Carrier 40MAHB Series Service Manual page 22

40MAHB: Service Manual
DIAGNOSIS AND SOLUTION (CONT)
Outdoor DC Fan Motor (DC motor that controls the chip on the PCB)
1. Release the UVW connector. Measure the resistance of U-V, U-W, V-W. If the resistance is not equal to each other, the fan motor is faulty and
must be replaced. Otherwise, proceed to step 2.
2. Power on the unit and when the unit is in standby, measure the pin4-5 voltage in the feedback signal connector. If the value is not 5V, change the
PCB. Otherwise, proceed to step 3.
Rotate the fan by hand, measure the pin1-5, pin 2-5 and pin 3-5 voltage levels in the feedback signal connector. If any voltage is not in the positive volt-
age fluctuation, the fan motor is faulty and must be replaced.
Fig. 20 — Outdoor DC Fan Motor (DC motor that controls the chip on the PCB)
NO.
Color
Signal
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
1 2
Orange Grey
Hu Hv
Color Red
Signal W
3 4
White Pink
Hw Vcc
Blue Yellow
V U
22
5
Black
GND