What type of starter is commonly used for high-inertia load motors?

The choice of a capacitor starter for high-inertia load motors is particularly suitable because it provides a significant boost in starting torque, which is essential for overcoming the initial resistance of high-inertia loads. High-inertia loads require a higher torque at startup to accelerate to their operational speed, and a capacitor starter achieves this by introducing a phase shift in the motor's current.

This phase shift enhances the starting torque, allowing the motor to start smoothly even under heavier loads. The capacitor is temporarily connected in series with the motor's starting windings to create an additional phase, optimizing the motor's ability to handle the demands placed on it by high-inertia applications.

In contrast, while direct-on-line and full voltage starters apply full voltage directly to the motor with no added torque assistance, they may not provide sufficient starting torque for high-inertia loads, potentially leading to stalling. A star-delta starter, which is designed primarily for reducing starting current and torque in motors with lower starting torque requirements, would not be effective for accelerating high-inertia loads either, as it limits the initial available power.

Thus, the capacitor starter stands out as the most appropriate choice in this context, ensuring efficient and reliable operation of motors handling high-inertia loads.