Soft starters are robust electronic control devices for starting three-phase asynchronous machines smoothly. Two of the three motor phases are influenced by the IR9027 by phase control in such a way that the current in these phases rises steadily. The motor torque behaves in exactly the same way during start-up. This guarantees that the drive can start up without jerking.
It is impossible for drive elements to be damaged, because the abrupt starting torque caused by direct starting is not generated.
A marked reduction of starting noise is also perceived. Slippage or tipping over of items being conveyed on belts is avoided.
After starting, the power electronics are bridged via an internal relay contact to minimise losses in the device.
Machines with gear, belt and chain drives
Conveyor belts, fans, pumps, compressors
Packaging machines, door operating mechanisms