too cold (ambient)
• • •
Air in refrigerant system
•
Condenser fan blades bent or broken
•
Air short cycling around evaporator coil
•
Air through evaporator restricted
• • • •
Evaporator needs defrosting
• •
Compressor discharge valves leaking
• •
Compressor suction valves leaking
•
Too much compressor oil in system
•
Faulty oil pump in compressor
•
Faulty compressor drive coupling
•
Compressor bearing loose or burned out
• • • • •
Broken valve plate in compressor
• •
Expansion valve power element lost its charge
• •
Expansion valve feeler bulb improperly mounted
• • •
Expansion valve feeler bulb making poor contact