How Do I Choose the Right Surge Protector?

By Vernon Trollinger, February 28, 2017, Home Improvement

Welcome to the How Do I Do This? series from Bounce Energy. Each month, we’ll dive into what it what you need to know to shop-for, install, or repair those things in your home to keep your life affordable and convenient. Plus, you’ll (hopefully) learn some useful tips for other projects along the way.

How Do I Choose the Right Surge Protector?

When it comes to protecting home electronics, the single most important accessory —apart from the parental “NO” –is a having a good surge protector in place. Surge protectors work by clamping down voltage spikes that can destroy the power circuits in anything that’s plugged into the wall. Most often, surge protectors are thought to protect against lightning strikes and while that’s true to an extent, most voltage surges originate inside your home because electric motors, lights, and power supply switching in your home sometimes emit a nano-second spike of high voltage, also called transient voltage, when they are turned on.

How Do I Choose the Right Surge Protector?

Transient voltage surges take just a nanosecond to burn out your electronics.

How High Can Surges Surge?

Ideally, your home’s normal AC current travels in a serene, balanced sine wave cycling 60 times a second (60 herz) and seldom rising between 110 and 120 volts. However, due to noise and voltage fluctuation in the grid, that voltage amount is just an average. Normal peak voltages can routinely hit 170 volts. While many electronics have some power filtering with limited surge suppression built in that can withstand this small spike, there are far bigger monsters lurking out there…2,000 volts or even more!

Can you say, “toasted circuit board”?

Surge suppressors are designed to allow a certain amount of overvoltage pass, usually no more than 300 volts AC. While that’s around three times more than the regular wall voltage, it’s still in the realm of safety for most power supplies to handle. Plus, it means the suppressor won’t have to clamp or absorb the energy from these little spikes as often. This is important because each time the suppressor clamps onto a voltage to dissipate it’s energy, it shortens its lifespan.

When a spike enters the suppressor, it passes through a bank of Metal Oxide Varisters (MOV). MOVs are wired from load to ground so they will resist the incoming energy and dump anything that goes over the 300 volts to the ground wire — which should flow down through your home’s grounding line to earth. That’s why it’s important to have your suppressor plugged into a grounded outlet. The problem with MOVs is they can only take so much of this kind of punishment until they wear out.

What’s the Right Kind of Surge Protection for Me?

How Do I Choose the Right Surge Protector?

Choosing the right surge protector for your home and family should be a calculated and well-informed decision.

It depends on how you’re going to use the surge protector and how much you can afford. While it’s true that lightning strikes to nearby power lines will probably fry your home’s electronics, remember that lightning strikes (whether nearby or far away) make up only a third of overvoltages and the majority come from sources inside your home.

Whole house surge suppression —If you want a thorough and complete voltage spike control system for you whole home, there are panel-mounted surge suppressors which connect directly into your home’s fuse box. These protect all the electrical lines in your home because the suppressor is connected directly to the electricity entering your home. Whole house systems can run from $50 to several hundred dollars depending on the suppressor’s power handling (rated in joules). Since these connect to your home’s electrical mains, it’s good idea to hire a professional to install it.

Transient Voltage Surge Suppressor (TVSS) receptacle or outlet — This is an outlet hardwired directly into one of your home’s outlet boxes. Though not an ironclad solution to lighting like a whole house suppressor, they can provide excellent protection to anything plugged into them. Different models will provide different levels of clamping ( 300 – 400 volts) and capacity (290 – 900 joules). Most come with light or alarm to indicate when they’ve been surged. The outlet will typically continue working but it’s surge suppression capacity might be reduced — and probably should be replaced. Average cost runs between $25 and $100 depending on amperage, capacity, and lights/alarms. If you’ve ever installed an outlet, it’s a simple matter of swapping out the old outlet for a new one.

Power strip with surge protection — These, as well as Uninterruptible Power Supply (UPS) that come with battery back up, are the most common kind of surge protection available. One common problem for consumers is that they assume the power strips have surge suppression capabilities. The important difference is that surge protected power strips will show their capacity rated in joules with cheaper ones running between 400 and 600 joules. Both surge protecting power strips and UPS systems provide a wide range of protection. The best ones are rated at 1,000 joules or more with some rated to 2630 joules selling for as little as $22.00.

To recap:

  • The lower the clamping voltage, the better. Look for 340 to 400 volts.
  • The higher the joules capacity, the better. Over 900 joules is good; over 1,000 is better.
  • Power suppressors don’t last forever. They take the hit to protect your equipment. You’ll want one that will safely disconnect from its power supply once it fails and also indicates that it has done so.
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About 

A native of Wyomissing Hills, PA, Vernon Trollinger studied writing and film at the University of Iowa, later earning his MA in writing there as well. Following a decade of digging in CRM archaeology, he now writes about green energy technology, home energy efficiency, DIY projects, the natural gas industry, and the electrical grid.

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