Cause:
- DC link voltage has fallen during operation below the permissible value for "UDC_MIN" ("Power section" menu)
Remedial action:
- check the value set for parameter "UDC_MIN" in the "Power section" menu (factory setting: 450 V)
- check the dimensioning of the frequency inverter
- check the motor data
- if there is a power failure while driving, check the voltage of the 3 phases of the power supply