A National Power Laboratory (NPL) power quality study provides a clue. It showed an actual incident rate for disturbances large enough to corrupt data or destroy equipment. The study accumulated 450 site-months of power line disturbance data from 74 monitored locations in the US and Canada.
The above was by Charles Ruelle, NPL Director, in the Best Power Technology Inc. newsletter <i>"Horizons"</i> January 1992 issue. It points to why knowledgeable computer users opt for standby or backup power systems. The result is that consistent random computer problems are eliminated with an uninterruptable power system, UPS or SPS, standby power system. We've proven this time and again at State OES headquarters, where we've been able to peg specific computer failures to observed commercial power grid surges, lightning strikes and interruptions.