Pressure Sensor Check - Daikin RXYQ-TA Series Service Manual

SiUS341615E
4.9

Pressure Sensor Check

CHECK 12
Detected Pressure
(psi) (kg/cm
725
653
580
508
435
363
290
218
145
72.5
0
–72.5
Voltage Measurement Point of the High Pressure Sensor
Microcomputer
Voltage Measurement Point of the Low Pressure Sensor
Microcomputer
Service Diagnosis
P , P
H L
2
) (MPa)
51.0 5.0
45.9 4.5
40.8 4.0
35.7 3.5
30.6 3.0
25.5 2.5
20.4 2.0
15.3 1.5
10.2 1.0
5.1 0.5
0
0
–5.1 –0.5
–0.5 0 0.5 1
Output Voltage V
A/D input
Make measurement of DC
voltage between these wires.
A/D input
Make measurement of DC voltage between these wires.
High Pressure (P )
H
Low Pressure (P )
L
1.5 2 2.5 3 3.5 4
(VDC)
, V
H L
+5 V
Connector for high
pressure sensor (Red)
(4)
(3)
(2)
(1)
+5V
Connector for low pressure sensor
(Blue)
(4)
(3)
(2)
(1)
4.15 4.15
P (MPa) = × V –
H H
3.0 3.0
1.7 1.7
P (MPa) = × V –
L L
3.0 3.0
1 MPa = 145 psi
P : High pressure (MPa)
H
P : Low pressure (MPa)
L
V : Output Voltage (High Side) (VDC)
H
V : Output Voltage (Low Side) (VDC)
L
Red
High
Black
pressure
sensor
White
Red
Black Low
pressure
White sensor
Check
× 0.5
× 0.5
302