Voltage variation impact on induction motor?

• Induction Motor voltage below name plate rating will result in decrease in the starting torque of the motor and increase in the full load temperature rise.
• On the other hand, increase in the supply voltage above the specified voltage will results in increase in the starting torque of the motor, increase in the inrush currents during starting and decrease in the power factor.
• Increase in the starting torque to above supply voltage results in acceleration of the coupling or driven equipment. Increase in the starting currents results in voltage drop in the bus connected to the motor. This effects the performance of the other loads connected to the bus.
• Supply voltage above the rating will have less impact on the induction motor compared to under voltage condition but if voltage above 110% of the rated voltage will saturate the stator iron (flux is proportional to voltage / frequency) thereby damaging the magnetic properties and increase in losses.