Troubleshooting by Remote Controller
SiUS281117
Service Diagnosis
179
Check Pressure Sensor
Measure the voltage (DC) between pins 1 and 3 of the connector.
CHECK 6
Outdoor unit PCB (A1P)
+5V
Connector Red
Red
Black
White
Pressure sensor
GND
Micro-computer
A/D input
Measure DC voltage here.
Detected Pressure
Output voltage (V
H
)
P
H
(Kg/cm²) MPa
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.5
1.5
2.5
-0.5
-0.5
0
1
2
3.5
3
4
V
DC
51.0
45.9
40.8
35.7
30.6
25.5
20.4
15.3
10.2
5.1
-5.1
0
0
P
H
= 1.38V
H
– 0.69
P
H
: Detected pressure (MPa)
V
H
: Output voltage (V)
P
H
This graph is available for both high pressure sensor
and low pressure sensor.
