Troubleshooting Of Principal Parts - Mitsubishi Electric PURY-P200 Service Handbook

[4] Troubleshooting of Principal Parts

1. Pressure sensor
(1) Check for failure by comparing the sensing pressure according to the high pressure/low pressure
pressure sensor and the pressure gauge pressure.
Set SW1 as shown below to display the high and low pressure sensor data displayed digitally by the light emitting
diode LD1.
1 2 3 4 5
ON
(1) In the stopped condition, compare the pressure readings from the gauge and from the LD1 display.
(a) If the gauge pressure is 0~0.0098MPa, the internal pressure is dropping due to gas leakage.
(b) If the pressure according to the LD1 display is 0~0.0098MPa, there is a faulty contact at the connector, or it
is disconnected. Proceed to (4).
(c) If the pressure according to the LD1 display is 4.15MPa for high pressure or higher, proceed to (3).
(d) If other than (a), (b) or (c), compare the pressure readings during operation. Proceed to (2).
(2) Compare the pressure readings from the gauge and from the LD1 display while in the running condition.
(a) If the difference between the two pressures is within 0.098MPa, for high pressure and 0.03MPa for low
pressure both the affected pressure sensor and the main MAIN board are normal.
(b) If the difference between the two pressures exceeds 0.098MPa, for high pressure and 0.03MPa for low
pressure the affected pressure sensor is faulty (deteriorating performance).
(c) If the pressure reading in the LD1 display does not change, the affected pressure sensor is faulty.
(3) Disconnect the pressure sensor from the MAIN board and check the pressure according to the LD1 display.
(a) If the pressure is 0~0.098MPa for low pressure on the LD1 display, the affected pressure sensor is faulty.
(b) If the pressure is 4.15MPa for high pressure or higher, the MAIN board is faulty.
(4) Disconnect the pressure sensor from the MAIN board and short out the No. 2 and No. 3 pins of the connector
(63HS), then check the pressure by the LD1 display.
(a) If the pressure according to the LD1 display is 4.15MPa for high pressure the affected pressure, the
affected pressure sensor is faulty.
(b) If other than (a), the MAIN board is faulty.
(2) Pressure sensor configuration
The pressure sensors are configured in the circuit shown in
the figure below. If DC 5V is applied between the red and
black wires, a voltage corresponding to the voltage between
the white and black wires is output and this voltage is picked
up by the microcomputer.
The output voltage is 0.071V/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
Main board side
Pin 3
Pin 2
Pin 1
- 162 -
.
63HS
1 2 3
1
Connector
GND
2
Vout
3
Vcc (DC5V) (Red)
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
0 0.5 1
Pressure 4.15MPa
Vout 0.5 ~ 3.5V
0.071V/0.098MPa
(Black)
(White)
1.5 2 2.5 3 3.5
Output voltage [V]