How to Install a Higher Amp-Rated Circuit

Turn off the main circuit breaker inside the electrical panel and unscrew the panel cover. Locate the electrical cable that you need to upgrade by tracing the cable from the outlet to the electrical panel. Inside the panel, wrap a band of electrical tape around each wire to identify the wires that must be replaced. A regular 110-volt circuit has a white (neutral), black (hot) and green or bare (ground) wire.

Unscrew the marked wires from their corresponding terminals: black wire from the circuit breaker, white wire from the neutral buss bar and green wire from the ground buss bar. Straighten out each wire. Pry up the circuit breaker with a flat-head screwdriver and unplug the breaker from the panel board.

Unscrew the faceplate of the outlet belonging to the circuit that needs to be upgraded. Unscrew the outlet from its outlet box; note how each wire inside the box is wired. Unscrew each wire attached to the outlet and remove the outlet.

Replace the electrical cable with a similar-colored, similar-length but higher-amperage cable. Run the new electrical cable from the electrical panel to the outlet box following the route taken by the old cable. Fasten the cable onto surfaces using cable staples.

Slip one end of the cable into the outlet box. Strip off 2 inches of sheathing from the tip of the cable with diagonal pliers and then strip off ½ inch of insulation from the tip of each exposed wire, using a wire stripper. Hook the tip of the black wire clockwise around the brass-colored terminal screw on the outlet; hook the white wire around the silver terminal screw, and hook the green or bare wire around the green grounding screw. Tighten each screw firmly.

Fold the wires in a zigzag manner and tuck them carefully into the outlet box. Push the outlet against the outlet box; fasten the outlet to the box, using screws supplied with the box. Replace the outlet faceplate.

Plug the new 110-volt circuit breaker into the vacated slot in the electrical panel. Slip the other end of the cable into the electrical panel. Route the green or bare wire to the grounding bar. Route the white wire to the neutral bar, and route the black wire to the end of the 110-volt circuit breaker that you just installed. Cut any excess wires, using diagonal pliers, and strip off 1/2 inch of insulation from the tip of each wire.

Plug each wire into its corresponding terminal screw in the following manner: green wire to the grounding bar, white wire to the neutral bar and black wire to the terminal screw at the end of the 110-volt circuit breaker. Tighten each terminal screw to secure all connections. Pull on each wire to check for any loose connection. Replace the cover of the electrical panel and turn on the main breaker. Plug an appliance into the outlet to test the connection.