Now that I'm up to my neck in a home addition, I need some information about swapping out old electrical receptacles for ground-fault circuit interrupters. CGFI units are almost always labeled, but should I use a multimeter to confirm the circuit map in the breaker?
Bob P. ~ Dallas, Texas
I would not worry about mapping out the circuitry of a GFCI outlet. They are all labeled on the back as to what connections do what. There is a Line side and a Load side to every GFCI outlet. The Line terminals are for the incoming power to the outlet.
If you connect other outlets to the Line terminals they will not be GFCI protected. If you connect additional outlets to the Load side of a GFCI outlet, those outlets will be GFCI protected. You can buy an inexpensive outlet tester, which will test GFCI outlets as well as standard outlets and tell you if everything is wired correctly.