What type of manual starter is used for three-phase motors?

The integral horsepower starter is specifically designed for three-phase motors due to its ability to handle higher power requirements and provide the necessary torque at startup. These starters are capable of managing the substantial inrush current that occurs when three-phase motors are energized, ensuring a smooth and controlled start.

Integral horsepower starters are typically equipped with components like overload protection and contactors that can efficiently support the operational demands of larger motors, making them ideal for industrial applications. The design of these starters allows them to provide reliable performance and protection against electrical faults, which is essential for maintaining the longevity and efficiency of three-phase motors.

In contrast, other types of starters, such as capacitor starters, are better suited for single-phase motors and are intended to provide additional starting torque for those applications. Open-type starters can lack the necessary protective features required for three-phase motors, which increases the risk of motor damage during operation. Resistance starters, while they can be used for some three-phase applications, generally do not provide the optimal starting conditions needed for larger motors like those classified as integral horsepower.