Daikin RXQ12AHR, Service Manual

Page: 304 / 321

Check SiAF341904E
298 Part 6 Service Diagnosis
6.9 Pressure Sensor Check
CHECK 12
Pressure Sensor and Voltage Characteristics
Voltage Measurement Point of the High Pressure Sensor
Voltage Measurement Point of the Low Pressure Sensor
High Press u re (P
H
)
Lo w Press u re (P
L
)
O u tp u t V oltage V
H
, V
L
Detected Press u re
40. 8
35.7
30.6
25.5
20.4
15.3
10.2
5.1
–5.1
0
45.9
51.0 5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
–0.5
–0.5 0 0.5 1 1.5 2 2.5 3 3.5 4
( V DC)
(kg/cm
2
)(MPa)
P
H
, P
L
P
H
(MPa) = × V
H
– × 0.5
P
L
(MPa) = × V
L
– × 0.5
P
H
: High press u re (MPa)
P
L
: Lo w press u re (MPa)
V
H
: O u tp u t V oltage (High Side) ( V DC)
V
L
: O u tp u t V oltage (Lo w Side) ( V DC)
4.15
3.0
4.15
3.0
1.7
3.0 1.7
3.0
+5 V
(4)
(3)
(2)
(1)
Red
Black
W hite
X32A (Red)
High
press u re
sensor
Microcomp u ter
A/D inp u t
Make meas u rement of DC
v oltage b et w een these w ires.
+5 V
(4)
(3)
(2)
(1)
Microcomp u ter
A/D inp u t
Make meas u rement of DC v oltage b et w een these w ires.
X31A (Bl u e)
Red
Black
W hite
Lo w
press u re
sensor