How Surge Protectors Work

By: Tom Harris & Talon Homer  | 

When to Use a Surge Protector

surge protector
You'll want to use a surge protector when you plug in electronics like computers, entertainment center equipment or high-end gaming consoles. Perry Mastrovito/Getty Images

In the last section, we saw that power surges are regular occurrences that are unavoidable in our current electrical system. This raises an interesting question: If we have to expect power surges, why didn't we need surge protectors in our homes 50 years ago?

The answer is that a lot of the components in sophisticated modern electronic devices (such as computers, game consoles and high-def TVs) are much smaller and more delicate than components in older machines, and are therefore more sensitive to current increases. Microprocessors, which are an integral part of all computers as well as many home appliances, are particularly sensitive to surges. They only function properly when they receive stable current at the right voltage.


So whether you should get a surge protector depends on what sort of device you're hooking up to the power supply.

  • You should use a surge protector with your computer. It is filled with voltage-sensitive components that a power surge could damage very easily. At the least, this damage will shorten the life of your computer, and it could wipe out all your data or destroy your system.
  • It's a good idea to use surge protectors for other high-end electronic equipment, such as entertainment center components. A surge protector will generally extend the life of these devices, and there's always a chance that a big power surge will cause severe damage.
  • It's best not to plug devices that naturally draw high amounts of amperage into a surge protector, as they can cause excessive wear on the protector during use. These include devices with heating elements or large electric motors, such as coffee makers, space heaters, fridges or vacuum cleaners. These appliances should be plugged directly into a wall outlet.
  • Do not chain multiple power strips together, as this can cause incorrect voltage output, overheating and even fire.

One problem with surge protectors is that the MOVs can burn out with one good surge. Therefore it's good to get a protector with an indicator light that tells you whether or not it's functioning properly.

Even if you connect surge protectors to all your outlets, your equipment might be exposed to damaging surges from other sources. Any lines carrying signals into your home can also carry a power surge, due to lightning or a number of other factors. If you have a coaxial cable line hooked up to expensive equipment, consider a cable surge protector. Surges on these lines can do just as much damage as surges over power lines.