Installation of a 220-Volt Breaker

Turn off the power supply to the work area. Switching the "Main" breaker to the "Off" position terminates the electricity to your house. To be certain that all the power is off, position every breaker in the service panel to the "Off" position or ask the electric company to stop service.

Use the hot wire tester to verify that no current is flowing through the "Main" breaker.

Use a flat-head screwdriver to pry off covers from two empty adjacent slots in the service panel. These are where you will install the new 220-volt breaker. It is twice as big as the 110-volt, so you need two empty slots for installation. An empty breaker slot is called a "knockout" in the trade

Connect the hot wires from the knockouts to the 220-volt breaker using a Phillips screwdriver. You will need to connect two pairs of hot wires, one pair per knockout. A pair of hot wires consists of one red and one black wire that are preinstalled in the knockout. To determine which wire connects to the corresponding terminal on the breaker, follow the manufacturer's instructions on the packaging.

Hook the two white neutral wires, one from each knockout, to the neutral terminal (neutral bus) bolts in the service panel. You can connect multiple neutral wires to a single neutral terminal.

Snap the 220-volt breaker into the knockouts.

Verify that all your wire connections are secure and correct. Turn on the power to test your 220-volt circuit.