Power surges occur when the flow of electricity is interrupted, then started again, or when something sends electricity flowing back into the system.
Surges can range from five or ten volts when you turn on your hair dryer to thousands of volts if lightning strikes a transformer.
Internal power surges
More than half of household power surges are internal. These happen dozens of times of day, usually when devices with motors start up or shut off, diverting electricity to and from other appliances.
Refrigerators and air conditioners are the biggest culprits, but smaller devices like hair dryers and power tools can also cause problems.
External power surges
An external power surge, stemming from outside your home, is most commonly caused by a tree limb touching a power line, lightning striking utility equipment or a small animal getting into a transformer.
Surges can also occur when the power comes back on after an outage, and can even come into your home through telephone and cable TV lines. |
