A whole-house surge protector can help reduce some lightning-related surges that travel into a home through the electrical service, but it cannot protect against a direct lightning strike or guarantee that equipment will not be damaged. It is one layer of protection, not a complete lightning protection system.
Understanding its limits helps set realistic expectations.
How Lightning Causes Electrical Surges
Lightning does not need to hit a house to cause trouble. A strike on or near power lines, or nearby ground, can send a surge along utility wiring and into homes. These indirect effects are the type of surge a whole-house device is most able to help with. Lightning can also affect underground lines and nearby structures, and the resulting surges vary widely in size.
Surges can also enter through other connections, such as cable, phone and data lines, which do not pass through the electrical panel. A device at the panel does not protect those paths unless they are separately addressed.
The Limits of Surge Protective Devices
A direct strike, or a very close one, releases far more energy than a residential surge protective device is designed to handle. A consumer surge protection paper prepared with the National Institute of Standards and Technology noted that there is little that can be done in typical homes to prevent damage from a nearly direct strike.
Surge protection is also different from a lightning protection system. Lightning rods, conductors and grounding systems are designed to give a strike a path to ground around a building, which is a separate specialty from electrical surge protection.
Installation, Grounding and Bonding
A surge protector depends on a good path to ground. Its effectiveness is affected by the home’s grounding and bonding, the length of the connections to the device and whether the device is compatible with the panel. Checking these connections is often a sensible first step before adding any surge device.
Grounding and bonding are part of the overall electrical system, not something to adjust as a DIY project. An electrician can check these connections as part of planning surge protection.
Using Layered Protection
The most practical approach combines several layers: a whole-house device at the panel, point-of-use surge protectors for sensitive electronics, and protection for cable and phone lines where appropriate. Unplugging valuable electronics during severe storms and power outages adds another layer. Insurance coverage for surge damage varies, so it is worth reviewing your policy as well.
Storms in Utah can bring lightning and power outages, so planning protection before storm season is sensible. Even with every layer in place, no setup eliminates all risk.
If you want to reduce surge risk in your Salt Lake City home, our whole-house surge protection service can assess your panel and grounding and recommend a layered approach.