What is the primary disadvantage of using a primary resistor starter?

Using a primary resistor starter introduces the issue of high heat generation as a primary disadvantage. This method involves adding resistors in series with the motor during startup to limit the inrush current. While this approach effectively starts the motor, the electrical energy dissipated in these resistors during operation converts to heat. If not managed properly, this heat can lead to overheating and damage to both the resistors and the surrounding components, potentially resulting in operational failures or reduced longevity of the starter system.

In contrast, other options may involve specific concerns but do not capture the main drawback of high heat generation tied to a primary resistor starter. For example, while excessive current draw can occur during startup, the resistors are precisely intended to mitigate this issue. Similarly, while increased complexity and limited torque control might present concerns in other systems or configurations, they are not hallmark disadvantages of a primary resistor starter in the same way that heat generation is. Thus, the heat generated due to electrical resistance is a critical consideration when evaluating the efficacy and safety of using a primary resistor starter.