SMC Networks HRS012-A-10 Series Service Manual page 41

14. Check for an input to the pressure sensor in the refrigerant circuit.
Check that the power is supplied to the refrigerant circuit pressure sensor.
Check voltage by contacting the probe of the tester directly to the connector external surface with
the "CN4" connector of the main board being inserted.
<Refrigerant circuit pressure sensor (for high pressure)>
Contact the positive probe to the pin number 22 and contact the negative probe to the pin number
10 of the "CN4" connector.
<Normal> Pin number 22 - Pin number 10: Voltage should be 5 VDC +/- 1V
<Refrigerant circuit pressure sensor (for low pressure)>
Contact the positive probe to the pin number 24 and contact the negative probe to the pin number
12 of the "CN4" connector.
<Normal> Pin number 24 - Pin number 12: Voltage should be 5 VDC +/- 1V
Fig. 3.3-15 Check of input to the refrigerant circuit pressure sensor
HRS Series
Chapter 3 Alarm Indication and Troubleshooting
HRX-MM-N007
3.3 Troubleshooting
3-25