What will happen if transformers are operated at non-nameplate voltages?
A transformer is designed using specific ratios that relate to the rated KVA, primary voltage and secondary voltage proportionally. Operating a transformer above or below the nominally designed primary voltage will reflect a proportional increase or decrease in secondary output levels. Extreme caution must be observed when overvoltage levels exist. Excessive input voltage will cause higher core losses, increased noise and elevated temperatures. Overvoltages for any extended period of time have a significant effect on insulation breakdown and transformer failures. Transformers can be specifically designed for extreme voltage conditions if initial specifications state those requirements.
