Carrier 42QHP09E8S Service Manual page 67

Remarks:
• Use a multimeter to test the DC voltage between 2 port and 3 port of outdoor unit. The red pin of multimeter
connects with 2 port while the black pin is for 3 port.
• When AC is normal running, the voltage is moving alternately as positive values and negative values.
• If the outdoor unit has malfunction, the voltage has always been the positive value.
• While if the indoor unit has malfunction, the voltage is a fixed value.
• Use a multimeter to test the resistance of the reactor which does not connect with capacitor.
• The normal value should be around zero ohm. Otherwise, the reactor must have malfunction.
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