Flickering lights are common signs. Generated by everyday electrical activity. It is able to scramble computer memory and hurt TV and radio reception. Lasting just millionths of a second, these are the most harmful of all power interferences. A momentary rise in voltage, starting inside or outside a home, it can fry sensitive electronic equipment like computers.
Most surges occur when devices with motors, such as hair dryers, shut off.
The energy being consumed by these devices is diverted elsewhere in the form of excess voltage. Surges also happen when the electric company switches power from one geographic area of the grid to another as supply and demand in the region changes. The best, least expensive way to deal with most sources of power interference is to plug sensitive, electronic equipment into a surge suppressor. Suppressors work by absorbing some of the electrical surge and diverting the rest to ground. When shopping for a surge suppressor, look for the following three things.