At your service panel there are two bus bars, each is 120 volts. When you pick up a wire from each side, you have 240 volts. There is probably a Black, Red (‘Hot’ Lines), White (Neutral) and Bare wire (Ground). Black and Red make 240 volts. One Black and the White make 120V and one Red and White make another 120V.
If you have 3 wires, 2 Lines and 1 Neutral: At the panel, verify that one conductor is terminated to the neutral bar. This ensures you have a Neutral. Assuming you have a Neutral, remove the 2 pole breaker and install 2 single pole breakers, terminating one ‘Hot’ conductor to each breaker. Don’t forget to share the Neutral between both circuits. Terminate one Line conductor and one Neutral to each receptacle.
For installation a 20A outlet, you will need:
- Cover plate
- 12 gauge insulated copper wire
- Two 20A single pole breakers
- Turn the existing 220V breaker off at the main service panel. Use a test lamp or meter to check for ‘Power Off` before proceeding.
- Turn the main power off at the main service panel.
- Loosen and remove the screws in the four corners on the service panel door, and set the panel aside for later reassembly.
- Locate the existing 220V breaker and disconnect the two heavy (‘Hot’) wires from the poles.
- Put wirenuts on the exposed ends.
- Remove the old two pole breaker, and install your two new single pole breakers. Turn them ‘Off’.
- Connect the Black (‘Hot’) wire to the single screw on the breaker. Connect the Red (‘Hot’) wire to other one of your new breakers.
- Replace the service panel cover, insert a screw into each corner and tighten them down, securing the cover in place.
- At the outlet box, remove the old outlet, put a wirenut on end of the ‘Line’ wire you’re not using, and tuck it into the box.
- Use a wirenut to connect the ‘Line’ wire you will use to a short length of insulated 12 gauge wire, and connect this to the ‘Line’ side of your receptacle.
- Connect the White wire, and Ground wire, to the receptacle in a like manner, install the receptacle and plate. (Connect the Black or Red wire to the brass screw, the White wire to the silver screw, and the Bare wire to the green screw.).
- Push the wiring into the box. Insert a screw into the bottom and top holes and tighten the outlet down to the outlet box. Attach the cover plate over the outlet and tighten the screws down.
Turn the main power switch back on and ensure that the new 110V breaker is in the ‘On’ position. Plug in a light to the outlet and test for power.
Do not put in a breaker with an ampacity that is more than the wire is rated to handle (for copper wire):
- 10 gauge wire – a max breaker of 30A
- 12 gauge wire – a max breaker of 20A
- 14 gauge wire – a max breaker of 15A
If you are not absolutely positive on how to do this, please have the work done by a licensed electrician.