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MANUFACTURER

There are several types of motor starters. The most common is the across-the-Line (full voltage) non reversing starter which is the most economical and most commonly used type of motor starter. Full voltage is applied to the motor for starting by use of a single motor contactor. Across-the line starting is accompanied by inrush currents up to 7 times higher than running current, and starting torque up to 3 times higher than running torque. The increased torque results in sudden mechanical stress on the machine which leads to a reduced service life. Reduced voltage starters are commonly used to reduce in rush current and high starting torque. Reversing starters change the direction of rotation with the addition of a second contactor to switch polarity in two off the three phases making the motor change direction. A combination starters is a basic starter with the addition of a disconnect switch and fuses or molded case breaker for short circuit protection. Reduced voltage (soft starts) reduce shock loads and sudden mechanical stress as well as high currents and current peaks that lead to high fixed costs charged by the power supply companies. They continuously control the motor voltage supply at a reduced rate during the start-up phase. This way, the motor is adjusted to the machine’s load behavior.