Voltage variation and unbalance are defined separately within NEMA MG-1. However, in real-life applications these conditions exist at the same time. In this paper we will discuss combined voltage variations and unbalances in order to come up with a range of optimal thermal operation. A range of multipliers will be generated covering over and under voltage conditions at different voltage unbalances assuming balanced phase angles and circuit impedance.
How to Evaluate an Electric Motor with Voltage Variance and Unbalance
