The allowable frequency deviation above or below the value stamped on a motor's nameplate is what percentage?

The allowable frequency deviation for motors is typically set at 5% above or below the rated frequency indicated on the nameplate. This margin allows for minor fluctuations in electrical supply without significantly impacting the motor's performance or efficiency.

Understanding this percentage is crucial for wastewater operators, as motor operation is directly linked to the effective and efficient functioning of wastewater treatment processes. If the frequency deviation exceeds the 5% threshold, it could lead to issues such as overheating, increased wear, and ultimately, a reduction in the lifespan of the motor, which can cause disruptions in the treatment process.

This 5% deviation standard is widely accepted and reflects a balance between operational flexibility and the need to maintain reliable and consistent performance of electric motors in various applications, including those found in wastewater facilities.