Service manual

6-3
State Malfunction occurrence Abnormal point Possible cause
E. Defrosting is operated q No trouble with the unit Excessive amount of moisture in cargo
frequently. w Defrosting solenoid valve Leakage
e Defrost timer Short setting timer
F. Refrigeration unit is q Container High cargo temperature
normal Poor thermal insulation or air leakage
A. Discharge pressure q Poor compression of compressor Abrasion of scroll slide section
is low. w Hot gas solenoid valve Valve leakage
e Defrosting solenoid valve Valve leakage
r Injection solenoid valve Valve blocked with contamination
B. Discharge pressure is q Evaporator fan Damages on fan blade
high Rotation failure of fan motor
Actuation of fan motor thermal protector
A. Hunting q Suction modulating valve Valve blocked with contamination
w Electronic expansion valve Valve blocked with contamination
B. Temperature q Suction modulating Valve blocked with contamination
continues dropping. valve Magnetic coil malfunction
Wire breakage
C. Temperature q Suction modulating valve Valve blocked with contamination
continues rising. w Electronic expansion valve Valve blocked with contamination
e Evaporator Insufficient evaporator air flow rate ( Refer to 3-B-y.)
r Drier Drier blocked with contamination
t Shortage of refrigerant charging amount Refrigerant leakage
A. Abnormal noise is q Compressor Worn-out of bearing
generated Abrasion of scroll slide section
Loose-tightened bolt
w Evaporator fan Loose fan motor set bolt
Deformation of fan motor set leg or loose-tightened bolt
Bending of fan motor shaft
Worn-out of fan motor bearing
Deformation of fan guide
Contact between fan and fan guide
e Condenser fan Loose-tightened fan motor set bolt
Bending of fan motor shaft
Worn-out of fan motor bearing
Deformation of fan guide
Deformation of condenser front panel
B. Abnormal vibration q Compressor Loose-tightened set bolt
generates w Piping Loose-tightened or missing of clamp bolt
Frosting area is less than It is normal, since the unit is controlled to make superheat degree small
one third of compressor surface. by electronic expansion valve.
Frosting area is Suction gas temperature sensor Defective contact of sensing section
more than one third of Deviation from specified sensor characteristics
compressor surface. Discharge gas Defective contact of sensing section
temperature sensor Deviation from specified sensor characteristics
Evaporator inlet sensor In back-up operation due to faulty sensor
Evaporator outlet sensor In back-up operation due to faulty sensor
Although water coupling q No actuation of water Insufficient cooling water flow rate
are connected, pressure switch Water pressure switch malfunction
condenser fan continues w No trouble with
To prevent temperature in the control box from rising,the condenser
rotating. the unit fan rotates at the ambient temperature of 30˚C or higher.
4 Inside temperature does not
rise (in the heating mode)
5 Control is unstable6 Abnormal noise or abnormal vibration.
8 Water-cooled operation is impossible
7 Abnormal frosting
on compressor
3 Inside temperature
does not drop.