To use a power strip and surge protector safely, you need to understand the difference between the two items.

“Very often power strips and surge (protectors) are mistaken for each other,” says Underwriter Laboratories’ consumer safety director John Drengenberg, an electrical engineer with decades of experience. “A power strip extension cord is nothing more than a short extension cord with a lot of outlets on it.”

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    Some power strips have built-in surge protection and some come with a circuit breaker that shuts off the power strip if it’s overpowered by too many connected devices. But a power strip without these added features offers no protection from a current spike jolting down the power line.

    Surge protectors (sometimes sold as “surge suppressors”) are different. They contain circuitry that will shut down if the flowing current exceeds a certain level. This helps prevent a power surge that could fry your pricey laptop, smartphone or flat-panel TV.

    Rural areas and regions prone to lightning are more susceptible to power surges. Even so, you don’t need surge protection on every power outlet. “Your toaster probably won’t be affected,” by a power surge, says Drengenberg. But if you’re connecting electronics to a power outlet, use a surge protector. The big problem even with a small power surge, he says, is data loss on computers.

    How to shop for a surge protector

    Underwriter Laboratories tests and rates the safety of surge protectors. Products that pass muster display a UL approval label. Shop for a surge protector with a “UL 1449” label that shows it is listed as a surge protector device and isn’t just a power strip extension cord. UL also uses holographic labels on approved surge protectors to prevent counterfeiting on cheap and typically imported surge protectors, Drengenberg says.

    Surge protectors are measured in joules or resistance. You can almost always find the surge protector joules on the packaging; the more joules, the better the surge protector. When shopping for a surge protector, look for the suppressed voltage rating.

    “You can get them in a range from 330 volts up to 4,000 volts,” Drengenberg says.

    The lower the voltage rating, the faster the surge protector will activate. For home electronics, you want a surge protector on the lower range of the voltage scale, so the device will shut off before a power surge can fry the equipment connected to it.

    Like anything else, surge protectors will wear out. Replace a surge protector if it’s been tripped by a power spike since that may have ruined the component. A surge protector is like a bicycle helmet in the sense that it’s designed to handle one crash – after that, you should get a new one.

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    Preventing power surges

    A thunderstorm with lightning over a town.

    There are two ways you can protect against a power surge, according to the Energy Education Council:

    1. Have an electrician install a protector to the main circuit box in your home.
    2. Use consumer-grade surge protectors to connect in-between the wall outlet and electronics.

    Power surges don’t just come from lightning strikes or irregular delivery from the electric company. Big appliances such as freezers and AC units can trigger a power surge on home wiring. And because power surges can also come in through home landlines and coaxial cable for television service, you may want to buy a surge suppressor with connections for these lines as well.

    Electrical safety tips for the holidays.

    Be cautious when using power strips

    “Power strips are merely a convenience,” Drengenberg says. “They don’t offer any real protection from a power surge.” But if you’re using them to plug in smaller appliances – such as hair dryers and lamps – which are less likely to be damaged in a power surge than electronics, you may not need the extra protection provided by a surge protector.

    If you do decide to use a power strip extension cord, keep in mind it has a rating on how much power it can draw. You need to look at the device you’re plugging into the power strip and make sure it’s not going to overheat because it draws too much power.

    When connecting multiple appliances to a power strip, check the wattage on each appliance and be certain the total of all connected appliances does not exceed the rating of the power strip. Otherwise, overheating could result in a fire.

    Power is measured in wattage, which can make choosing a power strip confusing. That’s because appliances are often listed by wattage – amps multiplied by volts. Since most people are accustomed to 120-volt power outlets, watts might mean very little. But to buy the right protection, a little math may be helpful.

    To determine the number of amps, you’d divide the wattage listed on the appliance by the household circuit voltage. So an appliance rated at 1,200 watts divided by 120 volts (standard household electrical supply) would be equivalent to 10 amps.

    A rack of computers with multiple plugs.

    Do you have an extension cord fire hazard?

    Appliance Surge Protector

    There is a difference between a normal surge protector and an appliance surge protector. If you’re protecting a large household appliance, like a refrigerator, normal surge protectors likely won’t be able to absorb enough Joules to prevent damage to your system. Appliances use a lot more current than other electronics you normally see around the home so it’s important to know the difference. For large appliances like washers and dryers you will probably want a surge protector that can absorb at least 600 – 900 Joules to be safe.

    For the math-averse, Drengenberg has a suggestion. “Just to be safe,” he says, “talk to the hardware store people before you buy.”

    Steve Evans is an award-winning journalist with more than 20 years’ experience in daily news and business journalism. Among other jobs, he has served as managing editor of the Central Virginia Newspaper Group, as a staff writer for the Richmond Times-Dispatch and as a senior writer for SNL Financial and a reporter for He has written widely about consumer finance topics.