Service manual

State Malfunction occurrence Abnormal point Possible cause
C. Condenser fan rotates, q Activation of  Short circuit of condenser fan motor
but evaporator fan and high-pressure switch  Wrong installation of condenser fan
compressor do not (Water cooled  Reverse rotation of condenser fan
rotate. condenser type) Insufficient cooling water flow rate
 Water-cooled condenser blocked with scale
w Overcurrent due to overload operation, etc.
e Abnormal low Electronic expansion valve: poor contact of connector
pressure drop Electronic expansion valve: incorrect opening
Electronic expansion valve: blocked
Suction modulating valve: blocked
Dryer: blocked
r Abnormal discharge Hot gas solenoid valve: coil wire broken
gas temperature Injection solenoid valve: closed
Injection capillary tube: blocked
High pressure increasing due to overload
A. Suction pressure is q Poor compression of compressor Abrasion of scroll slide section
high w Hot gas solenoid valve Valve leakage
e Defrosting solenoid valve Valve leakage
r Discharge gas Valve leakage
by-pass solenoid valve
t Electronic expansion valve Electronic expansion valve malfunction
Poor contact of connector
y Injection solenoid valve Valve leakage
B. Suction pressure is q Liquid solenoid valve (Not opened) Solenoid valve coil malfunction
excessively low w Shortage of refrigerant charge Refrigerant leakage
e Drier Drier blocked with contamination
r
Suction modulating valve Coil wire breakage
Disconnection of connector
t Electronic expansion valve Valve blocked with moisture
Valve blocked with contamination
Breakage of coil lead wire or disconnection of connector
Lead wire breakage or miss-mounting of evaporator inlet or outlet sensor
Electronic expansion valve malfunction
y Evaporator Abnormal frosting
Insufficient air flow rate in the evaporator
 Air passage blocked by foreign material
 Evaporator fan motor malfunction
 Evaporator fan damage or fall out
 Air short circuit around the evaporator
 Reverse rotation of evaporator fan motor
C. Economizer circuit Economizer solenoid valve Solenoid valve coil malfunction
does not function Valve blocked with contamination
D. Defrosting is not q Manual defrost key Poor contact of connector
initiated. w Evaporator outlet sensor Incorrect installation of sensor
e Defrosting solenoid valve Valve blocked with contamination
Valve coil malfunction
r No trouble with unit Defrost interval is set to 99 H
(Demand/defrost setting)
6-2
2 Unit operates but soon stops
3 Inside temperature does not drop.
Electronic overcurrent
protection device, PT/CT
board actuation