Resistance starters are switched for starting three-phase asynchronous machines with wound rotors in the motor's rotor circuit. The drive train is accelerated by reducing the starter resistance depending on the motor slip.
The variety of resistor configurations allows for a broad range of applications for the various starter types.
- Oil rheostat. Suitable for powers up to 20.000 kW and rotor voltages 5000 V. The resistive values are studied in the design stage and so remain fixed.
- Liquid rheostat. Suitable for power up a14.000 kW and rotor voltage 3500V. By changing the concentration of salts in electrolyte change the resistance value.