How to Add Electrical Circuits

Find the household electrical service panel. This is generally located in the basement or garage.

Turn off the main power to the entire house. The main power switch is generally found next to or near the electric meter or next to the main service panel.

Open the service panel and test for voltage on the main bus bar running down the center of the service panel. Voltage should read "zero" there and at every other point in the service panel.

Pop out a round "knockout" on the side of the service panel opposite the installation location for the new circuit breaker with a screwdriver and hammer. Twist off and remove with pliers.

Install a cable clamp in the knockout.

Bring in the opposite end of the 14-2G length of electrical wire that runs from the new bedroom, and run it through the newly installed cable clamp. Leave enough length to easily reach the site of the new circuit breaker.

Clamp the 14-2G wire in the cable clamp tight enough to impair any movement, but do not crush the wire.

Strip off the white plastic sheath on the wire, exposing the three inside wires (usually black, white and bare copper) all the way back to the cable clamp. Strip about half an inch off each of the two covered wires.

Attach the bare copper ground wire to the ground bus bar (usually on the right of the service panel) where all the other ground wires are attached by putting the end of the wire in the ground slot and tightening the screw to hold the bare ground wire in place.

Attach the white wire to the neutral bus bar (usually on the left of the service panel) where the other neutral wires are attached by wrapping the half inch of bare wire clockwise around a loose screw and then tightening the screw. Alternatively, the neutral bus bar may have the same push-in-and-tighten fitting as the ground bus bar. If so, connect in the same manner as the ground wire.

Insert the stripped end of the black wire into the connection terminal on the end of the breaker with the exposed flathead screw, and tighten the screw.

Install the circuit breaker in the next empty spot on the central bus bar by sliding the slot on the underside of the breaker opposite the black wire onto the metal clip on the bus bar and pushing toward the panel when the circuit breaker reaches a point even with the breaker next to it. There will be an audible "click" as the breaker seats itself onto the bus bar.

Finish the wiring in the new bedroom or open the new circuit breaker before turning the main power back on.