Whole-house surge protection: what it does and whether you need it
Updated · KeystoneProGuide editorial team
What is a power surge?
A brief spike in voltage. The Electrical Safety Foundation, a nonprofit electrical safety organization, describes a surge as a brief overvoltage event that can damage electrical devices and is a common cause of equipment failure. It lists the kinds of equipment whose lifespan surges can shorten: heating and air conditioning systems, washers and dryers, water heaters, ranges and refrigerators, lighting and entertainment systems.
Where do surges come from?
Mostly from inside the house, on the figures the foundation cites. It quotes the National Electrical Manufacturers Association's estimate that 60 to 80 percent of surges originate from internal sources (another foundation page gives 80 percent), and it divides the causes into two groups:
- Inside the home: large appliances switching on and off, faulty wiring or loose connections, overloaded or short circuits and ground faults, and the moment power comes back after an outage.
- Outside the home: lightning, damage to power lines and switching on the utility grid.
Those are the foundation's and the manufacturers' association's accounts; no government agency's figure on the share of internal surges was found for this guide.
What kinds of surge protection are there?
The foundation describes three types of surge protective device, often shortened to SPD:
| Type | What it is | Where it goes |
|---|---|---|
| Type 1 | Permanently connected; protects against external and internal surges | Inside or outside the home |
| Type 2 | Permanently connected; protects against internal or external surges | In or next to the breaker box |
| Type 3 | Point-of-use protection for individual devices | At the outlet |
It recommends using all three types for the best protection, and says a Type 3 device must be used together with a Type 1 or Type 2 to meet the 2020 code requirements.
How does whole-house protection differ from a plug-in protector?
In reach and in who installs it. The foundation's comparison rates point-of-use protection as good: it is easy to use, protects only what is plugged into it, and must be replaced over time or after a major surge. It rates whole-home protection as best: it must be installed by a qualified electrician, covers the whole electrical system including large appliances, outlets and switches, and handles larger surges for longer than plug-in devices.
The foundation also warns that power strips and surge protectors are not the same thing, and that not all power strips offer surge protection. The U.S. Fire Administration adds its own power strip advice: do not overload them, and use strips that have internal overload protection.
Does the code require surge protection?
For some work, by the foundation's account of the 2020 National Electrical Code. The foundation says that code requires new and renovated homes to be protected by listed Type 1 or Type 2 surge protective devices, and specifically that new and replaced service equipment must have one. That makes it most relevant when a panel or service is being replaced.
Which edition of the National Electrical Code your municipality enforces under Pennsylvania's Uniform Construction Code was not stated on any page read for this guide. Ask the code office or the electrician whether surge protection is required for your job. Installing a whole-house device in the panel is electrical work, and Pennsylvania's code regulation exempts only ordinary repairs from permits, so ask too whether a permit is needed.
What can surge protection not do?
Stop a direct lightning strike. The foundation says no surge protection can handle one, and advises disconnecting sensitive electronics if you suspect a surge is coming. The Public Utility Commission gives similar advice for outages: unplug sensitive electronics while the power is out, leave one light on so you know when it returns, and wait at least 15 minutes before switching other appliances back on.
Surge protection also does not deal with the internal causes the foundation lists. Loose connections, faulty wiring and overloaded circuits are faults to have repaired, not merely protected against.
Is it worth it?
That depends on the house, and the public sources read for this guide do not settle it with a cost figure. What they do say: surges are common, most start inside the home on the manufacturers' estimate, whole-house devices must be installed by a qualified electrician, and new or replaced service equipment needs one under the 2020 code as the foundation describes it. If a panel replacement or service upgrade is already planned, that is the natural moment to ask.
What should you ask the electrician?
- Is surge protection required for this job under the code edition enforced here?
- Will you install a Type 1 or a Type 2 device, and where?
- Is the device listed, and does the price include the permit?
- Which point-of-use protectors would you suggest for sensitive equipment?
- Are there loose connections or overloaded circuits that should be fixed as well?
The larger job that usually brings surge protection with it is covered in the panel upgrade guide, what to do when the power fails is in calling the utility or an electrician, and the tasks a homeowner can handle are in doing it yourself or hiring. Electricians are listed on the electricians directory page.
Sources
- Surge Protective Devices, Electrical Safety Foundation International (ESFI)
- Surge Protection - Keeping your Electronics and Home Safe, Electrical Safety Foundation International (ESFI)
- Home Safety Devices - Renovate Your Home to Code, Electrical Safety Foundation International (ESFI)
- Appliance and Electrical Fire Safety, U.S. Fire Administration
- Prepare Now for Post-Christmas Winter Storms - PUC Shares #UtilitySafety Tips, Pennsylvania Public Utility Commission
- 34 Pa. Code § 403.62. Permit requirements and exemptions., Commonwealth of Pennsylvania (Pennsylvania Code)