Mitsubishi Electric PUHY-P200 Service Handbook page 137

2. Low-pressure pressure sensor (63LS)
(1) Conduct the check comparing the pressure that is detected by the low-pressure pressure sensor and the
low-pressure gauge pressure.
The pressure that is detected by the low-pressure pressure sensor will be displayed on the LED screen, LD1 when
setting the digital shift switch (SW1) as shown below.
1 2 3 4 5
ON
(1) Compare the gauge pressure and the pressure that is displayed on LD1 while the sensor being stopped.
(a) When the gauge pressure is 0~0.098MPa
(b) When the pressure that is displayed on LD1 0~0.098MPa
the contact and proceed to (4).
(c) When the pressure that is displayed on LD is 1.7MPa or more
(d) When (a), (b), and (c) are not applied, compare the pressure while the sensor is operating.
(2) Compare the gauge pressure and the pressure that is displayed on LD1 while the sensor is operating. (Com-
pare by MPa unit.)
(a) When the difference between the both pressure is within 0.03MPa
sor and the main board are normal.
(b) When the difference between the both pressure is over 0.03MPa
defective (particular deterioration).
(c) When the pressure that is displayed on LD1 does not change
(3) Remove the low-pressure pressure sensor from the main board and check the pressure that is displayed on LD1.
(a) When the pressure that is displayed on LD1 is 0~0.098MPa
(b) When the pressure that is displayed on LD1 is approximately 1.7MPa
• When the outdoor temperature is
• When the outdoor temperature is over
(4) Remove the low-pressure pressure sensor from the main board, short circuit between the No.2 and No.3 con-
nector (63LS), and check the pressure that is displayed LD1.
(a) When the pressure that is displayed on LD1 is 1.7MPa or more
(b) When (a) is not applied
(5) Remove the high-pressure sensor (63HS) from the main board, insert it into the low-pressure pressure sensor
(63LS), and check the pressure that is displayed on LD1.
(a) When the pressure that is displayed on LD1 is 1.7MPa or more
(b) When (a) is no applied
(2) Low-pressure pressure configuration
The low-pressure pressure sensor is composed of the circuit
as shown in the right figure. When DC5V is applied between
Vcc and GND, the voltage that is appropriate for the pressure
between Vout and GND will be output, and it will be taken by
the microcomputer.
The output voltage is 0.173V/0.098MPa.
✻
The pressure sensor on the body side is specified for con-
nector connection.
The connector pin number on the body side is different
from that on the main board side.
Body side
Vcc Pin 1
Vout Pin 2
GND Pin 3
6 7 8 9 10
→
30˚C or less
30˚C →
→
The main board is defective.
→
The low-pressure pressure sensor is defective.
Main board side
Pin 3
Pin 2
Pin 1
- 135 -
Inner pressure drop due to gas leak.
→
Contact failure of the connector Check for
→
Proceed to (3).
→
Both the low-pressure pressure sen
→
The low-pressure pressure sensor is
→
The low-pressure pressure sensor is defective.
→
The low-pressure pressure sensor is defective.
→
→
The main board is defective.
Proceed to (5).
→
The low-pressure pressure sensor is defective.
→
The main board is defective.
63LS
1 2 3
Connector
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
→
Proceed to (2).
The main board is defective.
Pressure 0 ~ 1.7MPa
Vout 0.5 ~ 3.5V
0.173V/0.098MPa
1
GND (Black)
2
Vout (White)
3
Vcc (DC5V) (Red)
0 0.5 1 1.5 2 2.5
Output voltage [V]
3 3.5