An electrical power surge is a sudden and short duration spike in the voltage, usually from the electrical grid. These surges can happen anywhere and can be very destructive. External power surges can be caused by lightning or by the your utility when it switches power grids. These surges enter the home through phone lines, cable TV cables or electrical service lines. Power surges can also originate within the home and are caused by large appliances like freezers and air conditioners turning on and off. Most homes experience a fair amount of power surges that are undetectable. It is the more severe power surges that can do damage to appliances within your home.
Because electrical power surges can take several paths, whole house surge protection will involve multiple layers of defense. Ideally, you should think in terms of multiple “layers” of protection: at your power meter, at your distribution panel or fuse box, your phone and cable TV lines and where your individual devices are plugged in.
There are three Surge Protection Devices (SPD’s) that address the multiple layers of defense mentioned above: Type 1, Type 2 and Type 3.
Type 1 SPD’s protect your home from external surges caused by lightning or by utility power grid switching and are installed between the utility pole near your home and your power meter. Installation will require approval from and coordination with your electric utility.
Type 2 SPD’s are located at your circuit panel and help distribute excessive current discharges from external sources (lightning or utility) so as to protect all circuits in your home.
Type 3 SPD’s are “point of use” surge protectors located where individual appliances are plugged in. Sometimes they are referred to as surge strips. These can be an inexpensive and effective solution for your largest and most important appliances.
For those seeking a full line of defense against power surges, it is a good idea to consult with a licensed electrician who can help determine a solution that is best for your home.