The Value

The Value of Whole-House Surge Protection

A power surge happens in milliseconds — a thousandth of the time it takes you to blink your eyes. Maybe you see the lights flicker, or your computer locks up for no apparent reason. Maybe you don’t notice anything at all.

But that little spike in the current flowing through the wires of your house can have big consequences. The Insurance Information Institute includes insurance claims from power surges in the same category as damage from lightning strikes. Together they resulted in more than USD1 billion in insured losses in 2008, with an average claim of USD4,329. There’s an easy and affordable way to steer clear of those kinds of losses. They’re called whole-house surge protectors, and here’s how they work.

What causes power surges

Most people worry about a power surge being caused by something outside of the house, like a lightning strike or a downed power line. While lightning is the most dangerous cause of surges, it’s far from the most common. According to the NEMA Surge Protection Institute, 60% to 80% of power surges start inside the home known as internal transient, typically from major appliances and systems that cycle on and off, such as air conditioners, refrigerators, water pumps and clothes dryers. It can happen all day long as evidence when we place a surge counter to record the surge activities.

Over time, those fluctuations take a cumulative toll on sensitive electronics, such as plasma, LED TVs, computer equipment, microwaves, air conditioners and smart appliances, causing delicate circuits to malfunction or burn out prematurely.

Whole-house surge protection

A whole-house SPD can protect against up to 60,000 amps (60kA) of current flowing into your home from the outside; normal household power is 200 to 300 amps. When a sudden surge occurs, such as from a lightning strike or damage to a power line, the device detects the excess current and safely diverts it through the house’s grounding path.

Make sure any device you buy meets these criteria:

* Rated by Underwriters Laboratories. The standard category is 1449.

* Has a clamping voltage of 400 volts or less. That’s the amount of surge that will trigger the device to divert power from your equipment to the electrical ground. The lower the number the better, says John Drengenberg, consumer safety director for Underwriters Laboratories, which tests the devices.

* Protects all incoming lines. Surges can enter the house through cable and phone lines, too, so if you are using electrical equipment that’s also plugged into a cable or phone jack, such as a fax machine or satellite TV box, make sure the SPD has inputs for all three.

* Has an indicator light. That way you can see at a glance if it has stopped functioning.

No surge-protection device is foolproof; if your house takes a direct hit from lightning, only luck and good karma will keep anything plugged into a power source from being obliterated. But weighed against the damage even everyday power fluctuations can cause, whole-house surge protection is an investment well worth the cost.