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F0- External DC fan error (3-core terminal motor)
Explanation of
error
Cause:
Our frequency changing external unit uses the 3-lead-wire DC
motor, or “externally 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 control panel will indicate
“external DC fan error” when it detects imbalanced current on the three
lead wires of the driving motor.
Inspection path:
Is the DC fan stuck by foreign matters→Motor
terminal connectors→Main external control panel→Motor
Tools required
for inspection
Main external control panel in normal condition
Frequent
problematic part
Mechanical jam of external fan, main external control panel, external
DC motor
Inspection
procedure and
key points
1.
First exclude the possibility of mechanical jam of external fan
blades.
。
2.
Observe if the terminal of the fan is not connected firmly or the
order of lead wires is correct. If the external fan 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 fan 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 fan of
the main external control panel. The maintenance personnel may as
well prepare matched main external control panel before maintenance.
If the fan returns to normal after replacing the main control panel,
then it’s the main control panel problem; if it still indicates external
DC motor error, then replace the external DC motor.
Special attention
Unlike the 5-core internal DC motor, there will be a process of fan
blade position locking before the 3-core DC motor with external drive
starts to rotate. The fan blades will shake mechanically for 3-5 seconds
and then rotate slowly, which is normal phenomenon.
