Whole Home Surge Protection: What It Does and Whether You Need It

What causes power surges

A power surge is a sudden spike in electrical voltage that lasts a fraction of a second — long enough to damage electronics, degrade appliances, and in some cases start an electrical fire.

Surges come from two directions.

External surges

Come from outside your home. Lightning is the most obvious cause, but most external surges come from the utility grid — switching events, downed lines, equipment failure, or power restoring after an outage. You have no control over any of these.

Internal surges

Come from inside your home. When a large motor-driven appliance — a refrigerator compressor, an air conditioner, a furnace blower — cycles on and off, it creates small voltage spikes. These aren't dramatic, but they happen dozens of times a day and contribute to the gradual degradation of electronics over time.

What whole home surge protection does

A whole home surge protector is installed at your electrical panel. When a surge enters from outside the home — or originates from within — the device diverts the excess voltage away from your circuits before it reaches your wiring, appliances, and devices.

This is different from a power strip surge protector in one important way: a whole home device protects every circuit in the house, including hardwired appliances like your furnace, air conditioner, refrigerator, and dishwasher that can't be plugged into a power strip at all.

What it does not cover

A direct lightning strike to your home is an extreme event that can exceed the capacity of any surge protection device. Whole home protection significantly reduces the risk and damage from most surge events — including nearby lightning strikes — but is not a guarantee against all damage in a worst-case direct strike. Harrison Electric will always be straight with you about what any product does and doesn't do.