What are "Mains"?

If you have never replaced your Federal Pacific breakers before, the thought of opening and working in your circuit breaker box can be quite intimidating. The circuit breaker box, also known as the electrical service panel, is the heart of your home's electrical system. You will need to know how to access this box sooner or later, so it's good to get familiar with it. When you open the breaker box you will see a set of FPE circuit breakers (or whichever make and model are used in your home) which are assigned to various parts of the home. At the top of the series are two circuit breakers called "mains". The mains are connected to the power cables from the electric company--the main flow of electricity, hence the name. The mains are your first line of protection in case of a power surge caused from outside the home. If there is a lightning strike in your area, the mains will trip to prevent the surge from flowing through the entire electrical system.