![background image](http://html1.mh-extra.com/html/thermo-king/crr-20/crr-20_maintenance-manual_1104387158.webp)
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
Содержание CRR-20
Страница 4: ......