Mitsubishi Electric PUHY-RP200, Service Handbook

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[
IX
Troubleshooting ]
- 224 -
HWE10130 GB
[4] Troubleshooting Principal Parts
-1- High-pressure sensor (63HS1) and intermediate-pressure sensor (63HS2)
1. Compare the pressure reading on the high-pressure gauge and on the high-pressure sensor to check the high pres-
sure.
(Attach a pressure gauge to the check joint of the refrigerant service valve on the liquid side (BV2) to check the in-
termediate pressure.)
Set the digital display switch (SW1) as follows to have the high-pressure sensor reading displayed on LED1.
(1) While the sensor is stopped, compare the gauge pressure and the pressure displayed on self-diagnosis LED1.
1) When the gauge pressure is between 0 and 0.098MPa [14psi], internal pressure is caused due to gas leak.
2) When the pressure displayed on self-diagnosis LED1 is between 0 and 0.098MPa [14psi], the connector may be defective or
be disconnected. Check the connector and go to (4).
3) When the pressure displayed on self-diagnosis LED1 exceeds 4.15MPa [601psi], go to (3).
4) If other than 1), 2) or 3), compare the pressures while the sensor is running. Go to (2).
(2) Compare the gauge pressure and the pressure displayed on self-diagnosis LED1 while the sensor is running. (Com-
pare them by MPa [psi] unit.)
1) When the difference between both pressures is within 0.098MPa [14psi], both the high pressure sensor and the control board
are normal.
2) When the difference between both pressures exceeds 0.098MPa [14psi], the high pressure sensor has a problem. (perfor-
mance deterioration)
3) When the pressure displayed on self-diagnosis LED1 does not change, the high pressure sensor has a problem.
(3) Disconnect the high-pressure (intermediate-pressure) sensor from the control board, and check the pressure dis-
played on LED1.
1) When the pressure displayed on self-diagnosis LED1 is between 0 and 0.098MPa [14psi], the high pressure sensor has a
problem.
2) When the pressure displayed on self-diagnosis LED1 is approximately 4.15MPa [601psi], the control board has a problem.
(4) Disconnect the high-pressure (intermediate-pressure) sensor from the control board, short-circuit between pins No.
2 and No. 3 on connectors CN201 of 63HS1 and CN992 of 63HS2, and check the pressures displayed on LED1.
1) When the pressure displayed on the self-diagnosis LED1 exceeds 4.15MPa [601psi], the high pressure sensor has a problem.
2) If other than 1), the control board has a problem.
2. High-pressure/intermediate-pressure sensor structure
High-pressure/intermediate-pressure sensor is connected to a circuit as shown in the figure below. When a voltage of 5 VDC
is applied across red and black wires, the amount of voltage that corresponds to the pressure is output across white and black
wires, and the microcomputer takes in this voltage.
Output voltage is 0.071 V per 0.098 MPa [14 psi].
The pressure sensor on the body side is designed to connect to the connector. The connector pin number on the body side
is different from that on the control board side.
Body side Control board side
Vcc Pin 1 Pin 3
Vout Pin 2 Pin 2
GND Pin 3 Pin 1
1 2 3 4 5 6 7 8 9 10
ON
SW1
0
0.5 [73]
1.0 [145]
1.5 [218]
2.0 [290]
2.5 [363]
3.0 [435]
3.5 [508]
4.0 [580]
4.5 [653]
0 0.5 1 1.5 2 2.5 3 3.5
Output voltage (V)
Pressure
(MPa [psi])
Connector
63HS1
1 2 3
1
2
3
GND (Black)
Vout (White)
Vcc (DC 5 V)(Red)
Pressure 0 ~ 4.15 MPa [601psi]
Vout 0.5 ~ 3.5 V
0.071 V / 0.098 MPa [14 psi]