Troubleshooting Outdoor Unit Fan Problems - Mitsubishi Electric HP120TNU-A Service Handbook

[8-7 Troubleshooting Outdoor Unit Fan Problems ]

8-7

Troubleshooting Outdoor Unit Fan Problems

(1) Fan motor (common items)
The number of revolutions of the outdoor fan is controlled by inverter. Check the number of revolutions of the fan while mon-
itoring the inverter output indicated by the self-diagnosis LED.
When starting the fan, the fan runs at full speed for 5 seconds.
When setting the DIP SW4 (when SW6-10 is set to OFF) as shown in the figure below, the inverter output [%] will appear.
100% indicates the full speed and 0% indicates the stopping.
ON
1 2 3 4 5 6 7 8 9 10
As the revolution of the fan changes under control, at the interphase or when the indoor unit operation capacity is low, the
revolution of the fan may change.
If the fan does not move or it vibrates, Fan board problem or fan motor problem is suspected. When checking the fan motor
for problems by shutting down the power, be sure to disconnect the motor wire from the fan board. If a short-circuited fan board
malfunctions, it will keep the fan motor from rotating smoothly. For details, refer to the following page(s).
[8-10-6 Checking the Fan Motor for Ground Fault and Coil Resistance Problems]
[8-10-7 Checking the Fan Board Error Detection Circuit at No Load]
[8-10-8 Checking the Fan Board for Damage at No Load]
[8-10-9 Checking the Fan Board for Damage with Load]
HWE18220_GB
Fan 1
SW4
ON
1 2 3 4 5 6 7 8 9 10
The figure at left shows that the switches 1 through 5 are set to ON and 6 through 10 are set to OFF.
Fan 2
SW4
ON
1 2 3 4 5 6 7 8 9 10
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