The speed changes steplessly in the control range when the master switch is operated. The crane driver only detects the end of the control range through latching of the master switch. Furthermore, the final stage is reached sub-synchronously or super-synchronously, depending on the load, by traversing the characteristics that are determined by the resistor increments. Current control is always operating to ensure that the set maximum torques are not exceeded. It goes without saying that the circuits are protected against reversal.

Control characteristics for hoists

Up to 4 rotor resistor switching stages can be provided. If less than 4 stages are implemented, the top stages (S3/S4) remain unused.

If the upper stages S3/S4 are not used, the over-synchronized speed increases in accordance with the parameterized characteristic on lowering. This must be taken into account when selecting overspeed protection. For this reason, a speed corresponding to the characteristic can also only be achieved during lifting.

Control characteristics for gantries

Up to 4 rotor resistor switching stages can be provided. If less than 4 stages are implemented, the top stages (S3/S4) remain unused.