Surge Protection

Surge protection? Boring and technical and way too may terms like amps, right? Think of whole house surge protection, like the doorman at a nightclub; the big, bulky guys with attitudes. While physical strength is important in the job, doormen need a variety of other abilities to succeed as well.

Well, a good whole-house surge protection device does essentially the same thing. It allows in, only the electricity your home needs and not the unwanted over-voltages from the utility provider. The whole-house surge protector then protects your devices from any trouble that can occur from surges inside the house.


80 percent of surges in a home we generate ourselves.

Like many of the surge suppression strips we’re used to, whole-house surge protectors use metal oxide varistors (MOVs), to shunt power surges. MOVs get a bad rap because in surge strips one surge can effectively end the usefulness of an MOV. But unlike those used in most surge strips, the ones in whole-house systems are built to shunt large surges and can last for years.

Many new homes being built today come with a whole-house surge protection as standard.

Homes have more electronics than ever. LED lights have a little circuit boards contained within. Washers and dryers have small circuit boards within them too. There is much to protect in a home, a lot of technology we’re plugging into our homes.

Surges come from more than just lightning. 80% of surges are transient (short yet intense bursts) and we’re the ones who are generating them. Generators and motors you have in a/c and appliances introduce a small surge of electricity into the electrical line. It is rare that one large surge will take out appliances and everything at one time. Mini surges will add up over the years, affect the performance of the electronics and cut short the anticipated life expectancy.

Overvoltage on the utility lines can also harm systems in the home and this tends to be the main reason for a whole house surge protection at the main electric panel. There is really no surge protection for a direct lightning strike. If a direct lightning strike concerns you look into a lightning rod.

An appliance or system on a dedicated circuit like an air conditioning unit will send the surge back through the breaker panel where it can be shunted to protect everything else in the home. Backup power generators can be a big culprit. If they’re connected to the electrical service to provide power to many circuits in the home and turn on automatically when power goes out. They can send power surges through the electrical lines that a whole-house surge protection system can shunt.

If an appliance or device sends a surge through a circuit that’s shared among other devices and not dedicated, then those other outlets could be susceptible to a surge, which is why you don’t want it just at the electrical panel. Surge protection should be layered in the house to be at both the electrical service to protect the whole house and at the point of use to protect sensitive electronics. Power conditioners with surge suppression capability along with the ability to provide filtered power to a/v equipment are recommended for many home theater and home entertainment systems.

Most homes with 120 v service can be adequately protected with an 80kA-rated surge protector. Chances are a home is not going to see large spikes of 50kA to 100kA Even nearby lightning strikes traveling over power lines will be dissipated by the time that surge reaches a house. A home will likely never see a surge over 10kA.

Leviton is one of the companies at the forefront of whole-house structured wiring, surge protection, lighting controls and other systems. We recently asked the company a few questions about the value of whole-house Surge Protective Devices (SPDs) and what builders should look for. Leviton makes a range of products that support a layered or “cascaded” system of surge suppression, starting at the electrical service panel or even at the meter, and ending with surge suppressing receptacles and USB charging ports.

With the popularity of home automation devices, smart appliances and other electronic equipment in today’s homes, the requirement for “whole house” surge protection has become a necessity. The bottom line is that surges or spikes can actually destroy any sensitive electronics within the devices we use in our homes, such as HDTVs, DVRs, computers, refrigerators, microwave ovens and more. Damage can range from complete failure to a reduction in useful life. To some, whole-house surge protection is achieved simply by installing a surge protective breaker or panel at the home’s main breaker load center(s). However, true whole-house surge protection requires surge protective devices at various levels within the home to provide the most reliable protection: a surge protection network, if you will.

Having a tiered approach drops the incoming surge energy to a more manageable level for the equipment being protected. Each Surge Protective Device reduces the spike/surge to some extent, but there is always residual energy that gets through, so having a tiered approach allows the next SPD in the circuit to lower that surge energy and bring it closer to the intended power system voltage (i.e. 120V AC). Internal power surges, such as from power tools or vacuum cleaners, can generate surges back into the home’s electrical system, so the tiered approach provides surge protection there as well.

TecHome: What are some features and specs homebuilders should look for?

SurgeProtectorLeviton: Homebuilders should always look to see if the Surge Protective Device is listed as UL 1449 3rd Edition

compliant; look for the “Type” designation on the product and make sure the device is listed as a Type 1, Type 2, Type 3 or Type 4 Surge Protective Device.

Surge panels may be installed either indoors or outdoors. If you’re installing an outdoor panel, be sure the device is listed as NEMA 3R, 4 or 4X rated. For mounting surge panels indoors, the Leviton 51120-1 or the 42120-1 provides enhanced noise filtering with superior surge protection. These devices are mounted to the load side off the main disconnect switch of an electric service panel and protect against residual lightning energy and other externally generated surges, such as those caused by utility company capacitor back-switching.

If you’re using DHC/X10 (Decora Home Controls) in your home, another surge panel from Leviton that you should consider is the 32120-1 (or even the 52120-M2H for a large residence).

For surge receptacles you should consider the following two features:

  • Tamper-resistant receptacles that are safer for children and meet the latest National Electrical Code requirements, such as the Leviton T5280 series.
  • An audible alarm that alerts you when the surge protection has been compromised. The alarmed surge receptacles are available from Leviton in either tamper (T7280 Series) or non-tamper-resistant (7280 Series).

TecHome: What technologies do you use in your residential surge protection products?

Leviton: Our Surge Protective Devices feature Metal Oxide Varistors (MOVs), which are the industry standard due to their reliability, durability, availability and reasonable cost in a price conscious market. MOVs divert the extra energy from a surge to ground or neutral in the Surge Protective Device, protecting your equipment and other devices on the circuit.

TecHome: Any issues with using meter sockets? Why not just protect at the circuit panel?

Leviton: Meter socket adapters typically require support from the local utility company in order to be installed. Just having a Surge Protective Device at the circuit panel is not enough to provide a true whole house surge protection network. The tiered approach is necessary to fully suppress the surge event to a manageable level for downstream electronic devices.

TecHome: Are surge-protected receptacles becoming more popular? Then again, why bother if using whole-house protection?

Leviton: Surge receptacles are becoming more popular again due to the increased awareness of the benefits of the tiered approach. Note that without the third level of protection, you do not truly have whole-house surge protection. The best protection is found when the Surge Protection Device is close to the equipment that is being protected; therefore surge receptacles are really your last line of defense.

TecHome: Are any of Leviton’s USB charger outlets surge-protected (both for the electrical and USB outlets)?

Leviton: Leviton manufactures a wide array of receptacles with surge protection. However, we are not aware of any USB outlets currently available in the market that meet the UL 497B standard of surge protection.