Several companies make surge-protector breakers, which mount inside the box instead of outside. Unlike external surge protectors and the breakers they use, snap-in surge protectors do double duty – they protect your circuits, and you can use them as regular breakers. This makes them perfect in a breaker box without empty slots. The downside – snap-in breakers don’t protect you against as large a surge as external protectors. To install, turn off the power at the main breaker and remove two breakers. Connect the wires to the surge protector breakers and snap into place. Most breakers are specific to the type and manufacture of the box you have – ask before you buy one.
