This is the primary use and the device is designed to withstand a maximum of 22 amps when operating a three-phase motor with a voltage of (380 - 440 volts) and a power of up to 11 kilowatts. At a voltage of 200 - 220 volts: the motor's amp capacity is about 18 to 20 amps. At a voltage of 380 - 440 volts: the motor's amp capacity is 22 amps.