Designing for Success: The Imperative of Critical Speed in Electrical Motors - Industry Perspective

This paper aims to highlight the critical importance of adhering to specified guidelines for critical speed values in electrical motor design. The insights presented are based on an investigation into a vibration test failure during the factory acceptance test (FAT) for a high-voltage motor. The investigation revealed that the inaccurate machining of the motor was due to an erroneous critical speed value input, which did not comply with the company's guidelines. This discrepancy resulted in resonant vibrations exceeding the maximum allowable levels. This paper outlines the acceptable critical speed criteria according to the company's guidelines and underscores the essential role of these values in maintaining the design integrity of electrical machines.