Your Complete Guide to Power Surges

updated May 6, 2019
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(Image credit: Apartment Therapy)

Raise your hand if you have your computer plugged in to a surge protecting power strip. OK, now raise your hand if you think that’s adequate to protect your gear in an electrical storm. Wow, a lot of you. The reality is that many of us don’t know enough about power surges. What are they? Where do they start? How can you really protect against them? And what the heck is a whole-house suppressor? We’ve got your answers right here.

(Image credit: Apartment Therapy)

What is a Power Surge?
A power surge happens when there’s an unexpected spike in the voltage supplied through an electrical line. It’s a quick event, sometimes it may last for only a few millionths of a second, but a surge can carry tens of thousands of volts.

What Causes Surges?
Even though you’re on guard whenever there’s a lighting storm nearby, that’s not the most common cause for household power surges. More likely, a surge in your home will be caused by downed power lines, short circuits, tripped circuit breakers, a sudden change in electricity usage by a nearby factory or the transition of an on/off cycle of a large appliance on the same power line (like a refrigerator or laser printer).

But lighting storm surges are still the most powerful, although the lighting has to strike within one mile to cause harm.

What Damage Does a Power Surge Do?
The spike in voltage that comes with a power surge is enough to fry circuit broads, crash hard drives and ruin nearly any device that’s wired in to your grid. A big surge that accompanies a lighting strike could effectively and immediately kill your tech, whether or not it was powered on at the time of the surge. But the smaller, more common surges can also do invisible permanent damage, shortening the life of your electronics.

How Can I Protect my Tech from Surges?
Plugging your devices into surge protection power strips is a good line of defense against small voltage spikes. When a higher-than-normal voltage comes through the wire, the surge protector reacts in milliseconds to divert excess power to the ground wire.

But the really big spikes can damage even your so-called “surge protector,” melting the fuse in your power strip. For large power surges, have a licensed electrician install a whole-house suppressor (It’ll cost about $500 for an average home). The whole-house protector will lessen a power surge to a low enough voltage that your plug-in power strip can handle.

(Images: flickr member D’Arcy Norman licensed for use under Creative Commons, flickr member Samuel L. Livingston licensed for use under Creative Commons)