Troubleshooting for Outdoor Unit
SiBE18-821_C
410
Troubleshooting
Troubleshooting
∗
2: Voltage measurement point
∗
1: Refer to “Thermistor Resistance / Temperature Characteristics” table 2 on page 427.
∗
2: For pressure / voltage characteristics graph, refer to “Pressure Sensor” on page 429.
Cooling?
Is the low
pressure sensor
correct?
Low pressure is
0.25 MPa or less?
The voltage
between the pins 2
and 3 of X18A is 1.0 VDC
or less? (Low pressure
sensor output
voltage)
∗
2
Is the
suction pipe 1
temp. minus low pressure
saturation temp. 20
degrees or
more?
Resistance is
normal when
measured after
disconnecting the
thermistor
(R3T).
∗
1
Caution
Be sure to turn off the power switch before connecting or disconnecting
connectors, or parts may be damaged.
Refrigerant shortage,
closed stop valve or
refrigerant system is
clogged. Check the
refrigerant system.
Replace the main PCB
(A1P).
(R13042)
YES
YES
Replace the main PCB
(A1P).
YES
Refrigerant shortage or
refrigerant system is
clogged. Check the
refrigerant system.
YES
Replace the thermistor.
NO
Replace the low pressure
sensor.
NO
NO
NO
NO
YES
YES
Replace the low pressure
sensor.
NO
Main PCB A1P
Low pressure sensor
Measure the voltage here.
Microcomputer
A/D input
+5V
X18A (Blue)
Red
(R13043)
Black
White
GND
(4)
(3)
(2)
(1)
