Pressure Sensor Check - Daikin VRV EMERION RXYQ-AATJA Service Manual

SiUS342303E
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
Part 6 Service Diagnosis
Detected Pressure
P , P
H L
2
(kg/cm ) (MPa)
51.0 5.0
4.5
45.9
4.0
40.8
3.5
35.7
30.6 3.0
2.5
25.5
2.0
20.4
15.3 1.5
10.2 1.0
5.1 0.5
0
0
0
–5.1 –0.5
0 0.5
–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
sensor
White
Check
4.15
– × 0.5
3.0
1.7
– × 0.5
3.0
High
pressure
sensor
384