Electrical surges are one of the major threats to electrical devices. They have the ability to completely fry any electrical circuit and, in some cases, even cause fires. So, whole house surge protectors act as a godsend for all electrical equipment for your entire household.

But many people might ask, how does a whole house surge protector work?

Basically, a whole house surge protector dampens any surge that might come through your supply. When the voltage in the circuit exceeds a certain threshold, the surge protector will create a low impedance path to the earth, so that the excess voltage does not affect any of your circuits at home.

In this article, I will go through the details of how a whole house surge protector works as well as what benefits it might provide.

How Does A Whole House Surge Protector Work?

What Are Whole House Surge Protectors?

A whole house surge protector is a device that saves your house from any electrical surges due to excessive voltage or a thunderstorm. It guides the excess voltage to the ground, instead of your house.

Large surges can occur as a result of a lightning strike, a downed power line, or any accident to the power cables, causing serious damage to appliances and your household circuitry. But smaller surges can be even deadlier. These smaller surges can cause as much damage to household appliances as the larger ones.

Fig 1- Whole House Surge Protectors
Fig 1- Whole House Surge Protectors

A whole-house surge protector diverts power down through the grounding power line, unlike power strips, which simply cut off the power when excessive voltage tries to pass through them. When the surge protector detects a voltage greater than its rated limit, flowing through the control panel, it safely diverts the excess voltage to the ground.

The surge protector will not function properly if it is not grounded. So proper grounding is a must for this. Some surge protection systems can withstand surges of up to 40,000 amperes. Surge protectors may also come with additional features such as indicator lights or alarms.

A whole house surge protector, that can provide surge protection from 20,000 amperes up to 40,000 amperes, can usually cost well and above $350. Excluding the electrician cost for installing it, which might take more than two hours even for an experienced professional.

How Does a Whole House Surge Protector Work?

The mechanism of a whole house surge protector can be divided into two key segments. Detecting surges, and diverting the surge. Let’s discuss the whole procedure.

Fig 2- Whole House Surge Protector Household Setup
Fig 2- Whole House Surge Protector Household Setup

Power enters your house through the supply cables. The power cables first come in contact with the surge protector. The surge protector continuously monitors the current and the voltage flowing through it. If the flowing current is well within the bounds, it will let it pass through to your devices.

But, if the current is abnormal in nature, it will either divert the excess electricity to the ground. Or completely shut itself off by cutting the power. Which in turn will protect all your devices from any abnormal flow of current that might have caused harm to them.

Basically, a surge protector has a filter that allows all electrical currents within the safe zone into your house, while preventing all irregular voltage from affecting your electrical appliances. As a result, all of your appliances are protected from burning out and, in some cases, exploding. It serves as the first line of defense against voltage spikes.

What Are the Benefits of a Whole House Surge Protector?

Whole house surge protectors not only save your equipment from electrical surges, but they also help from things like fluctuating voltages, increasing the longevity of your devices, etc. I will showcase some of the key benefits of a whole house surge protector below:

  • They protect your household from power spikes and surges up to 40,000 amperes (depends on which protector you install).
  • Whole house surge protectors shield your circuits from lightning strikes.
  • Small bursts of excess energy from major appliances cycling on and off account for up to 80% of power surges in your house, slowly degrading your appliances and shortening their lifespans.
  • Overvoltage from down utility lines and other nearby houses disrupts the flow of current into your home, causing dangerous voltage fluctuations. Whole house surge protectors can shield you from these.
  • Electrical appliances are no doubt an investment. Especially if you run home workshops. Any damage to your devices will be a loss to your business. So you may consider whole house surge protectors as extra insurance and business investment as well.
  • Not only does it protect your electrical appliances, but it also protects your entire electrical system. Any internal damage to your circuitry can not only be a huge hassle but extremely costly to fix.
  • Another important fact that is often looked over is that they provide peace of mind to the homeowner as well as the dwellers. You do not have to dread each lightning strike or a power outage. You can rest assured that your house is properly protected.

These are some of the key benefits of a whole house surge protectors. And it is true that they are extremely costly to install, the benefits far outweigh the effort and investment.


In this article, I have explained the procedure of how does a whole house surge protector works. I have also discussed their benefits and features.

I hope this article has given you a thorough understanding of how whole house surge protectors function. And whether you should invest in them or not.

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