Vaccum Starters are offered in three classifications. They are NEMA rated devices up to 600 Vac, Special Purpose rated devices up to 1500 Vac and Mining rated devices rated up to 1500 Vac. Each device is tested to different standards to serve their market. Typical applications include full voltage control of three-phase squirrel cage motors, primary control of low-voltage wound rotor motors and circuit switching for low-voltage capacitors for power factor improvement.