Ec 72 (Lack Phase Failure Of Outdoor Dc Fan Motor Diagnosis And Solution) - MrCool DIY-MULTI2-18HP230C Service Manual

8.16 EC 72 (Lack phase failure of outdoor DC fan motor diagnosis and solution)

Description: When the three-phase sampling current of the DC motor is abnormal, especially when the current of one
or more phases is always small and almost 0, the LED displays the failure code.
Recommended parts to prepare:
• Connection wire
• Fan motor
• Outdoor PCB
Troubleshooting and repair:
Power off,then restart the unit
2 minutes later.Is it still
displaying the error code
Yes
Check the wiring of fan
motor.Are all the connections
good?
Yes
Check whether the three-
phase resistance of the fan is
symmetrical
Yes
Check the fan three-phase
output for obvious open circuit
Yes
Trobule is solved

No
No
No
No
Troubleshooting 51
The unit operates
normally
Correct the connections
Replace the fan motor
Replace the main PCB
