Power lines can send surges into your home when they are struck by lightning, downed by car accidents, maintenance mishaps, or restoration of power after an outage can cause voltage spikes that enter your home's wiring system on the way to ground. Therefore, it's advisable to have a "whole house" surge protector at your meter or in-line surge protection on sensitive electronics.

However, most surge damage is a result of transient voltage generated from within your home. Large appliances such as air conditioners and refrigerators draw a lot of power while running. What happens to that extra electricity when the motor cycles off? It dissipates throughout the wiring system in your home as it searches for ground. While these small surges go unnoticed, over time they degrade the circuit boards, shortening the lifespan of your electronics. Therefore, it's advisable to have plug-in "point-of-use" surge protectors at the receptacles that your electronics are plugged into.