What is a key benefit of using an autotransformer starter in certain applications?

The key benefit of using an autotransformer starter is its ability to reduce the starting current of a motor. When a motor is started directly across the line, it can draw a very high amount of current, which may be several times its full-load current. This high inrush current can lead to voltage dips in the electrical system, stressing equipment and potentially causing damage.

An autotransformer starter reduces this inrush current by using taps on the transformer to supply a lower voltage to the motor at the start. By providing only a portion of the supply voltage during the initial phase of starting, the autotransformer effectively limits the current while allowing the motor to accelerate gradually. This controlled starting method not only reduces stress on the motor but also protects the electrical supply system.

In contrast, other options do not provide benefits aligned with the use of an autotransformer starter. Increased complexity of the circuit may be a concern but does not represent a benefit. Lower application costs could be linked to different starting methods that do not require such components. Unstable operation during start is contrary to what an autotransformer aims to achieve, which is a smooth and stable starting process.