Forensic Engineering Expert Witness On Power Surges Part 1

In Identifying the Source of a Power Surge, forensic engineering expert witness Mamoon Alyah, P.E., answers the question “Is it possible to differentiate between lightning related surges and artificially generated electrical surges?”

A power surge is a condition where there are voltage variations from normal levels (110 Volts for a single phase system). These variations can be caused naturally by events such as lightning or artificially by many different events, ranging from simple power interruptions to significantly more complex events such as harmonics on the power line. Both sources of surge can cause similar types of damage to equipment including: premature failure of motors, computer and communication equipment mis-operation (lockups), loss of equipment following a thunderstorm and other symptoms of failure.

There are subtle, but significant differences between the nature of damages caused by the two types of surge (artificially vs. naturally generated). The cause of these differences is related to surge magnitude and the duration of the surge. Magnitude refers to the amount of energy contained in the power surge, while duration refers to the amount of time the power surge was sustained.