Thermo King CRR-20, Руководство по обслуживанию

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8-8 Refrigeration Diagnosis Diagnosis
CRR-20 & CRR-40, September 1999
Condition Possible Cause Remedy
Compressor loses oil Refrigerant leak Repair leak and recharge
Compressor oil migrates Short cycling See “Unit short cycles” under
to system Mechanical Diagnosis
Rapid cycling between Air short cycling through evaporator Check and correct cargo load
Cool, Null and Heat
modes
Controller out of calibration Recalibrate or replace controller
(see Diagnosis Manual for Thermoguard
µ
P-D Microprocessor Controller, TK 41230)
Short cycling See “Unit short cycles” under Mechanical
Diagnosis
Evaporator pressure regulator (KVQ) Repair or replace valve
valve stuck closed or defective
Hot liquid line Shortage of refrigerant Repair or recharge
Expansion valve open too wide Adjust or replace expansion valve
Frosted liquid line Liquid line service valve partially Open valve or remove restriction
closed or restricted
Restricted dehydrator or in-line filter Replace dehydrator or in-line filter
Frosted or sweating Expansion valve admitting excess Check feeler bulb and adjust expansion
suction line refrigerant valve
Evaporator coil needs defrosting Check defrost circuit including controller
and evaporator coil sensor
Evaporator fan does not operate See “Evaporator fan motor does not oper-
ate” under Mechanical Diagnosis
Unit in vacuum. Frost on Ice plugging expansion valve Apply hot wet cloth to expansion valve.
expansion valve only screen or orifice Moisture indicated by increase in suction
pressure. Replace dehydrator