AUX ASW-H09B5B4/FAR3DI-C3, Service Manual

Page: 41 / 101

38
(9) F0- Outdoor Unit DC motor error (3-core terminal motor)
Explanation of
error
Cause: Our frequency changing Outdoor Unit uses the 3-lead-wire DC
motor, or “Outdoor Unit driven DC motor” for short, after 2012. It has
no speed feedback circuit but 3 drive lead wires and its driving
principle is similar to that of the compressor. The main PCB will
indicate “Outdoor Unit DC motor error” when it detects imbalanced
current on the three lead wires of the driving motor.
Inspection path: Is the DC motor stuck by foreign matters→Motor
terminal connectors→Outdoor Unit main PCB→Motor
Tools required
for inspection
Outdoor Unit main PCB in normal condition
Frequent
problematic part
Mechanical jam of Outdoor Unit motor, Outdoor Unit main PCB,
Outdoor Unit DC motor
Inspection
procedure and
key points
1. First exclude the possibility of mechanical jam of Outdoor Unit
motor blades.
。
2. Observe if the terminal of the motor is not connected firmly or the
order of lead wires is correct. If the Outdoor Unit motor of the newly
installed air conditioner rotates reversely, first observe if the color
order of the three lead wires is correct, or change the order of any two
of the three lead wires of the motor to see if the motor can rotate in the
forward direction.
3
．
The DC motor of this scheme is relatively simple and reliable, so the
problem is more likely to be caused by the drive part of the motor of
the Outdoor Unit main PCB. The maintenance personnel may as well
prepare matched Outdoor Unit main PCB before maintenance. If the
motor returns to normal after replacing the main PCB, then it’s the
main PCB problem; if it still indicates Outdoor Unit DC motor error,
then replace the Outdoor Unit DC motor.
Special attention
Unlike the 5-core Indoor Unit DC motor, there will be a process of
motor blade position locking before the 3-core DC motor with Outdoor
Unit drive starts to rotate. The motor blades will shake mechanically
for 3-5 seconds and then rotate slowly, which is normal phenomenon.