Whole home surge protection - one layer of two

What is whole home surge protection?

Whole home surge protection means fitting a surge protective device at or beside your service panel, where it clamps large voltage transients arriving on the incoming supply before they get into the house. It is the first layer of a layered scheme, not the whole of one - the panel device handles the big external event, and point-of-use protection at sensitive equipment handles what gets through and what starts inside the house.

Signs you need whole home surge protection

• You have added a meaningful amount of electronics to the house - controllers, access points, cameras, network gear - that all fail together if something arrives on the supply
• Your area sees frequent lightning activity, or your supply is overhead rather than underground
• The lights dim or flare when a large motor load such as a well pump or air conditioner starts and stops
• You have lost more than one piece of equipment to something nobody could explain
• A panel replacement, service upgrade or solar installation is already scheduled, which is by far the cheapest moment to add one
• You have equipment that is expensive or awkward to replace - a heat pump control board, an EV charger, a panel-integrated system
• Your existing surge device has an indicator light that has gone out or changed colour, which normally means it has done its job and is now inert

Seeing something not on this list? Browse smart home problems by symptom →

How whole home surge protection actually works

1. 1

   Establishing what kind of device your panel needs

   Devices intended for permanent connection at the service entrance or the panel are commonly described as type 1 or type 2 depending on where in the system they are fitted. Which is appropriate depends on your panel, your service arrangement and the manufacturer's instructions - this is a decision for the electrician, not a shopping preference.

   Watch forA device selected without reference to your actual panel. Compatibility with the make and model of the load centre matters, particularly for units that clip in as a breaker.

2. 2

   Working out where it connects

   Panel-mounted devices connect either as a breaker in a spare double space, or externally with short conductors landed into the panel. Either way, the connecting conductors need to be as short and as straight as practical, because length works directly against how well the device performs.

   Watch forLong, looping leads to a device mounted somewhere convenient. Extra conductor length between the device and the busbar measurably degrades the protection, and it is the most common installation shortcut in this job.

3. 3

   Isolating the supply - the genuinely dangerous part

   Switching the main breaker off does not make the panel safe. The conductors and lugs feeding that main breaker come from the utility and stay live regardless of its position. Work at the top of a service panel is done either with the supply pulled or disconnected by arrangement, or by someone properly equipped to work near live parts.

   Watch forAnyone treating "main breaker off" as an isolated panel. This is the reason this job is not a DIY project even for people entirely comfortable changing a breaker.

4. 4

   Checking the grounding and bonding first

   A surge device works by diverting energy to ground, so it is only as good as the grounding and bonding it is connected to. A competent installer inspects the grounding electrode arrangement and the bonding before fitting the device, because a poor ground makes the whole exercise much less effective.

   Watch forA device fitted without anybody looking at the grounding. It is the difference between protection and the appearance of it, and it costs nothing to check while the panel is open.

5. 5

   Adding the second layer at the equipment

   Point-of-use protection sits at the things you care about - network equipment, controllers, entertainment, anything with a delicate power supply. The panel device reduces the size of what arrives; the local device deals with the remainder and with transients generated inside the house by your own equipment.

   Watch forBeing told the panel device makes strips unnecessary. It does not, and no manufacturer of panel devices claims it does in their own documentation - that claim only appears in sales conversations.

6. 6

   Covering the other ways in

   A surge does not only arrive on the electrical service. Buried and overhead runs entering the building - coaxial, and anything metallic coming in from outside - are potential paths, and there are protective devices intended for them. A whole-house scheme that only considers the power feed has left a door open.

   Watch forOutdoor cameras and other exterior-mounted equipment on long runs back to a switch inside. Those cables are a route in, and they are frequently overlooked entirely.

7. 7

   Recording the install and knowing when it has expired

   These devices are sacrificial: they degrade as they absorb events and eventually stop protecting. Most carry a status indicator, which is the only way you will know. Note the install date, and make checking the indicator part of whatever else you check annually.

   Watch forAn indicator nobody ever looks at. A device that has already given its life is indistinguishable from a working one apart from that light, and a lot of houses are protected by a component that stopped working years ago.

What does whole home surge protection cost?

A panel-mounted device plus an electrician's attendance is one of the least expensive protective measures available, and adding it during a panel replacement or service upgrade costs very little extra. Point-of-use protection at equipment is a separate, modest spend. See the Cost Guide.

See the full whole home surge protection cost guide - by material, size and region →

If the number is the problem, here are the ways people pay for it →