Source: The National Electrical Manufacturers Association (NEMA)
According to the National Electrical Manufacturers Association, an “electrical surge is a sudden and unwanted increase in voltage that can damage, degrade, or destroy sensitive electronic equipment in a home or business.”
Two main sources of electrical surges are lightning surges and overvoltage generated by the equipment. Lighting surges are the most familiar source for electrical surges; however, they are one of the least common causes. NEMA states, “When lightning strikes near a power line, the electrical energy can boost electrical pressure by millions of volts.”
NEMA estimates that 60% to 80% of surges are created within a facility, such as when large appliances (e.g., air conditioners) turn on and off. This switching creates sudden, brief demands for power, which upset the steady voltage flow in the electrical system and causes repetitive surges. While these surges are nowhere near the intensity of a lightning surge, they can be severe enough to damage components, immediately or gradually, and they occur regularly in most building’s electrical systems.