How to Wire an AC Disconnect

What You'll Need
AC Disconnect Switch
Wire Cutters
Electrician's Tape
Electrical Voltage Meter

An AC disconnect switch is used to help shut down the AC power in your home in the event of a fire, flood, or another catastrophe. This switch is typically located outside the home or in a location that can be accessed quickly in an event when the power must be shut down. The process for wiring an AC disconnect switch to your home requires some knowledge of wiring.

Step 1 - Turn the Main Power Off

Before you begin the process of installing and wiring an AC disconnect switch, you need to shut off the main power to your home. To do this locate the main circuit box and place the main circuit breaker in the off position. Allow some time to pass before you begin the work of wiring the AC disconnect to the home.

Step 2 - Mount the Disconnect Switch

Locate the wires that feed into the main power box from the outside of your home. Once you locate the wires, drill holes near them in order to mount the disconnect switch. You want to mount the disconnect switch as close as you can to the wiring in order to connect the switch after it has been properly mounted.

Step 3 - Identify Wires for the Disconnect Switch

The switch will have either three or four wires depending on the voltage of the circuit that you are connecting the AC disconnect switch to. If the circuit is a 110-volt circuit, use an AC disconnect switch with three wires. There will be a neutral white colored wire, a green colored ground wire (which may also be bare copper) and a black (or red) hot wire. If the circuit is a 220-volt circuit, the AC disconnect switch that you will use will have four wires (an additional hot wire that is black or red in color).

Step 4 - Attach the Ground Wire

Attach the ground wire (in the case that it does not need to be cut off) to the ground wire in the circuit that you are connecting the AC disconnect switch to. The ground wire will be the green or bare copper colored wire in the AC disconnect switch, and should match the color of the wire it is being attached to. Use wiring caps and electrician's tape to seal the connection.

Step 5 - Cut Hot Wires

Connect the hot wires to their corresponding hot wire for the AC disconnect switch. Make sure that you use caps and electrician's tape to seal the wires. Once the wires are connected and the switch has been secured to the wall, return the main power and test the switch to make sure that it is working properly.