

Use grounded (three-prong) or polarized (one blade thicker than the other) plugs whenever possible.Bypassing the ground negates most of the benefits of using surge protectors, since typically two-thirds of their MOVs are tied to the ground leg. Never use an adapter to plug a surge protector into an ungrounded outlet.The worst-case scenario is that something starts melting-that’s the opening act for an electrical fire. The best-case scenario is that you trip a breaker or blow a fuse. This is an easy way to exceed the current ratings on the surge protector and even the wiring in your walls.

Never daisy-chain multiple surge protectors to add outlets, and never plug a surge protector into an extension cord.Attractive, slim design was a plus, and we considered well-designed clamps, hooks, or holes for mounting the surge protector on a table or baseboard to be a bonus. Sensible port layout and overall design: To keep oversize plugs from blocking nearby outlets, we looked for adequately spaced ports.Long power cord: If a surge protector has a power cord, longer is better because it’ll be safer and more convenient to use.However, a warranty covers only defects and won’t help you when the surge-absorbing components wear out as designed. At least a one-year warranty: This is a bare-minimum requirement for something that you’re trusting to protect high-priced equipment and that you’ll be replacing every few years.USB ports are handy for charging a phone or other small device without a wall charger, but since most won’t charge a phone at top speed, we don’t think they add much value. Convenient auxiliary ports: We preferred models with coaxial connectors, which are commonly used in AV devices, as well as telephone ports for a landline phone or dial-up internet connection.But since this is just an estimate, we didn’t put a lot of stock in it. High joule rating: A joule rating tells you about how much energy the surge protector can absorb before it fails, so higher is better.Lower is better when it comes to let-through voltage, the measure of how much extra voltage reaches your electronics. A surge-protection rating of 400 volts or better: Although we verified each model’s abilities in our own electrical testing, we required that they be rated by one of the major product-safety corporations, UL or ETL, to bring a surge down to (at most) 400 volts.At least eight AC outlets: We required at least eight AC outlets for the main and top-of-the-line contenders, and at least three for our light-duty pick.

Otherwise, at minimum, we required each model to have an indicator light that signals when its surge-protection capabilities have worn out.
