How Surge Protectors Work

By: Tom Harris & Talon Homer  | 

Surge Protection Levels

All surge protectors are not created equal. In fact, there is a tremendous range in both performance and price of protection systems.

  • At one end, you have your basic $5 surge protector power strip, which will offer very little protection.
  • On the other end you have systems costing hundreds or even thousands of dollars, which will protect against pretty much everything short of lightning striking nearby.

Most systems have limitations of some sort; picking out a protector system that suits you is a matter of balancing the cost of the system with the cost of losing data or electronic equipment. As with insurance, you find the level of coverage you're comfortable with.


To protect your equipment from surges, you need individual surge protectors for each outlet. These power strips range a great deal in quality and capacity (as we'll see in the next section). There are three basic levels of power strip surge protectors:

  • Basic power strip: These are basic extension cord units with five or six outlets. Generally, these models provide only basic protection.
  • Better power strip: For $15 to $25 you can get a power strip surge protector with better ratings and extra features.
  • Surge station: These large surge protectors fit under your computer or on the floor. They offer superior voltage protection and advanced line conditioning. Most models also have a USB outlet, and may feature built-in circuit breakers. You can get one of these units for as little as $30, or you can spend upward of $100 for a more advanced model.
  • Uninterruptible Power Supply (UPS): Some units combine surge protection with a continuous UPS. The basic design of a continuous UPS is to convert AC power to DC power and store it on a battery. The UPS then converts the battery's DC power back to AC power and runs it to the AC outlets for your electronics. If the power goes out, your computer will continue to run, feeding off the stored battery power. This will give you a few minutes to save your work and shut down your computer. The conversion process also gets rid of most of the line noise coming from the AC outlet. These units tend to cost $150 or more.

Be aware that some cheap power strips will be labeled as a "relocatable power tap," rather than surge protectors. These devices are simply made to split one 120 volt outlet into multiple power sources, but won't provide any additional defense in the event of a power surge. These can look almost identical to surge protectors, so make sure the packaging clearly states the product's features before purchasing.

An ordinary UPS will give you a high level of protection, but you should still use a surge protector. A UPS will stop most surges from reaching your computer, but it will probably suffer severe damage itself. It's a good idea to use a basic surge protector, if just to save your UPS.

Once you've decided what level of surge protection you need, it's time to shop around for a good unit. In the next section, we'll find out what you should look for when considering different models.