Overvoltage protection for distribution and low-voltage equipment experiencing sustained overvoltages

The increased occurrence of temporary overvoltages caused by commingling in over-built systems is a growing concern to electric utilities and end-users. These events are usually caused by transmission or sub-transmission lines dropping and contacting distribution lines during storms and traffic accidents that damage power poles. This paper discusses the effects of, and solutions to, these overvoltages. Protection solutions analyzed include primary arresters, secondary arresters and transformer core saturation.