How to choose a surge protector
Find out why many surge protectors don't protect your equipment.
Your computer works on electrical power. This power usually flows evenly without interference. But during a rainstorm, lightning may cause surges to the power supply in your home.
Most are easily caught by the circuit breakers and no harm is caused, but you can get a surge that the circuit breakers don't catch because they are below the threshold limit. This is what you have to watch out for when choosing a surge protector.
Why do I need power protection, anyway?
The more money you invest in your television, DVD player, home theater entertainment centers, computers or other electronics, the higher the stakes. If you have had the experience of a thunderstorm, you know that your electronics are vulnerable to power spikes and surges. You may know someone who has lost a TV or computer to a power surge.
Preventing that kind of damage is what power protection does. After all, unplugging your TV during a storm may not be enough. If your cable box or satellite receivers remain connected you've left a 'back door' open for that lightning strike.
The other kind of power loss, 'a brown out' is done to an audio/video system by these minor fluctuations in power. Electromagnetic interference and radio frequency interference can also impair your system's performance.
Be Careful with Cheap Power Strips
Inexpensive power strips normally just break the connection if too much power comes through the line. And even there, cheap strips can fall down on the job.
General purpose power strips have higher tolerances than expensive audio/video equipment so a surge that could damage your components could pass through the strip and still be under the voltage required to trip the circuit breaker. A surge protector that doesn't protect against surges is not much good.
Keep in mind that a surge protector is not a multi-socket power strip. Although many think it is. They confuse an extension cord with a real surge protector. A point-of-use surge protector guards individual devices from lower-level internal fluctuations. If you are looking for a surge protector, here's what to look for:
- Enough connections to protect all components of a system
- An on/off switch allowing you to shut off power to every component
- An indicator light or audible alarm so you know a high-level surge has occurred
The Underwriter's Laboratory Rating
The Underwriters Laboratory rating is also important. A UL-1449 rating ensures that adequate testing was conducted. In other words, is this device good because the manufacture says it is or because it complies with independent testing? The UL rating says that it was tested to independent testing criteria. Additionally, there are other important features:
- The level at which the device begins to block the surge is the clamping voltage. A clamping voltage of 330 is good but you would like to have a lower clamping voltage.
- The surge protector should be able to dissipate the total energy coming across; the higher the dissipation, the better.
- The measure of the ability to absorb surges is the joule; a rating of 400 is good but 600 is better.
- You want a clamp down response time of 10 nanoseconds or less.
- You want protection between all three wire combinations: L - G, N - G, L - N.
- You also want a warranty against damage to any connected equipment. But keep in mind that no surge protector will be fully warranted against lightning strikes.
- Filters for line noise, also known as electromagnetic interference, should be available.
And as a practical matter, even if you get a good surge protector and you are in the middle of a big electrical storm, turn off and unplug your electrical devices - especially your computer.
It is important, when choosing a surge protector that you look at protection, not price. After all, your devices are there for their functionality.