How to Add Breakers to an Existing Breaker Panel

If you want to add a new circuit breaker to your existing service panel, you first need to be sure that building codes allow you to add a new line in your home. Once you are in the clear, double-check that the power supply is turned off. If you don't, this relatively routine procedure could injure or kill you.

• 1

  Turn off the power by switching off the main breaker. Remove the cover of the panel and use a voltage tester to ensure the power is truly off. Test to make sure the entire panel is off by pressing one probe to the neutral bus bar and the other to the bus that has the breakers attached to it. If the tester does not read anything, the power is properly shut off.

• 2

  Take out the knockouts to make room for the new breaker. If you are installing a single pole breaker, it will need one space inside the box; double pole breakers require two spaces. Use an insulated hammer and punch out one of the circular holes in the side of the box to make room for the new cable.

• 3

  Install the proper cable connector and snake enough wire through the circular knockout hole and inside the box so that it can reach its point of connection.

• 4

  Strip the outside of the wire directly at the point where it enters the inside of the box. You will expose different colored wires that will need to be attached to their appropriate bus bar.

• 5

  Attach the ground wire to the ground bus bar. Attach the white wire to the neutral bus bar and the black wire to the breaker. If you have a three-wire cable plus ground, the red and black wires are connected to the breaker and the white wire is connected to the neutral bar.

• 6

  Install the breaker in its place by pushing the device into the slot until the spring clips lock it into place.