Engadget: Surge Protectors Need Periodic Replacement as Protection Degrades

The wear is not obvious. Engadget said a surge protector may successfully blunt two or three surges and still look like an ordinary power strip. Depending on the design, it can keep supplying power after its MOV components no longer work properly. Some models shut off outlets when the protection mechanism fails, according to the report.

Engadget noted that some surge protectors use TVS diodes, silicon avalanche diodes or gas discharge tubes, but MOVs are by far the most common in households. The report advised users first to determine whether they have a surge protector or merely a power strip, since the two look nearly identical. A surge protector usually has an indicator labeled Protected or Protection Present. Users should consult the instructions for their specific model because the meaning of the light varies. On some units, an unlit protection indicator means the surge-suppression components have failed.

If the instructions say the light indicates protection has failed, the surge protector should be discarded and replaced. Engadget also said a surge protector should be thrown out if it is smoking, has scorch marks, or shows melting plastic. After a lightning strike severe enough to knock squirrels from trees and send a housecat scrambling, the report said, the surge protector should be replaced once the storm clears.

The article warned against plugging space heaters and similar high-load devices into surge protector strips. Such a load can overheat the strip or make it degrade much faster than normal.

On timing, Engadget said a five-year deadline is not necessarily a good rule for every surge protector. How long one lasts depends on its design and the number or size of surges it has handled. Some manufacturers suggest considering replacement every three to five years, especially because users rarely keep count of surges. But the report said that is only a suggestion, not a guarantee that even a premium surge protector will last five years.

If the age of a strip is unknown and there is no way to tell whether it still provides protection, Engadget said replacing it is the smartest option. When a surge protector is replaced, users should look for clear protection status indicators and write down the purchase date somewhere practical. The report added that a surge protector is not an all-out lightning shield and that no standard surge protection device can handle a direct lightning strike.

Engadget said surge protectors differ in how they signal failure. Some use lights, while others trip a switch similar to a breaker box, and some lights have different meanings. The best approach, according to the report, is to learn how the purchased device functions and replace it when the instructions say so. Users should not assume it will last five years, particularly in areas where afternoon thunderstorms are common.

Editor's Summary

Engadget reported that surge protectors can lose protection as MOV components degrade, often without visible warning, and may continue powering devices after protection fails. It advised checking protection indicators, replacing units after failure signs or lightning strikes, avoiding high-load devices such as space heaters, and not treating any standard surge protector as a direct lightning shield. The report said replacement schedules depend on design and surge history, and that a three-to-five-year window is only a manufacturer suggestion.