The Basics of Surge Protectors


Surge protectors have become a commonplace item in the typical home. The premise is simple: it protects electronic equipment against dangerous spikes in electrical current by diverting extra voltage to a grounding wire inside the unit.

The Whole House

For the average homeowner, there are two types of surges. The first one is a ‘transient overvoltage’, generally caused by circuit switching, cycling, or what we call ‘an electrical event’, say, when someone hits the power line with a ladder, or lightning hits the neighborhood transformer.

A whole house surge protector can hardwired into your service panel to help prevent damage from a transient overvoltage. Sure, it won’t give you six sockets plugged into one electrical outlet in your bedroom, but it will offer whole house protection in the event that the surge comes from outside the house. However, if the surge comes from inside the house (HVAC kicking on or a malfunction) the whole house protector won’t work. For those, you need the outlet-type surge protector.

Individual outlets

Outlet-type surge protectors circumvent surges that happen in your home on a regular basis. These are caused when huge-draw applianced kick on, or other current anomalies.  Even though they aren’t as violent as an electrical event, these surges will wear a surge protector down over time. Keep this in mind, as surge protectors need to be replaced periodically, depending on how much voltage and how often they’re required to divert it.

It should also be said that a surge protector will sacrifice itself in an attempt to protect the electronics it’s been assigned to protect if there is a huge surge

Also, please note that a ‘power strip’ is not a surge protector.

The differences between surge protectors are enormous. How can you tell if it’s actually a decent surge protector? There are three elements which define the quality of surge protection.

The Three Elements of Surge Protector Quality

  1. Response time. Get one with as short of a delay time as possible. (Think nanoseconds.) It doesn’t take long to fry delicate electronics.

  2. The number of joules it will handle. Electrical spikes are measured in joules.

  3. Clamping voltage. Clamping voltage refers to the amount of juice a surge protector will allow before it diverts the current. A lower amount is better, because it doesn’t take much voltage to burn up some electrical items.

Lights indicate if surge protectors are working. Or not working.

Lights indicate if surge protectors are working. Or not working.


Some of the better surge protectors will come with a warranty on your electronics. Failure of a surge protector is determined by an internal sensor and whether or not it has melted. (One hopes that the internal sensor isn’t faulty, but we aren't going to discuss here whether you can actually collect on that warranty.)

Some Final Thoughts

Depending on the severity and location of a lightning strike, nothing will protect electronics if they’re plugged in during a close or violent lightning strike. The intensity of lightning cannot be overemphasized. For this reason, some people are huge proponents of lightning rods.

You will rarely only need the number of outlets for items you already own, so the best thing to do is to get a surge protector with more outlets than you need. These are also great to take when you travel, as we've never been in a motel room which had enough outlets for our electronics and fighting over them with your family members dampens vacation fun.

Power spikes aren’t just limited to outlets. Phone and cable also carry electrical spikes. Plan accordingly depending on the frequency of events in your area.

Surge protectors are not designed to handle constant overage, and, of course, it's best to have safe, quality electrical wiring in your home.