Carrier 38MBRC Series - ELECTRICAL TESTS AND REMARKS; Multimeter Test Procedures

38MBRC: Service Manual
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
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REMARKS:
• Use a multimeter to test the DC voltage between the 2 port (or S or L2 port) and the 3 port (or N or S port) of the outdoor unit.
• The red pin of the multimeter connects to the 2 port (or S or L2 port) while the black pin is for 3 port (or N or S port).
• When the air conditioner is running normally, the voltage is moving alternately as positive values and negative values.
• If the outdoor unit malfunctions, the voltage has always had a positive value.
• If the indoor unit malfunctions, the voltage has always had a certain value.
• Use a multimeter to test the reactor resistance which does not connect with a capacitor.
• The normal value should be around zero ohm. Otherwise, the reactor has malfunctioned.
NOTE: Images and the values inside are for reference only. Actual condition and specific value may vary.
S and N
or
L2 and S
or
2 and 3