Do Surge Protectors Wear Out?

Surge protectors, or surge suppressors, are used everywhere. They are in homes, offices, workshops and even on construction sites. Just like basic power strips, surge protectors have several outlets, which allows you to conveniently plug in multiple items. However, surge protectors go beyond this basic function because they are designed to protect electronics from damaging surges in electricity. Fortunately, they are relatively inexpensive (compared to the valuable equipment they protect) so there's really no excuse not to use them. But you can't just plug everything in to a surge protector and forget about it. Over time the device will lose it's protective capabilities and you'll need to replace it.

But how do you know when your surge protector has degraded to the point where it's a simple power strip, no longer protecting anything? Read on.

Surge protectors are rated in joules, which indicate how much protection the unit is designed to provide. For example, you might have a 500 joule (500J) surge suppressor. The 500J spec is a measure of the total amount of energy the device can absorb before the protection wears out. Once that happens the unit can't absorb any extra voltage or surge.

So, the older your surge protector is, the more likely it’s degraded. (Quick tip: if you can't remember when you bought it, get a new one.) However, it's not that simple because a surge protector's lifespan isn't measured in years — it's measured in those joules mentioned above. Obviously, the higher the number of joules, the greater the amount of available protection when the unit is new and unused. The critical factor here is that every power surge your surge protector absorbs decreases the amount of joules available for future surges. For example, if a surge suppressor rated a 500J takes a 500 joule hit, it’s toast. Likewise, over time, the same result will occur if it receives five 100 joule hits — or if it gets five hundred 1 joule hits. It adds up in a cumulative effect.

So how do you know when your surge protector has lost it's ability to protect your equipment and become a basic power strip? Unfortunately, you can't know for sure if your chariot has turned into a pumpkin. Bad Ass surge protectors have warning lights designed to alert you to the loss of protection. However, in the real world, if the unit is old, it's risky to rely on the lights. It's better to err on the side of caution and replace the unit. If you know your surge protector took a big hit during a recent storm or similar event you should probably toss it too. Otherwise, as a rule of thumb, is a good practice to replace surge protectors every two years or so.