What Is A Power Surge?  An electrical surge is a short duration, high energy impulse that is sent through a normal electrical power system whenever there is a sudden change in the electrical circuit.

Where Do They Come From?  Lightning is the most obvious source, but surges also originate from normal utility switching operations, or the unintentional grounding of electrical conductors such as when a power line falls to the ground.

How Does Circuit Switching Cause A Surge?  These surges happen when a sudden change of electrical circuit occurs. A simple example is when you turn on a light switch.

Inside Job.  Power surges can also come from inside a building from air conditioners, machinery, elevators, motors and pumps, and arc welders.

How Can A Blackout Cause A Power Surge?  It is not the loss of power that causes a power surge and equipment loss. The damage occurs when electricity resumes, sending a sudden surge of power through the lines.

What Can You Do To Protect Equipment?  Install properly grounded surge suppression devices where the utility power comes into the building, at circuit breakers and for pieces of equipment. If possible, unplug equipment when you expect a storm or power disruption.

There’s A Lot On The Line.  Too many people make the mistake of only installing surge protection on electrical lines. Surges also can enter on telephone and fax lines, cable or satellite systems, local area networks, even plumbing. Protect all pathways.

The Lowdown On Lightning.  People often discuss lightning and voltage surges as two distinct phenomena, when lightning is just one type of surge.

What Causes Lightning?  In the simplest terms, lightning is an electrical discharge between positive and negative regions of a thunderstorm. Although cloud-to-ground strikes are the most damaging and dangerous, lightning can also discharge within clouds and from cloud to cloud.

Static Electricity.  Another form of environmental surge is common electrostatic discharge, which can be especially damaging to sensitive electronic equipment. You and your equipment should be grounded before opening up computers or working with circuit boards or controls.