Adding a 20 amp, 240 volt circuit to your home is only slightly more involved than wiring a 120 volt circuit. Once you have installed the outlet, routed the proper 12-3 with ground NM (nonmetallic sheathed electrical cable) wire back to the breaker box, and snapped the correct 20-amp double pole breaker into the box, all that remains to do is connect the wire leads to their proper locations.
A 240 volt circuit is just like a 120 volt circuit, except that it has one additional (red) wire.
Things You'll Need
- Flat blade screwdriver
- Wire stripper
- Electrician's pliers
Switch off the main breaker.
Strip 1/2 inch of insulation from the ends of the white, black and red wires of the new circuit.
Locate the ground and neutral bus. It will be a metal strip with holes and screws in it, with bare and white wires connected to the holes. Locate two empty holes and loosen their corresponding screws with the screwdriver.
Insert the bare wire of the new circuit into one of the holes. Tighten the screw to secure it. Insert the white wire into the other hole, and tighten the screw to secure it.
Loosen both screw terminals in the new breaker. Insert the black wire into one terminal and tighten the screw to secure it. Insert the red wire into the other terminal and tighten the screw to secure it.
Fold the excess wire back into the box. Reinstall the panel cover.
Tips & Warnings
- Replace the panel cover before you switch the main breaker back on.
- Although it seems that you could insert both the white and bare wire into the same hole in the ground/neutral bus, doing this would not meet code and could result in increased danger of electrical shock.
- If this is to be an outdoor circuit, use UL or other cable rated for outdoor use.
- "Wiring a House"; Rex Cauldwell; 2002
How to Wire a Garage Woodshop
If you are wiring a garage woodshop, you need to decide how many circuits you will need and how you will supply...
How to Wire a 240 Volt 40 Amp Circuit
Most home circuits carry 120 volts, although appliances such as ovens and electric dryers require more power. Wiring a 240-volt circuit is...
How to Wire a 2-Pole 60 Amp Breaker
In the United States, electrical outlets have a designated energy level of 120 volts. However, the maximum possible voltage is 240 volts....
How to Wire a Double 40 Amp Breaker for a Home A/C Unit
It takes no special skills to install a new breaker into your home’s main electrical panel. Circuit breakers are not interchangeable or...
How to Install a 110-Volt 20-Amp Circuit Breaker
A 20-amp circuit breaker requires a wire that is larger than the normal 15-amp circuit breaker wire used in most houses. For...
How to Wire a 220 Volt 20 Amp Outlet
There are three things you must take into consideration when wiring a 220-volt outlet. First, 220-volt circuits do not use neutrals. Second,...
How to Wire a 20-Amp 250-Volt Outlet
Powering heavy appliances such as air conditioners usually requires a 20-amp 250-volt outlet. These outlets typically have different configurations than the standard...
Can You Switch a 15 Amp Circuit Breaker to a 20 Amp?
You walk into your bedroom, turn on the lights, and then plug in the vacuum. Suddenly all the lights go out. The...