Most voltage surges start inside your home or building and are due to equipment cycling on and off. Outside your home or building, lighting, animals, traffic accidents, switching on the power system, equipment breakdowns and other events can also cause voltage surges.

A large surge, during a lightning storm for example, might damage some electrical equipment suddenly. Equipment may also be damaged gradually due to the smaller voltage transients that regularly occur as other nearby equipment switches on and off.

• UL Listed: These surge suppressors meet the Underwriters Laboratories (UL) standard 1449 3rd or 4th edition
• A joule rating of 500 joules or more
• An outlet space for each piece of equipment on the surge suppressor
• Room to plug in AC and DC adapters
• If you’re protecting a television, computer, modem, or similar equipment with coaxial cable, network and/or phone jacks, get a surge suppressor with connections for these communication lines to protect your equipment from surges on these other systems
• Status or indicator lights to show the device is functioning properly (not just that it’s on)
• Protection for electromagnetic interference (EMI)
• Protection for radio-frequency interference (RFI)
• Warranty and insurance: Five years on the suppressor and coverage for your connected equipment

Other Things to Consider:

• Avoid simple outlet strips that provide no protection for your equipment.
• Expect to pay $25 or more for a good surge suppressor.
• A surge suppressor works only when plugged into a properly grounded, three-prong outlet.
• If your house is older and has two-prong outlets or improperly grounded three-prong outlets, have a licensed electrician upgrade your outlets.
• You might find third-party reviews and evaluations of high-quality surge suppressors helpful.

• Power outages or power sags
• Nearby lightning strikes
• Sustained overvoltage events

• The UL 1449 standard was updated in 2014. If your surge suppressor was manufactured before 2014, it may be less effective and offer less protection.
• If it’s discolored, overheats or shows signs of melting, replace it immediately.
• Surge suppressors gradually wear out. If yours doesn’t have indicator lights indicating it is functioning properly, it should be replaced.

• Yes. Surge protection at your electric service panel helps protect your home or business from surges originating outside the building.
• Electrical panel surge protection also helps prevent surges on one circuit from affecting equipment on other circuits served from that panel.
• Using surge suppressors in your home or business offers another layer of protection for electronic equipment.
• Interested in installing electrical panel surge suppressor? Idaho Power recommends contacting a licensed electrician.