Dear Mr. Electrician:  What are the best whole house surge protectors that will protect my computer from lightning, and how do I install them?

Answer:  The best whole house surge protectors will protect your home and appliances from lightning strikes, power surges, solar flares, and electromagnetic pulses.

Methods to install whole house surge protectors vary slightly between devices and the type of main electrical panel.  However, installing a surge protector on your main electrical panel is relatively easy compared to other electrical wiring tasks.  Installation of surge protectors can be hazardous because of the live electrical components you have to work around.

NOTE: Text links below go to applicable products on Amazon and EMP Shield.  As an Amazon Associate, I earn from qualifying purchases.

Finding the best surge protectors that will protect your computer from lightning will involve looking at the various specifications of the many brands of surge protection devices.

In addition to surge protection, consider a device that also offers protection from Solar Flares and Electromagnetic Pulses, both of which can be harmful to your home’s electrical system.

Do some homework before making a surge protector purchase.  Read reviews from other purchasers, compare the product ratings, and check the price ranges for your budget.

Read the manufacturer’s installation instructions before purchasing.  Many installation instructions are available online.


A type 1 surge protection device is rated for the line side of an electrical service before the main disconnect.  The power company would most likely install this type.

A type 2 surge protection device is rated for the load side of an electrical service after the main disconnect.  This would typically get installed inside or attached to your main electrical panel.

A type 3 surge protection device is typically the point-of-use plug-in modules, power strips, and surge receptacles.  They must be at least 30 feet or 10 meters away, as measured by the wiring distance from the main electrical service.  If less than 30 feet, they should also be rated for type 2.

A type 4 surge protection device shall only be installed by equipment manufacturers on or inside their distributed appliances and machines.


In my area, surge protectors installed in a main electrical panel must be inspected by the town’s electrical inspector.  An electrical permit must be applied for at the building department.  I submit a copy of the surge protector installation instructions with the permit application.

Suppose it is a complicated job or there are unusual circumstances. In that case, I will also submit a typed, one-page “Scope of Work” briefly explaining the planned installation and the materials to be used.

If there is something that the inspector doesn’t like, I prefer to know about it in advance rather than after the job is done.  Surge protection device installations are covered by article 242 in the 2020 National Electrical Code (NFPA 70).

Safety is paramount when working with electricity, and precautions should be taken.  Do not wear any jewelry, including watches and rings, tie back long hair, use insulated tools, and cover exposed bus bars.  Please read my post on being safe when working around your home for more tips.

Shutting off the main circuit breaker will help, but I am sometimes reluctant to do that on older electrical panels because there is a possibility that the main circuit breaker will not turn on again.

Also, just because the main circuit breaker is off does not always mean no electricity is flowing in the panel.  In some rare circumstances, stray current could be on the neutral conductor.  So with everything off, you should still treat it as being live.

The challenge that I mostly come across is finding enough space in the circuit breaker panel and the area around it to install the surge protection device.  It is particularly tricky when the circuit breaker panel is recessed inside a wall.

If it is in the garage, a hole could be cut in the wall below or above the panel, depending on which end has the least number of wires.

Sometimes in those circumstances, I would install a metal access panel due to the fire rating of the garage wall.  Other times I would use a surge protection device designed for recessed mounting.  Surge protection devices cannot be buried inside a wall where they will be inaccessible.

Surge protection for an electrical circuit breaker panel recessed in a wall
Surge protection for an electrical circuit breaker panel recessed in a wall.

The surge protection device above features a small status indicator display outside the panel.  Click here for details.  See the video down below for installation tips.  UL 1449 – Type 2 SURGE SUPPRESSION – Compliant

Many brands require their surge protection device to be connected to a dedicated two-pole circuit breaker.  However, I often find no available circuit breaker spaces available, or there is no two spaces side by side for an additional two-pole circuit breaker.

If there are no spaces side by side, I will move some of the existing circuit breakers around until I make room for a two-pole breaker.

Existing multi-wire circuits must have their breakers side by side and should be changed to two-pole circuit breakers or have approved handle ties installed while moving breakers around.  See Article 210.4(B).  Of course, everything moved has to be relabeled on the panel cover.

If the circuit breaker panel is approved for thin size or twin circuit breakers, I will install some of them to create additional spaces.

If there are no spare spaces, I look to see if every circuit breaker is actually in use and if I can double up some circuits onto existing breakers to free up two slots.  This must be done cautiously as I don’t want to cause a circuit breaker to overload and, consequently, trip off as the homeowner uses power.

I also do not want to cause any electrical code violations by doubling up circuits required to be separate such as the kitchen or laundry.

Some circuit breaker manufacturers have a combination circuit breaker and surge protector, which supplies whole house surge protection while not eliminating two circuit breakers.  Check with your circuit breaker panel manufacturer for what is approved to be installed in your panel.

EMP Shield distributes several devices that protect against surges and lightning strikes, solar flares, and electromagnetic pulses.  Surge protection devices are available for your car, home, antenna, Recreational Vehicle, and solar panels.

One particular item that I like is the surge protector made for circuit breaker panels recessed in a wall.  Many condos, apartments, and some residential garages have circuit breakers in a recessed main electrical panel. It is a challenge to fit a regular surge protector on the outside of them.

The EMP Shield surge devices are built to military standards and are competitively priced.  My link offers a $50.00 discount at checkout.

The EMP Shield is an electromagnetic pulse, Solar Flare, and lightning protection system designed to exceed the requirements of MIL-STD-188-125-1 for shunting over-voltage spikes.  See their surge protection devices here.  Installation guides are shown on their website for each application.  There is also a surge protector for European installations.

EMP shield also sells surge protection devices for RVs, motor vehicles, generators, and solar and wind generators.  MIL-STD-188-125-1 requires that the over-voltage spike from the E1 spike begin shunting 5,000 Amps within 20 nanoseconds.

All EMP Shield models start shunting overvoltage in 500 trillionths of a second.  EMP Shield is also designed to continue protecting through the expected durations of the E2 and E3 spikes produced by a high-altitude electromagnetic pulse.


Some whole-house Surge Protection Devices connect to a circuit breaker. In contrast, others are designed to connect directly to the main terminals in your electrical panel without any circuit breaker protection or disconnect.

Some surge protectors plug directly onto the bus bar inside an electrical panel in the same location that a circuit breaker plugs onto.  I prefer the type of surge protector installation that can be easily disconnected if necessary for replacement or servicing.

There are also plug-in surge protector modules made to protect one electrical appliance or component.  Surge protection power strips allow several electrical items to be plugged in and protected.  It is essential to read the labeling on these things.  Not all power strips have built-in surge protection.  You should only buy something that has a UL label or other testing laboratory approval.

In addition, there are surge protection electrical receptacle outlets that take the place of a regular outlet.  These are nice because they are contained in the wall so that you don’t have an additional corded device lying on the floor.

The 2020 National Electrical Code (NFPA 70) Article 230.67 requires an electrical service to a dwelling unit to have surge protection.

It is essential to read and follow the surge protection device manufacturer’s installation instructions.  The electrical inspector will follow what the manufacturer says.

Usually, the wire from the surge protector to the circuit breaker must be as short as possible.  Also, the required circuit breakers tend to have a higher ampere rating than what would typically be used on that size wire.

An Eaton surge protector mounted to an electrical circuit breaker panel
An Eaton surge protector is mounted to an electrical circuit breaker panel.

In the photo above, I put 3/8″ hex nuts under the mounting tabs of the surge protector to make it line up better with the existing 1/2″ knockout in the circuit breaker panel.

Sheet metal screws were used to attach it to the plywood backboard.  Fender washers between the nuts and the plywood prevented the nuts from being pulled into the wood when I tightened the sheet metal screws.


Protecting your computer, appliances, and other home electronics from lightning is not as simple as just installing a surge protector.  When a surge protector limits the high voltage from a lightning strike, it will need a means to dissipate the excess current.  The surge protector’s lightning current would automatically be diverted to earth in a well-grounded home.

The same is true for a plug-in surge protector power strip.  The plug-in receptacle ground is connected to the grounding electrode system for the entire house and will only be as effective as the entire grounding system.

The home’s metal water service pipe, ground rods, well casing, and other metal pipes can be part of the grounding electrode system.

In an older home, a weak link in the grounding electrode system due to a loose or non-existent connection or corrosion of a component may cause the surge protector to be ineffective or, in some cases, hazardous because it cannot dissipate the excess voltage.

The surge protector is connected to a dedicated circuit breaker as per the manufacturer's instructions. The manufacturer required that the wires be twisted together and that the surge protector gets connected to a 50 amp circuit breaker.
This surge protector is connected to a dedicated circuit breaker per the manufacturer’s instructions.

In the photo above, the manufacturer of the whole house protector specified in the instructions that the wires be twisted together and that the surge protector be connected to a two-pole 50 amp circuit breaker.

The instructions also said to keep the wires as short and as direct to the circuit breaker as possible.  I was lucky to have an open breaker slot and a 1/2″ knockout nearby.

Surge protection device connection to the main electrical panel
The surge protector is connected to the main electrical panel.  The manufacturer required that the wires be twisted together.  It is essential to follow the manufacturer’s instructions for the surge protector’s proper operation and pass an electrical inspection.

Before purchasing a surge protector, you should examine the main grounding electrode (Usually a water pipe or a ground rod or both) and the grounding electrode conductor connected to your electrical service.

Lightning will usually follow the most direct path of least resistance to earth, and you would prefer that it does not detour through any of your electronic equipment or appliances and cause damage.

Having an effective grounding system with surge protection will not only enhance the electrical safety of your computer equipment, but all electronic devices such as TVs, local network components, stereo amplifiers and receivers, microwave ovens, satellite dishes, appliances, and virtually anything else that is electronically or microprocessor controlled.

Main panel labeled with the surge protection device circuit breaker.  Although the wire attached to the surge protector was only #12, the manufacturer required that it be connected to a dedicated 50 amp circuit breaker.
The main panel is labeled with the surge protection device circuit breaker.  Although the wire attached to the surge protector was only #12, the manufacturer required that it be connected to a dedicated 50 amp circuit breaker.

Some suggested reading in the “National Electrical Code” are Article 250 Grounding & Bonding and Article 242 Overvoltage Protection.

For information about protecting your home against lightning strikes, you should read NFPA 780 Standard for the Installation of Lightning Protection Systems.

Main electrical panel with a surge protection device mounted to the left side
The main electrical panel with a surge protection device is mounted to the left side.

From the video above, whole house surge protectors are easy to install as long as you are comfortable working around live electricity.  If you have never worked inside an electrical panel before, do not do this yourself.  It is just too hazardous for a beginner.

Photo of an EMP Shield surge protection device designed for electrical circuit breaker panels that are recessed in a wall. It has a small status indicator display that mounts outside of the circuit breaker panel.  <a title="EMP Shield line of Surge Protection Devices" href="" target="_blank" rel="nofollow noopener sponsored"><strong>Click for details</strong></a>. UL 1449 - Type 2 SURGE SUPPRESSION – Compliant
Photo of an EMP Shield surge protection device designed for electrical circuit breaker panels recessed in a wall. It has a small status indicator display that mounts outside the circuit breaker panel.  Click for details. UL 1449 – Type 2 SURGE SUPPRESSION – Compliant

Leviton manufactures surge protection devices designed to be recessed in a wall.

A good post for you to read is how I grounded and bonded an older home due to the homeowner’s concern about lightning damage.

If you need to update your grounding electrode system, read my post.

This Old House has a short video about installing surge protectors.