What does "starting torque" refer to?

Starting torque specifically refers to the amount of torque produced by a motor when it is initially powered on, before it reaches its operational speed. This is a critical aspect of motor performance because it indicates the motor's ability to overcome static friction and inertia when beginning to rotate. Motors designed with high starting torque are especially valuable for applications that require the motor to initiate movement against resistance, such as in heavy machinery or starting large fans.

In contrast, the maximum torque refers to the peak level of torque a motor can sustain, which may occur at various speeds depending on the motor's design but is not exclusive to the startup phase. Torque at maximum speed indicates the performance of the motor when it is running at its highest operational rate, which can be significantly lower than starting torque for certain types of motors. Finally, the torque generated during normal operation refers to the continuous torque output while the motor runs, which varies based on load conditions, and does not specifically address the initial torque produced at startup. Therefore, the definition of starting torque clearly aligns with the performance of the motor at the moment it is activated.