By Bob Beacham | Updated Jun 13, 2023 6:27 PM
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Extreme weather conditions like hurricanes, tornadoes, blizzards, and thunderstorms pose obvious power-outage threats, but other factors contribute to voltage surges more often than you might realize. Faults or fires in main transformers or generating equipment can cause a disruption in your home’s power supply. Additionally, brownouts, or drops in voltage in an electrical power supply system, often result in a surge as power is restored.
These incidents are far from unusual. A power surge may last only a fraction of a second, but the results inside the home can be long lasting or even catastrophic. Excess electricity has the capacity to damage everything from a computer, TV, or refrigerator to the compressor of an HVAC system.
Fortunately, devices to prevent these problems are surprisingly affordable—particularly when weighed against the cost of damaged items that would need to be replaced. This guide will help you determine how to choose the best whole-house surge protector for your property.
As an engineer and home remodeler, I have some experience with surge protection devices (SPD). For those without electrical knowledge, the field can be a confusing one, so I tried to keep the selection criteria as straightforward as possible.
Generally speaking, a higher kiloAmps (kA) rating means greater protection. Some devices suppress surges better than others, and the most advanced models may have a comparatively low kA rating. National Electrical Manufacturer Association (NEMA) ratings are key to knowing which device can be installed where, so we chose a number of alternatives to maximize user choice. (For more information on kA ratings, read the section Voltage and Surge Protector Ratings below our product reviews.)
Finally, premium brands may offer extensive features and high levels of protection, but not everyone feels they are necessary. As a result, we’ve included devices at various price points.
Each of these SPDs has its own unique features and benefits, and the following categories should help you quickly identify the best surge protector for your situation.
Siemens offers a range of surge-protection devices. The FS140 is their premium model, offering the highest protection on our list at 140kA. It comes with a tough thermoplastic NEMA 4X-rated case and can be fitted to any main breaker panel via a double-pole circuit breaker of 30 amps (A) or less.
Commercial-class diagnostics means there are three stages of alert, including an audible alarm and flashing red LED light if the electrical system is unprotected. Siemens coaxial and digital subscriber line (DSL) phone and modem protection devices can be added to provide comprehensive coverage, though it costs extra.
This device is a bit more expensive than much of the competition, but this level of protection should offer peace of mind even in lightning-storm-prone areas.
Get the Siemens whole-house surge protector at Amazon, Lowe’s, or The Home Depot.
Equally suitable for residential and light commercial use, Leviton’s easy-to-install Type 2 surge protection panel is designed for easy flush mounting beside the main breaker panel. In that position, it offers an instant visual reference to protection status via front-mounted LEDs. The J-box metal enclosure is prepunched for standard electrical conduit connections and is NEMA 1 rated for indoor use.
In line with its potential use in mixed commercial environments, there’s a tremendous amount of technical information displayed right on the case front. Offering 50kA protection for single-phase supply, this device can be integrated with Leviton’s smart Dacora Home Controls.
Get the Leviton 51120-1 whole-house surge protector at Amazon or The Home Depot.
Eaton has built a reputation for reliable and durable equipment at competitive prices, and its Type 2 SPD is no exception. It offers excellent protection in an affordable package.
The compact unit can be installed indoors or out and is easy to mount thanks to an innovative universal design that can be adapted to almost any panel. The NEMA 4 case is unusual on a budget device and capable of protecting the internal circuitry from rain, snow, and ice.
The Eaton Type 2 SPD is Underwriters Laboratories (UL) listed and offers the standard four protection modes. LED indicators give clear indication of status. The unit has a maximum surge protection rating of 36kA, though it may be defeated by a direct lightning strike.
Get the Eaton CHSPT2SURGE whole-house surge protector at Amazon or The Home Depot.
This high-quality Type 1 whole-house surge protector from Schneider Electric offers the ultimate in versatility. The compact unit features a NEMA 4X case, can be installed indoors or out, and is designed to be fitted on the line side of any residential breaker panel.
Whereas most surge protectors offer four modes of protection (the way the surge is channeled away from the home’s electric devices), the HEPD80 offers six. While this feature is perhaps only of interest to professional electricians, it can increase the margin of safety provided.
Despite its impressive 80kA protection level, the HEPD80’s outstanding performance doesn’t also come with exorbitant pricing, as this unit remains a very affordable option. It is both UL listed and Canadian Standards Association (CSA) certified.
Get the Schneider Electric whole-house surge protector at Amazon, Lowe’s, or The Home Depot.
The Eaton CHSPT2ULTRA is another example of this leading brand’s reputation for high-quality surge protection devices that won’t break the bank. Like the model we recommend as Best Bang for the Buck, this model has a tough NEMA 4 case that provides all-weather protection or can be fitted indoors. Because this compact SPD is installed outside the breaker box, it can be combined with any manufacturer’s load center.
With single surge protection of up to 108kA, this is one of the highest-rated Type 2 devices we found, and equally suitable for residential or commercial use on 120 or 240-volt lines. It offers four modes, useful LED status indicators, and is UL listed for safety.
Get the Eaton CHSPT2ULTRA whole-house surge protector at Amazon or The Home Depot.
Flush mounting a surge protection device can result in a more attractive appearance, and while this isn’t always a consideration, it may be a factor when the device is visible. While the Leviton 51110-SRG can be used in individual residences, it is designed to be used in service entrances to apartments and condominiums, where it will certainly look neater than many rivals. The enclosure is NEMA 4X rated, and so it’s also perfectly safe for outdoor use.
Technical specifications can occasionally be confusing, and this Leviton SPD is described as providing 24kA per mode, which doesn’t seem particularly high. However, it actually has two modes that work together, and thus the true protection rating against any surge is a competitive 48kA. Given the low price, it is an excellent value.
Get the Leviton 51110-SRG whole-house surge protector at Amazon or The Home Depot.
Another versatile option, the Intermatic IG1240RC3 can either be installed line side by a professional electrician as a Type 1 device for the main power line or as a Type 2 device alongside the main breaker panel. The robust rainproof plastic case is rated NEMA 3R for use indoors or out. Protection of up to 50kA is provided via up to six modes.
A unique facet of this device is that it uses replaceable modules. Virtually every other whole-house surge protector has to be replaced in its entirety after one or more surge incidents, depending on severity. Instead, the Intermatic allows for replacing individual modules, which can be done by simply disconnecting the device. Over time, this could result in considerable savings, especially in areas subject to frequent lightning strikes.
Get the Intermatic IG1240RC3 whole-house surge protector at Amazon or The Home Depot.
This high-quality Type 1 and 2 whole-house surge protector from Intermatic is one of the most advanced systems currently available and uses Thermally Protected Metal Oxide Varistor (TPMOV) that dramatically reduces the chances of unexpected failure. Installation can be before or after service entrances and utility meter cabinets, but the case is only rated for indoors, not out.
Whereas most surge protectors have four modes of protection (the way the surge is channeled away from the home’s electric devices), the IG2240 offers six. With 50kA per channel, and two channels, the protection rating totals an impressive 100kA, which should be sufficient for just about any surge event.
The UL-listed Intermatic surge protector has clear LED indicators for on and protected states. Should one of the three independent modules fail due to overload, a built-in power switch means the surge protector can be isolated, making replacement easy and safe.
Get the Intermatic IG2240-IMSK whole-house surge protector at Amazon or Lowe’s.
Before you hit the ground running, it’s important to have a solid understanding of the relevant features of whole-home surge protectors and how they will affect your purchasing decision. The following provides a comprehensive guide to many of the technical and safety considerations to keep in mind while shopping for the best whole-house surge protector.
Although commonly called “surge protectors,” technically these are “surge protection devices.” When considering which is the best SPD for your home, you will want to take into account which category they fall under. Some are designed to shield individual items from the damage caused by power spikes, whereas others—which are the main focus of this article—offer whole-house surge protection. There are two distinct forms of the latter, making three types of SPDs in total.
Type 1 devices offer the highest level of protection from external sources and also provide general protection from internal power surges. Low-power spikes might get through, but those are generally nondestructive. These surge protectors are installed where the supply from the utility company meets the main breaker box—what’s termed the “line side.” This means power cannot get into the home without flowing through the SPD, so only safe levels of electricity make it through.
Installation requires that power to the home be disconnected while work is carried out. The installation must also be undertaken by a qualified electrician, which can add considerably to the cost. In some cases, it’s necessary to inform the utility company before work is carried out, though the contractor should arrange that.
Perhaps the most popular kind of SPD, Type 2 surge protectors can be installed inside the main breaker panel, also called a load center, or somewhere beside it. Installation can be accomplished by any DIYer with the requisite electrical experience. That said, while it isn’t necessary to have a qualified electrician do the job, those who are not completely confident in their abilities should at least consult one.
Depending on user configuration, Type 2 SPDs can protect an individual circuit or all the circuits within an electrical panel, plus subsidiary panels downstream of it. Many provide similar levels of protection as Type 1 devices, but it’s important to check the specifications.
Note: The latest code from the National Fire Protection Association proposes all new homes have Type 1 or Type 2 devices installed as standard and that any replacement service panel installed in existing homes includes one.
Generally called “strip surge protectors” or “receptacle surge protectors,” these are popular, low-cost devices that plug into any household outlet. They typically have four to six additional outlets and are a convenient way to protect low-power devices like TVs, computers, or gaming consoles.
Technically, these gadgets are surge arresters. Unlike Type 1 and Type 2 surge protectors, they don’t absorb excess power but rather transfer it to the ground wire. While they are effective in the majority of cases, it would be wrong to assume they offer total protection. It’s also important not to confuse them with ordinary power strips, which often look similar but do not have a surge-protection element.
UL, formerly known as Underwriters Laboratories, is an independent organization recognized worldwide for safety testing and certification. The current standard for surge-protection devices is UL 1449 (3rd Edition). The term “UL listed” is frequently used. Whole-house surge protection devices should also be listed as a Transient Voltage Surge Suppressor (TVSS) and typically are labeled as such on the device.
UL 1449 covers numerous aspects of the SPD, including how fast it reacts to a surge, the current required to trip it, and the level of protection offered. In order to pass, a whole-house surge protector must be able to produce results within the specified limits for as many as 15 consecutive tests.
Devices may also be CSA rated. This is a highly regarded global organization, and certification underlines the high safety standards of the device.
The nominal voltage in the U.S. (the voltage provided at your household outlets) is 110/120 volts. In many other countries, it is 220/240 volts. Whole-house surge protectors are frequently capable of switching to either, but it is worth checking.
The maximum continuous operating voltage (MCOV) is the amount of voltage the surge protector will allow through without tripping. Having the device trip every time the power hits 121 volts, for example, would cause unnecessary wear, so the MCOV is set a little higher. Generally, this provides a margin of between 15 percent and 20 percent. For example, a 120-volt surge protector with a 20 percent margin would have an MCOV of 144 volts.
Manufacturers of whole-house surge protectors often use terms like “high voltage protection.” A lightning strike can send 30,000 volts into a household electrical system, so protecting against that kind of power certainly sounds impressive. However, while the voltage protection rating is calculated by UL and CSA in their testing, they are often not prominent within the product details.
More often, the headline figure is the surge-protection rating. This is the amount of electrical current that can be absorbed, measured in kA, which is thousands of amps. The minimum is usually 10kA (10,000 amps), but it depends on the device type. The best whole-house surge protectors are generally rated from 30kA upward. That’s usually sufficient to deal with the worst storms or power generation problems, though far higher limits are common.
NEMA has a standardized rating system covering electrical device enclosures used in the U.S. It specifies the environments where a particular device can be installed and used safely.
There are two aspects to NEMA ratings: the protection the enclosure offers to the equipment inside against dirt, dust, etc., and the protection the enclosure offers to personnel who might come into contact with the enclosure.
Whole-house surge protectors vary considerably. NEMA 1 is the lowest rating, stating that an enclosure is for indoor use and provides basic protection against possible electric shocks. At the other end of the scale, a NEMA 4X-rated product is suitable for indoor or outdoor use, including offshore, and offers protection from windblown dirt, sand, rain, and more. Avoid purchasing an SPD that does not have a NEMA rating.
While a single surge is unlikely to knock out your protection completely, it’s possible that after numerous events, the unit may fail. If the SPD has done its job properly up to that point, you may not even be aware of a problem. Fortunately, even the most basic whole-house surge protection device has an LED display to show that the unit is operational.
More complex models may feature additional lights to show a fault condition, while others have audible alarms. For those who utilize smart technology in the home, there are some options that can integrate with smartphones and home automation systems to send details of a surge event, or surge protection status, to a smartphone or tablet.
Type 2 whole-house surge protectors can be installed by anyone with sufficient knowledge of how the main breaker panel functions. The number of breaker spaces required and their amperage can vary. It’s important to understand you are dealing with high voltages, so if you have any doubt or uncertainty about your abilities, it’s recommended that you talk to or hire a qualified professional electrician.
Type 1 whole-house surge protectors are line-side devices, which means they are fitted between the external utility cable and the main breaker panel. Installation of these devices must be carried out by a certified electrical contractor. Not doing so will almost certainly invalidate any home insurance should a fire or fault occur. Additionally, this may be illegal and could result in you being prosecuted by your utility company because line-side cable and equipment belong to them.
A whole-house surge protector is a product that often doesn’t get the attention it deserves. As a result, whether it’s worth installing one is a common question. They offer a multitude of benefits, including:
You may still have a few unanswered questions about surge protectors for the home. Some of the more common queries are addressed below. It’s also worth checking out our useful power outage survival guide.
A power strip simply provides additional outlets. Surge protectors can look very similar but include devices to prevent power spikes from damaging the equipment plugged into them. True surge protectors will detail the protection provided.
The right SPD for your needs will depend on your home setup, types of electronics and appliances you’d like to protect, and frequency of high-risk events such as lightning storms or power surges. The considerations outlined above should offer considerable guidance, but if you are still not sure which device is right for you, consult a suitably qualified electrical professional.
The best whole-house surge protector will prevent external power fluctuations from damaging equipment inside the home. They can also prevent feedback from internal surges traveling through the breaker system. However, a best-case scenario is to protect sensitive electronics with a strip surge protector as well.
Yes. The recommended minimum protection from a whole-house system is 40,000A, though many are much higher. A lightning strike is usually around 30,000A. That said, it’s always advisable to unplug what you can if a lightning storm is imminent.
It’s impossible to say because component wear depends on the frequency and severity of power surges. Many manufacturers claim a life expectancy of 5 years or more, although 10 years is not uncommon. However, some low-cost devices may need to be replaced after just one significant lightning storm. If temporary loss of power is a major concern, you might want to consider a back-up generator.
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