Mitsubishi Electric CITY MULTI PUMY-P112VKM6 Service Manual page 93

8-8-2. High pressure sensor
■ The methods of comparing the high pressure sensor measurement and gauge pressure
By configuring the digital display setting switch (SW1) as shown in the figure below, the pressure as measured by the
high pressure sensor appears on the LED1 on the control board.
SW1
ON
OFF
1 2 3 4 5 6 7 8
The black square (■) indicates a switch position.
1. While the outdoor unit is stopped, compare the gauge pressure and the pressure displayed on the self-diagnosis
LED1, 2.
• When the gauge pressure is between 0 and 0.098 MPaG [14 psig], internal pressure is caused due to gas leak.
• When the pressure displayed on the self-diagnosis LED1, 2 is between 0 and 0.098 MPaG [14 psig], the connector
may be faulty or be disconnected. Check the connector and go to the method 4.
• When the pressure displayed on the self-diagnosis LED1, 2 exceeds 5.0 MPaG [725 psig], go to the method 3.
• If other than listed above, compare the pressures while the sensor is running. Go to the method 2.
2. Compare the gauge pressure and the pressure displayed on the self-diagnosis LED1, 2 after 15 minutes have
passed since the start of operation. (Compare them by MPaG [psig] unit.)
• When the difference between both pressures is within 0.25 MPaG [36 psig], both the high pressure sensor and the
control board are normal.
• When the difference between both pressures exceeds 0.25 MPaG [36 psig], the high pressure sensor has a prob-
lem. (performance deterioration)
• When the pressure displayed on the self-diagnosis LED1, 2 does not change, the high pressure sensor has a prob-
lem.
3. Remove the high pressure sensor from the control board to check the pressure on the self-diagnosis LED1, 2.
• When the pressure displayed on the self-diagnosis LED1, 2 is between 0 and 0.098 MPaG [14 psig], the high pres-
sure sensor has a problem.
• When the pressure displayed on the self-diagnosis LED1, 2 is approximately 5.0 MPaG [725 psig], the control
board has a problem.
4. Remove the high pressure sensor from the control board, and short-circuit between the pin 2 and pin 3 connectors
(63HS) to check the pressure with the self-diagnosis LED1, 2.
• When the pressure displayed on the self-diagnosis LED1, 2 exceeds 5.0 MPaG [725 psig], the high pressure sen-
sor has a problem.
• If other than listed above, the control board has a problem.
■ High pressure sensor configuration (63HS)
The high pressure sensor consists of the circuit shown in the figure below. If 5 V DC is applied between the red and the
black wires, voltage corresponding to the pressure between the white and the black wires will be output, and the value of
this voltage will be converted by the microprocessor. The output voltage is 0.078 V per 0.098 MPaG [14 psig].
Note:
• 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
Vcc Pin 1
Vout Pin 2
GND Pin 3
RD
WH
Vout
BK
63HS
3–1: 5 V (DC)
2–1: Output Vout (DC)
OCH790 _93
Control board side
Pin 3
Pin 2
Pin 1
OUTDOOR MULTI CONTROLLER
CIRCUIT BOARD
Pressure: 0–5.0 MPaG [725 psig]
5 V DC
Vout: 0.5–4.5 V
3
0.078 V/0.098 MPaG [14 psig]
2
MICRO
PROCESSOR
1
GND
Vout (V)
4.5
2.5
0.5
0
2.5 5
363 725
PRESSURE
(MPaG)
(psig)