Fan Warning/Trip on VFDs

Fan Warning/Trip on VFDs

Most VFDs are cooled by heatsink cooling fans. When the fan consumes a current which is out of the specified range (too low or high) the VFD will trip on a fan trip or warning. This is dependent on the setting in Pr/PRT79. In the event of a long term fan failure the VFD may trip on an overheat due to the insufficient cooling. 


Fan Troubleshooting Steps
  1. Set AD/ADV64=Always ON and check fan rotation. Then check that the fan is operating.
  2. If the fan is not operational, change out the fan(s).
  3. If a new fan is still not operational, check the pins for 24VDC. If missing 24VDC, there is an internal issue on the VFDs power supply.
​If all of the above steps were done, the fan is operational but a FAN warning/trip persists, the fan may be out of spec or the detection circuit can have an issue. Contact LS Tech Support for further assistance.