Electrical power surges are a danger to your home and your possessions. Today, many appliances are controlled by electronic control circuits. These are especially susceptible to damage from electrical power surges. In the extreme cases, a major power surge can even cause a fire.
The most common cause of a major electrical power surge is a lightning strike. When lightning strikes on or near your home, it is seeking a way to ground. It will travel through all connected wires until it finds a ground, which is often your computer or other appliance. A power surge from lightning is very powerful and few appliances are made to withstand such power.
Another cause is a fault in the transmission lines from your electric provider. While generally not as strong as a lightning caused surge, it is still enough to kill your delicate electronic equipment or destroy data on your computer. Developing countries are particularly likely places to find these types of surges, but they can be from anywhere.
Static electricity generated inside your house, especially on very dry days, is another source. Scraping your feet on the carpet and then touching the appliance can be enough to cause damage. Sometimes older major appliances, such as refrigerators or air conditioners, generate a strong surge when their compressors are cycled in.
Individual surge protectors are required in most areas by the local code, but are mandatory usually only for areas in the house that are near water, such as sinks. This is why it’s a good idea to look into whole house surge protector systems. They are not as easy to find, and they should be professionally installed, but it’s worth the effort to protect your entire home.