13.3 Diagnosis of defects on electric parts
(1)
Confirmation of trouble with controller
• If the "
alarm lamp
" lights or flickers, press the "
alarm switch
" . All errors that are currently occurring will
be displayed as symbols on the "
digital display
". Confirm the state with the operation switch turned
ON
.
• Note that error displays or abnormalities in operation may occur due to strong radio waves, etc. In this case, turn
the refrigeration unit off and on once and confirm the operation.
•
Always turn the operation switch OFF before inspecting the refrigeration unit.
– 47 –
Alarm
Digital display
Remedies
Unit state
lamp
(lit)
•
The fuse F
2
for the magnet clutch has blown.
Inspect and replace the fuse F
2
in the relay box.
•
The fuse F
3
for the condenser fan motor has blown.
Inspect and replace the fuse F
3
in the relay box.
•
The delivery temperature sensor is activated.
Through the sight glass, check for bubbling. If bubbling is
found, check the refrigerant circuit.
•
The fuse F
1
for the evaporator fan motor has blown.
Inspect and replace the fuse F
1
in the relay box.
•
The dual pressure switch has functioned.
For high pressure side
(1)
Confirm that the condenser fan is rotating, and if it is
not, inspect the wiring for disconnections.
(2)
Check whether dirt or mud is adhered on the condenser
coils. Use a brush and water to clean any dirt off.
For low pressure side
The refrigerant runs out. Check for the refrigerant leak, and
refill the refrigerant.
•
Broken wire in room temperature sensor or defective
connection contact.
Check the resistance value and wiring of the room temperature
sensor, and check the connector.
•
Short circuit in room temperature sensor.
Check the resistance value and wiring of the room temperature
sensor, and check the connector.
•
Delivery temperature sensor short circuit
Check the resistance, wiring and connector of the delivery
temperature sensor.
Normal
Unit stops
Unit stops
Unit stops
Unit stops
Unit stops
Unit stops
Operation
continues.
∗
1
1
2
3
4
5
7
ALARM
Room
temperature
displa
y
6
(Blinki
ng)
(not lit)
∗
2
Note:
(1)
∗
1 mark indicates that there are multiple abnormalities, and the indications are
done in preferential order of
1
,
2
··· as shown on the above table.
(2) *2
indicates the delivery temperature sensor of the compressor on the
engine side.
indicates the delivery temperature sensor of the compressor on the
motor pack side.
(3) Make sure to replace the fuse with genuine fuse with the same capacity as the
original.
Fuse installation position
