What action is first recommended for a motor that shows signs of overheating?

When a motor shows signs of overheating, the first action recommended is to inspect for obstructions in airflow. Adequate airflow is essential for maintaining the correct operating temperature of an electric motor. If airflow is restricted due to dust, debris, or other physical obstructions, the motor can overheat because it relies on this airflow for cooling. By addressing potential airflow issues first, one can often solve the overheating problem without resorting to more drastic measures such as replacing the motor or modifying operating conditions.

The other options might be relevant after assessing the airflow. For instance, while replacing the motor might be necessary if it's damaged beyond repair, it should not be the first step without investigating simpler potential causes. Increasing lubrication might help if the motor is overheating due to friction or wear, but this doesn't address issues related to airflow obstructions. Reducing the operating voltage can also prevent overheating, but it's more of a workaround than a direct solution to the underlying cause, which is often related to airflow. Thus, inspecting for airflow obstructions is the most logical and effective first step in troubleshooting an overheating motor.