Improve uptime with faster recovery from voltage dips

Tuesday, May 25, 2021

No matter how brief, power outages inevitably impact productivity. The good news is it is now easier to keep critical processes running reliably. Induction motors controlled by high-power VLT® drives can recover faster from mains drop-out, thanks to improvements in the flying start feature.


The flying start feature kicks in to catch a motor that is spinning freely due to a mains drop-out or windmilling. This function is especially relevant for centrifuges and fans. Flying start allows the drive to synchronize with an operating motor rotating at up to full speed in either direction. This prevents trips due to overcurrent draw. It also minimizes mechanical stress on the system since there is no abrupt change in motor speed when the drive re-starts.

Use the new improved flying start for induction motors running at speeds up to 132 Hz, with VLT® AutomationDrive FC 302, VLT® AQUA Drive FC 202, VLT® Refrigeration Drive FC 103, or VLT® HVAC Drive FC 102 running in VVC+ mode. New flying start is also active in VLT® AutomationDrive FC 302 when running in flux mode.

For induction motors running at speeds above 132 Hz, the flying start function will operate as before.

Benefits of the improved flying start include:

  • Reliable catch of the motor
  • Up to 4 times faster recovery
  • Minimal mechanical stress on the system

Further information