How to Add a New Circuit Breaker Switch

The main power wire enters the house through the fuse box.

It does not happen often, but from time to time it is necessary to make alterations or repairs in your panel box, sometimes called a fuse box. Working in a panel box is no small affair. All of the electrical wiring in a house is connected to the panel box in some way and the main power wire enters the house through the panel box. Likewise, if you want to install a new circuit, you have to connect a new wire in the panel box and install a new circuit breaker switch.

Things You'll Need

• Circuit breaker switch
• Circuit wire
• Screwdriver
• Pliers
• Wire strippers

Instructions

1. Switch the main circuit breaker to the "Off" position. The power to the individual circuits is interrupted with the main switch off; however, the entrance cable, or the main power wire entering the panel box, is still live.

2. Remove the screws holding the panel box cover in place and set the cover off to the side.

3. Install the new circuit breaker in a vacant slot, directly under and against one of the existing circuit breakers. The end with the wire connection terminal locks in first. The end with the power bar slot locks in second. The power bar is in the center of the panel box. All of the circuits are powered by this bar.

4. Strip off 1/2 inch of the insulation on the end of the power wire that is feeding your new circuit.

5. Insert the power wire, the black wire, into the connection terminal on the new circuit breaker switch and tighten the terminal screw to secure the wire. Connect the neutral wire, the white wire, to the neutral bar and the ground wire to the ground bar in the same manner.

6. Remove the knockout that corresponds to the new circuit breaker from the panel box cover. The knockouts are pre-punched. To remove it, use your pliers to twist it back and forth.

7. Install the panel box cover and switch the main circuit breaker to the "On" position. Now you can test your circuit.

Tips & Warnings

• Circuit breakers should only be installed by a licensed electrician.

• Working in a panel box is extremely dangerous and should only be attempted by a certified electrician.

• There is always a risk of electrical shock when working with electricity.

References

• Heimer Engineering: Circuit Breaker
• Mike Butler; Electrician, Ninety Six, South Carolina