What is the term given for a motor that runs at a speed where vibration occurs?

The term "critical speed" is used to describe the speed at which a motor's components may experience resonant vibrations. This occurs when the frequency of operation aligns with the natural frequency of the system, leading to amplified vibrations. Identifying critical speed is crucial because vibrations can lead to excessive wear, potential failure, or damage to the motor and connected equipment.

At critical speed, the motor operates in a condition that can significantly affect its performance and longevity. Operators and technicians aim to avoid this speed through proper design, maintenance, and monitoring practices. Understanding critical speed helps in implementing effective vibration control measures and ensuring smooth operation across the motor's performance range.