Comparison Between LT VVFD VS MV Soft Starter

Best is a subjective term. VFDs for 2 x 250kW motor in low voltage will probably be more expensive than a single 6.6kV soft starter running two motors, so from an initial cost standpoint, the SS would be best. Smoothest start? VFD without question. A VFD can accelerate the conveyor at any speed stretched out over any amount of time. But having two VFDs allows you the flexibility to ensure that the motors are equally sharing the load, soft starters cannot do that. A 2.2kM conveyor belt will act like a rubber band then accelerating, so VFDs allow compensation where soft starters cannot. VFDs can also allow for some breaking capacity if any part of the conveyor goes down hill.

GO FOR

6.6kV RANGE 250MW VFD EITHER WITH VECTOR CONTROL OR DTC CONTROL FROM REPUTED MAKES EITHER ALLEN BRADLEY OR ABB.

PREFERABLY INDEPENDENT DRIVES FOR BETTER CONTROL AND CONDITION MONITORING/RELIABILITY.

6.6kV VFD are very expensive