Warnings /Alarms 8 in VLT Micro Drive FC51 - means DC under voltage comes when the DC-link voltage drops below the undervoltage limit, the drive checks for 24 V DC back-up supply.

Cause & Remedy : Check that the supply voltage matches the drive voltage.

1. If no 24 V DC back-up supply is connected, the drive trips after a fixed time delay.

2. The time delay varies with unit size.

3. DC-link voltage drops below the voltage warning limit.