“Sock-It” to Damaging Power Surges in Your Home

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When it comes to illustrating the importance of whole home surge protection, few things are more impactful than a real life cautionary tale. Here’s one from the home renovation experts at “This Old House”:

“Not long ago, an electrical contractor was completely rewiring a 3,200-square-foot house in Acton, Massachusetts, when the owners decided to save some money and not install whole house surge protection against lightning or downed power lines. Shortly after the house was finished, lightning struck a utility pole near the house, sending a tidal wave of voltage through the wires, past the main breaker panel, and into the house. According to the contractor, it burned out the motherboard in the sub-zero refrigerator, fried the temperature controls in the double-wall oven, killed six dimmers, two computers, and every GFCI plug in the house.”

Damage total: $11,000

Average home surge protector: $50-350

Forgive us the pun, but…that’s shocking.

Think of home surge protectors as a tangible extension of your home insurance policy. This one, affordable device can save you thousands of dollars in property damage. You can’t control extreme weather or the risk that Mother Nature might target your home one day, but you can control the defense shields you put around your home in advance of a potential surge.

A surge protector (also called surge suppressor) is a device that is either hard-wired into your home’s electrical service panel protecting all circuits, or plugged in to protect one individual circuit. They serve as a type of “surge sentry”, letting current flow through them and only springing into action when a dangerous power spike is detected. That spike triggers the surge protector to cut power to your plugged in items and diverts it to the ground wire, usually in less than a nanosecond. When voltage returns to normal levels, electricity is restored to the house, unless the surge was so large that some fuses, outlets, or items were damaged.

We’ll talk more in detail about service panel and plug-in surge protectors in a moment, but first…

What Causes Power Surges?

Extreme weather such as hurricanes, tornadoes, snowstorms, thunderstorms, lightning strikes, and high winds are some of the most common causes, mainly because they damage nearby power lines, transformers, and stations.

Transformers and generating equipment are also susceptible to fires which can impact the power supply and cause surges. Sometimes, power companies will intentionally adjust voltage in an area for a variety of reasons, this is called a “brownout” and a surge can occur when full power is eventually restored.

How Do Surge Protectors Work?

There are hard-wired and plug-in models:

  • Hard-wired whole-house surge protection is hard-wired into your home’s service panel. At a minimum, these devices should be rated to stop a 40,000-amp surge and be able to handle between 200 to 400 joules.

Wait, what is a joule?

  • A joule is “a unit of work or energy equal to the work done by a force of one newton acting through a distance of one meter (a meter being about .0006 of a mile, the average width of a standard doorway.)
  • On a surge protector, the rating in joules indicates how much energy the unit can withstand before it fails. The higher the number, the greater the protection. The average mid-range, strong protection surge suppressor is around 600 joules.
  • Lights, alarms, and LED displays that indicate when a device is working properly, or when it has taken a hit, are also recommended additional features to consider.
  • Thermal fuses (or thermal cutoff) is an added safety measure against overheating. When a thermal fuse is hit with high voltage it does just what the name implies; it fuses together, shutting down the circuit so the spiking electricity cannot travel past that circuit and damage others. However, like a bee that dies after just one sting, a thermal fuse cannot be reused or reset after it’s shocked into action, it must be replaced.
  • Cost? For an average home with 200-amp power supply, it’s usually around $500, which includes an estimated two hours of labor.
  • DIY? No, this is a job for professionals like the highly-trained, certified, insured, and experienced electricians at On Time Electrical. Attempting to hard wire a surge suppressor into your electrical panel, if done improperly, can lead to shock and fire risk, property damage, and voided warranties.
  • Failure Rate? Hard-wired surge protectors are known to allow about 15% of excess current through during a spike. While this is certainly isn’t a huge amount, it is full disclosure to point out that hard-wiring does not mean “fool proof” surge protection. This is where plug-in models offer added protection and value.
  • Plug-in whole-house surge suppressors are essentially a “firewall” between individual appliances (and electronics) and wall outlets. Once you start researching your local market for one, you will see they come in a wide array of styles and price points. There are three basic types:
  1. The multi-outlet power strip (think “everyday power strip”, with surge protection features).
  2. The multi-tasking surge station with inputs for phone, cable, and power cords.
  3. The uninterruptable power supply (UPS) style that contain short-term battery backup in the event a power dip or blackout shuts down the outlet.


Recommended minimum performance standards for plug-in models:

  • Absorb at least 600 joules.
  • Meets UL Standard 1449 (second edition).
  • Designed to protect hot, neutral, and ground lines.
    • How to tell; look for “L-N, L-G, N-G” (line to neutral, line to ground, neutral to ground) on the product’s specifications.
  • Clamping voltage is 400 volts or less (this is the level of current that will trigger the device to direct electricity to the ground wire).
  • Lights, alarms, and LED displays to indicate a power surge was detected and diverted are also available on plug-in models.
  • Cost? It really is quite a range; some are as small as a plug-in air freshener, starting around $50-$70, while larger units can be the size of a throw pillow and cost around $350-$400.
  • DIY? Yes. However, even though they plug-in, they (along with hard-wired models) cannot offer the full protection you need if the home’s wiring isn’t properly grounded. There has to be a way for diverted current to leave the circuit(s). This is where a home electrical inspection by On Time Electrical experts can get you started on the right and safe path to surge protection.

Don’t end up a cautionary tale! Keep your home, property, and loved ones safe with whole-home surge protection, installed and tested to ensure it will perform properly should the need arise. On Time Electrical customer service is available 24/7 at (704) 820-4803. You can also visit us online anytime at www.itselectriccharlotte.com. Check out our weekly and monthly specials, plus we waive the service call fee on ANY repair! Locally owned and operated, we’re On Time Electrical. It’s electric!