Starting rheostats are used to limit motor starting current and reduce stress on the electrical network.
Depending on the driven equipment and operating conditions, the appropriate type can be selected:
They are custom-designed according to customer requirements.
These units provide stepwise starting of wound-rotor (slip-ring) induction motors with power ratings up to 6.4 MW.
They consist of resistor banks installed in enclosures with protection ratings IP00, IP21, or IP23. Other enclosure types are available upon request.
Optionally, they can be equipped with a step control system located in a separate control cabinet.
Advantages
Applications
Oil-filled starting rheostats provide stepwise starting of wound-rotor induction motors by gradually removing resistance from the rotor circuit during acceleration.
They are suitable for high-power applications where frequent starts are not required.
Cast iron resistor elements are immersed in transformer oil, which provides both insulation and heat dissipation.
They support motor starting up to 6400 kW.
Advantages
Applications
Liquid starting rheostats provide smooth, stepless motor starting.
They are used in applications requiring high starting torque but not speed control.
The resistive medium is an electrolyte (Na₂CO₃ solution), which also acts as a heat sink.
A system of movable electrodes controlled by a PLC enables gradual resistance reduction during startup.
They support motors up to 13,500 kW.
Advantages
Applications
