• On TechRepublic: 10 most annoying default configurations
September 10, 2007 2:33 PM PDT

What makes a good surge protector--Part 1

by Michael Horowitz

Everyone knows to use a surge protector for their computer. But which one? How do you choose? Welcome to surge protector school.

As their name implies, surge protectors prevent voltage spikes from entering a computer (or whatever else is plugged into them). They are available in a variety of types and, to paraphrase the manual that came with a Dell server, usually provide a level of protection commensurate with the cost of the device. In other words, you get what you pay for.

A surge protector is not a power strip, although a low end model may look like a power strip. Power strips are just extension cords and won't protect a computer from power surges. If it doesn't say "Surge Suppressor," it is probably just a power strip. You can also judge by the price, power strips are cheaper than surge suppressors. A device with no Joules rating is a power strip.

There are many features that go into making a good surge protector.

To begin with, electrical surges can happen on any wire. Thus, you need a surge protector that protects every wire going into your computer. This includes the phone line, if you use dial-up or DSL, and Ethernet network cables, if the computer is on a LAN. Lower end surge protectors only protect the electrical outlet; to get Ethernet or phone line protection, expect to pay a bit more. As a starting point, expect to pay from $20 to $35 for a surge protector.

Have you ever blown a fuse? Some surge protectors work like fuses, and when they absorb all the electricity they can, they die. They may die either from a single big surge or from absorbing many small surges over a long period of time.

What then?

Most likely, a dead surge protector will indicate the fact that it is no longer protecting your equipment with some type of indicator light. However, months after installing it, will you know what the light means? You may not even see it, if the surge protector is behind furniture.

When the surge suppression no longer functions, some surge protectors will continue to provide electricity to the devices. Better models cut off the juice, which protects your devices and makes sure you know to replace the surge protector. Never use a surge protector that provides unprotected power! The last time I checked, the current models of both APC and Tripp Lite would never provide unprotected power to your devices.

You may be thinking that fuses have been replaced by circuit breakers. When there is an overload, a circuit breaker trips and you can easily switch it back later without having to go to the hardware store and buy a new fuse.

Better surge protectors work this way, too. These models are designed to cut off power in a surge rather than absorb it. As a result, they should not wear out over time. There will be a little button that pops out, and you can pop it back in after the surge.

How can you tell if a particular surge protector works like a fuse or circuit breaker? One hint is the warranty, if it has a lifetime warranty then it probably works like a circuit breaker. I suggest only purchasing a surge protector with a lifetime warranty. In general, both APC and Tripp Lite surge protectors have lifetime warranties.

Next up, clamping speed and let-through voltage.

Michael Horowitz is an independent computer consultant and the author of several classes on Defensive Computing. He is a member of the CNET Blog Network, and is not an employee of CNET. Disclosure.
Recent posts from Defensive Computing
Fixing bugs in the Flash Player yet again
Getting more battery power for your computer
Get an MSI Wind Netbook for only $349
Not interested in a Netbook computer? Consider the Honda Fit
Beware emails linking to blogspot.com
When Word documents break
More about printer ink rip-offs
Some computers are too important to be networked
Add a Comment (Log in or register) (9 Comments)
  • prev
  • 1
  • next
More Surge Defeating Devices Info
by tenc21 September 11, 2007 11:46 PM PDT
Michael, you omitted mention of the ultimate protection against powerful ligthning strikes--always unplug the surge protector when not in use!
(http://whatis.techtarget.com/definition/0,,sid9_gci213630,00.html)


A comparison of suppressors is found here:
(http://www.askthebuilder.com/B235_Surge_Protector_Suppressor_Protection_Guide.shtml) Curiously, Tripp Lite is not listed.
Reply to this comment
More Surge Defeating Devices Info
by tenc21 September 11, 2007 11:46 PM PDT
Michael, you omitted mention of the ultimate protection against powerful ligthning strikes--always unplug the surge protector when not in use!
(http://whatis.techtarget.com/definition/0,,sid9_gci213630,00.html)


A comparison of suppressors is found here:
(http://www.askthebuilder.com/B235_Surge_Protector_Suppressor_Protection_Guide.shtml) Curiously, Tripp Lite is not listed.
Reply to this comment
surge protector internal batteries
by raisabark September 14, 2007 3:33 PM PDT
Is it true that every surge protector's internal battery has a limited life - about three years?
Reply to this comment
No batteries in a surge protector
by mhinnewyork September 15, 2007 11:00 PM PDT
Surge protectors don't have batteries. You're probably thinking of a UPS - Uninterruptible Power Supply.
surge protector internal batteries
by raisabark September 14, 2007 3:33 PM PDT
Is it true that every surge protector's internal battery has a limited life - about three years?
Reply to this comment
No batteries in a surge protector
by mhinnewyork September 15, 2007 11:00 PM PDT
Surge protectors don't have batteries. You're probably thinking of a UPS - Uninterruptible Power Supply.
by bill.8992 December 31, 2007 4:19 AM PST
Can you connect surge protectors in series and increase the joule level of protection?
Reply to this comment
by stalbanswva3 June 18, 2008 7:36 PM PDT
Reply to this comment
by Haalelea April 8, 2009 1:00 PM PDT
I would like to get a surge protector for my refrigerator, to save its circuit boards in case of any surges. What is recommended?
Reply to this comment
(9 Comments)
  • prev
  • 1
  • next
advertisement
Click Here

Making sense of Windows 7 upgrades

faq The basics and the fine print on Microsoft's options for those eyeing the next operating system from Redmond.
• Full Windows 7 coverage

Road Trip 2009: Big Sky Country

CNET News reporter Daniel Terdiman takes his car full of gadgets to the Rockies and the Great Plains in search of tech, science, nature, and more.
• America's Fortress: Cheyenne Mountain

About Defensive Computing

Michael Horowitz is an independent computer consultant and the author of several classes on Defensive Computing. He views Defensive Computing as taking steps, when things are running well, to avoid or minimize the inevitable problems down the road. It's about educating yourself to the level where you can make your own intelligent decisions about keeping your computers and data happy and healthy. If you depend on computers, yet are on your own, without an IT department or nearby nerd, this blog's for you. His personal web site is michaelhorowitz.com.

He is a member of the CNET Blog Network and is not an employee of CNET.

Disclosure.

Add this feed to your online news reader

Defensive Computing topics

advertisement
advertisement

Inside CNET News

Scroll Left Scroll Right