You might think that your household power supply is pretty consistent. Although extreme weather conditions like hurricanes, tornadoes, blizzards, and even just thunderstorms or high wind pose obvious power-outage threats, power surges and spikes unprompted by weather happen more often than you might realize—and can be caused by a variety of things.
Faults or fires in main transformers or generating equipment can cause a disruption in your home’s power supply, and brownouts, which are intentional or unintentional drops in voltage in an electrical power supply system, often result in a surge as power is restored.
These incidents, which can happen in the blink of an eye, are far from unusual. A surge might 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.
- BEST OVERALL: Eaton Ultimate Surge Protection 3rd Edition
- RUNNER UP: Siemens FS140 Whole House Surge Protection
- ALSO CONSIDER: Leviton 51120-1 120/240 Volt Panel Protector
- ALSO CONSIDER: Intermatic Whole Home Surge Protection Device
Types of Surge Protectors
Although commonly called “surge protectors,” technically these are “surge protection devices” (SPDs). When considering which is the best SPD for your home, you need 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 non-destructive.
These surge protectors are installed where the supply from the utility company meets the main breaker, 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 a 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 (NFPA) 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.
What to Consider When Choosing the Best Whole-House Surge Protector
Before you hit the ground running, it’s important to have a solid understanding of the relevant features of whole-house 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.
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 protectors 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 Canadian Standards Association (CSA) rated. Despite the name, this is a highly regarded global organization, and certification underlines the high safety standards of the device.
Nominal and Maximum Continuous Operating Voltage
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.
Voltage and Surge Protection Ratings
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 kiloAmps (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 Enclosure Type
The National Electrical Manufacturers Association (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 gives 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 protectors have 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 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.
Our Top Picks
Having had the chance to read about the types of surge protectors and their main performance criteria, it’s now time to consider the best options on the market. Each of these SPDs has its own unique features and benefits, and the following categories should help you quickly and easily identify the best surge protector for your situation.
Choosing a single best whole-house surge protector is no easy task, but the feature-rich Eaton gets top marks for its versatility, outstanding 108kA protection rating, and clear status signaling.
This is a Type 2 device and can be fitted either inside the main breaker panel or alongside it. It is supplied ready to install, though an additional 50-amp double-pole breaker may be required.
Two LEDs alert the user as to whether the unit is active, has experienced a surge but is still functioning, or needs to be replaced after multiple incidents. Given its high kA rating, the latter may never happen.
The Eaton is UL-listed and is rated NEMA 4X for both indoor and outdoor use. It also offers the ability to protect phone lines, internet, and cable, something that is frequently overlooked.
Siemens offers a range of surge protection devices. The FS140 is their premium model, offering 140kA protection in a tough, thermoplastic NEMA 4X-rated case. It can be fitted to any main breaker panel via a double-pole circuit breaker of 30A 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 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.
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 pre-punched 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.
Another versatile option, the Intermatic can either be installed line side by a professional electrician as a Type 1 device 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 storms.
The Advantages of Owning a Whole-House Surge Protector
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:
- For a comparatively low cost, an SPD protects not just your sensitive electronic devices but also your HVAC and other major appliances. That could result in savings of thousands of dollars, particularly in areas where lightning storms are common.
- Around 80 percent of power surges happen within the home. They may be small, but the cumulative effect is that they shorten the life of any device that’s permanently plugged in, even while in standby mode. Whole-house surge protectors prevent that.
- For households that rely on well water, these devices can prevent loss of water supply.
- A number of home insurance policies do not cover damage caused by power surges.
FAQs About Whole-House Surge Protectors
The information above will no doubt have left you better informed about the features you’ll want to look for when choosing the best whole-house surge protector. It will also have given you insight into some of the best products currently on the market. However, a few questions may remain unanswered. Some of the more common queries are addressed below.
Q. What is the difference between a power strip and a surge protector?
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.
Q. How do I choose a whole-house surge protector?
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.
Q. If a surge comes from appliances like AC units and larger appliances, do I still have device protection before the breaker panel?
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.
Q. Do whole-home surge protectors work against lightning?
Yes. The recommended minimum protection from a whole-house system is 40,000 amps, though many are much higher. A lightning strike is usually around 30,000 amps. That said, it’s always advisable to unplug what you can if a lightning storm is imminent.
Q. How long does a whole-house surge protector last?
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.