Carrier 40MAHB Series Service Manual page 18

40MAHB: Service Manual
DIAGNOSIS AND SOLUTION (CONT)
Remarks:
• Use a multimeter to test the DC voltage between the 2 port (or S or L2 port) and 3 port (or N or S port) of the outdoor unit.
• The red pin of multimeter connects with 2 port (or S or L2 port) while the black pin is for 3 port (or N or S port) the unit is running normal, the
voltage is moving alternately as positive values and negative values.
• If the outdoor unit malfunctions, the voltage remains in a narrow positive value.
• If the indoor unit malfunctions, the voltage maintains a fixed value.
• Use a multimeter to test the reactor's resistance which does not connect with capacitor.
• The normal value should be around zero ohm. Otherwise, the reactor has malfunctioned. Check the reactor and make sure it is not shorted to the
ground.
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
S and N
L2 and S
2 and 3
18
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or