Wire Size for an Air Conditioner

Gauge

• Wire size or gauge is measured by the American Wire Gauge (AWG) number. The smaller the AWG number, the more volts and amps the wire can handle. Locate the AWG number on your air conditioner’s nameplate, which is typically next to the electrical connection. Most individual 220-volt air conditioner units require either a 12-gauge 20 amp or 10-gauge 30 amp wire. You can use a thicker wire with a lower AWG number than the one required, but you should never use a wire with a higher AWG number.

Length

• Ideally, your air conditioning unit should be placed near an electrical outlet. The wire should be long enough to reach the outlet without having to stretch or bend; this can damage the wire over time and could present a fire hazard. Choose a wire that is long enough to connect the unit to the wall outlet and leave a little slack. If you must use a long wire, use one with a lower AWG number than the one listed on the nameplate to compensate.

Material

• Copper is the preferred material for air conditioner electrical wiring. Avoid using an aluminum wire or copper-coated aluminum wire. If you must use an aluminum wire, hire an electrician to perform the recommended special termination techniques. Use the stranded, not solid, type of wire.

Precautions

• When connecting an air conditioner, use common sense and follow certain precautions to avoid injury, damage to the appliance and property damage. Avoid hooking up an air conditioner near a sink, bathtub or other water source. Enclose the wire in a conduit to protect it, particularly if you’re using a longer wire. Turn your air conditioner off when not in use to avoid burning out the motor.