Daikin Super Multi Plus E-Series Service Manual page 400

Troubleshooting for Outdoor Unit
Troubleshooting
∗2: Voltage measurement point
∗1: Refer to "Thermistor Resistance / Temperature Characteristics" table on P407.
∗2: Refer to "Pressure Sensor, Pressure / Voltage Characteristics" table on P409.
388
Be sure to turn off power switch before connect or disconnect connector,
Caution
or parts damage may be occurred.
YES
Cooling
NO
The suction
pipe1 temp. minus low YES
pressure saturation
temp. is 20 °C or
higher.
NO
Resistance
is normal when
measured with the
thermistor (R3T) for NO
suction pipe1
disconnected from the
outdoor unit
PC board.
*1
YES
Is the
NO
low pressure sensor
correct?
YES
Outdoor unit PC board A1P
GND
Microcomputer
A/D input
*2 Measure voltage here.
YES
Low pressure is
0.25 MPa
or less.
NO
The
voltage of
X18A pins (2)
and (3) on main
YES
outdoor unit PC board
(A1P) is 1.0 VDC or
less. (Low pressure
sensor output
voltage) *2
NO
+5V
X18A
Red
Black
White
SiEN18-622
Out of gas, closing of stop
valve or refrigerant system
is clogged. Requires check
of refrigerant system.
Replace main outdoor unit
PC board (A1P).
Replace low pressure sensor.
Out of gas or refrigerant
system is clogged. Requires
check of refrigerant system.
Replace the thermistor.
Replace the low pressure
sensor.
Replace the outdoor unit
PC board (A1P).
(V2819)
(V2809)
Troubleshooting