Both ways, depending on the circumstances… A violent electrical storm can induce enough surge energy into power lines to destroy your computer in an instant, if left improperly protected. Smaller, internally generated surges can, over time, “wear out” delicate circuits, causing intermittent problems, and slowing down the operation of a system. Series Mode surge suppression technology, as designed by ZERO SURGE Inc., employs a surge reactor that serves as a power line filter, much like the oil filter in your car. The surge reactor filters out damaging energy, just as your oil filter removes impurities that can destroy your engine over time. The result with a good oil filter or a good power line filter is longer, trouble-free operation.