Pressure Sensor Check - Daikin VRV RXYQ72-384XAYCA Service Manual

Check
4.9

Pressure Sensor Check

CHECK 12
(psi)
725
653
580
508
435
363
290
218
145
72.5
–72.5
Voltage Measurement Point of the High Pressure Sensor
Voltage Measurement Point of the Low Pressure Sensor
369
Detected Pressure
P , P
H L
2
(kg/cm ) (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
1.0
10.2
5.1 0.5
0
0
0
–5.1 –0.5
–0.5 0 0.5
Output Voltage V
Microcomputer
A/D input
Make measurement of DC
voltage between these wires.
Microcomputer
A/D input
Make measurement of DC voltage between these wires.
High Pressure (P
H
Low Pressure (P )
L
1 1.5 2 2.5 3 3.5
(VDC)
, V
H L
+5 V
X32A
+5 V
X31A
(4)
(3)
(2)
(1)
4.15
P (MPa) = × V
H H
3.0
1.7
P (MPa) = × V
L L
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
4
(4)
Red
(3) Black
(2)
White
(1)
Red
Black Low
pressure
White sensor
Part 6 Service Diagnosis
SiUS342004EB
4.15
– × 0.5
3.0
1.7
– × 0.5
3.0
High
pressure
sensor