Surge Protectors

Category: Hardware

I'm looking for a surge protector for my computer equipment and I'm wondering if those power strip models with built-in surge protection are any good. What should I look for when trying to protect my computer from lightning strikes?

Surge Protectors

Do I Need a Surge Protector?

A few years ago, after a lightning strike, I examined my lifeless motherboard and found that it had a big scorched area on it. I've also had to replace modems and power supplies that have taken a hit during an electrical storm. So the short answer is YES... you do need a surge protector.

Lightning doesn't even have to hit your house for your computer to die of electrocution. "Electrical events" sufficient to do the can happen many at any time in the average home or office. If you do not protect your computer from such events, you're taking a risk as great as motorcycling without a helmet. The first and most frequently used line of defense is the surge protector. It won't protect you 100%, but a surge protector is cheap insurance and I recommend them for everyone.

The voltage on normal power lines fluctuates up and down all the time, like waves lapping up and down against a dock or river bank. If the voltage rises too high it can burn out delicate electrical circuits in your computer. If it falls too low you get things like hard disk head crashes which can scratch the surface of a hard drive and render it virtually unreadable. Exceptionally low voltage drops are called brownouts. Exceptionally high voltage spikes are called power surges.

Surge protectors protect only against power surges, not brownouts. To maintain sufficient power when it drops on the line you need a backup power supply called an Uninterruptible Power Supply (UPS). Even small capacity UPSes cost at least $50, but surge protectors come in a wider and lower range of prices. You should choose the best you can afford.

Surge Protector Features to Look For

"Clamping voltage" is a key feature to look at in a surge protector. It is the voltage level at which the protector's circuitry will "clamp down" on a surge to suppress it. A clamping voltage of about 330 volts is good for most home and office computers.

The joule rating indicates the amount of electrical energy that a surge protector can absorb before burning out. The bigger the surge and the more frequently surges occur, the sooner a protector of a given joule rating will need to be replaced. A $10 surge protector rated at 200-300 joules probably won't give you much protection. I suggest you look for one that's rated at 600-1000 joules. Buy the highest joule rating you justify, given your budget.

An expensive "whole-house" surge protector plugs in where the main power line enters your home or office, dampening surges on every line throughout the protected space. But it only dampens surges that are in the power as it enters the premises. Surges can also arise within the space's network of wiring, past the surge protector. A whole-house surge protector won't do anything about those. Generally, the best protection is offered by a point-of-use surge protector which plugs into the electrical outlet and into which you directly plug your computer.

A three-line surge protector protects the positive, negative, and ground wires in three-wire plugs, providing complete protection. Surges can come up the ground wire from Mother Earth, especially during electrical storms.

A phone jack is a good idea on a surge protector if you connect a phone line to your computer for faxing or dialup networking. One cable goes into the wall jack and plugs into the surge protector, while a second cable connects the surge protector's phone jack to your computer's phone jack. Similarly, you might want a network (ethernet) jack on your surge protector, since it's yet another pathway for a volt jolt to enter your computer.

Surge protectors come in a variety of configurations, from single- and dual-outlet models to six- or eight-outlet ones that increase the number of devices you can plug into a two-outlet wall outlet. There are models that simply plug into a wall outlet and snuggle right over it, and power strips that give you more space between cords and an extra length of cord to put power where you need it.

Surge protectors do eventually wear out from absorbing power surges, so a "replace me" indicator light or audible signal is a good option. To be even safer, if you know you've been hit with a very severe surge, it's a good idea to replace all your surge protectors.

Which Surge Protector Should I Buy?

Of course, the best surge protection is to unplug your electronics when your equipment is in danger, such as a lighting storm. The storm can be quite far away and still create a surge that travels on the power lines. If you hear thunder, it's wise to unplug. But I still recommend a good surge protector, because storms can hit when you asleep or away from home.

Just a few brand-name makers of quality surge protectors include Belkin, APC (American Power Conversion), and Tripp Lite. Research a maker's reputation before buying, and avoid very low-cost no-name surge protectors whose circuitry and energy-absorbing components may be shoddy.

Read any warranties and guarantees that are offered. Some companies offer to repair or replace any equipment damaged by a surge or spike while connected to their surge protector. If the manufacturer is willing to do something that will cost them money, chances are they've designed their product well enough to minimize that risk.

Got something to say about surge protectors? Post your comment or question below...

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Most recent comments on "Surge Protectors"

Posted by:

Frank Woodman Jr
11 Oct 2009

Surge protectors are on area of protection that most over look or try to fix "on the cheap". As you state the cheap "no name" protectors offer little or no protection. So stay with the name brands and look for the best numbers. Of course if you really want the best and ultimate protection use the Brick Wall line of products. They use a completely different system than the standardized MOV's that most protectors use. If you want the best check out the details here on their web site at and get the facts. It's still informative and interesting reading even if you don't choose to use their product. It takes the facts to make informed decisions.

Posted by:

11 Oct 2009

Bob, I have used an APC surge protector plus battery back-up system for several years and am very pleased with this company. It just makes sense to me to have a battery back-up along with the surge protection. When the power goes off, my system does not, and I have the time to shut the system off properly.

Posted by:

hannington opondo
12 Oct 2009

i own Sony vaio laptop the problem is that i have always replaced my wall charger more than 4 times till now i want to use dell charger since my friends who own dell and work at same place their don't get burned mine have always.

please advise.

Hannington opondo

Posted by:

12 Oct 2009

What about products that use external transformers (like most printers, modems, etc)? do they need surge protection as much as, say a computer?

Posted by:

13 Oct 2009

I did have a surge protector hooked up to my computer, but a few months ago some kids were playing chase down main street and hit a power pole which caused a power surge and my computer/harddrive got totally fried. I was told at that time by many savy computer people that a battery backup surge protector is the only and best way to go to really protect your computer from any future power surge type problems. Luckily my computer was still on warranty so I didn't have to pay too much through the nose to get it back up and running, but lost a lot of good stuff off my harddrive. Any comments or confirmations on battery backup surge protectors??? I'm not taking any more chances!

Posted by:

Bill Van Skiver
13 Oct 2009

Hi Bob,
Good article on surge protectors. One that you, as well as the readers should check out on surge protectors is I bought one, from them about6 years ago and have been happy with it. This is NOT your run-of-the-mill protector! There is a complete history of the founder of the company which you should find interesting. These units are heavy but about 4"X4" square and about 7" high. They carry a 10 year warranty. The CEO of the company says that this warranty is conservative, as you should expect it to last for a lifetime, given the quality of the components in it. It's absolutely nothing like the regular MOV protectors. They're not cheap, but in this case, you WILL get what you pay for! Check 'em out!

Posted by:

Jason Wallwork
24 Oct 2009


External transformers don't have any protection against surges. Any equipment you care about and that is connected to anything you care about, should be plugged into a surge protector.

The big thing I see all the time is people plugging their laptops into power outlets with no protection. Not a good idea.

Posted by:

24 Oct 2009

And don't forget other appliances around the home. A severe lightning storm fried the main circuit board in our 3 week old Maytag washing machine. They repaired it under warranty, but the service man suggested a GOOD surge protector to protect it when the warranty runs out. We also lost an answering machine in the same storm.

Posted by:

Bruce Fraser
29 Oct 2009

A new product on the market: a surge protector, but also an energy saver. They're called "Smart Power Strips." When the device (such as your computer or TV) plugged into the "control outlet" is turned off, then all peripherals plugged in to the strip are also turned off.

Posted by:

lily chi
25 Mar 2010

Surge protector is necessary for equipment.It is good for power protection. MOV cannot be used as the key components in a surge protector, it is easy to burnt when lightning happened.You should choose ceramic arrester. Some surge device use both MOV and ceramic arrester as the main parts in a surge protector. Most shop import these surge protectors from China. If you are interested in this, welcome to contact me:, or visit our website:

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