How to Change an Electrical Outlet to Three Prong

Ground-fault circuit interrupter outlets should be placed in bathrooms and kitchens.

Change your old two-prong electrical outlets to safer three-prong outlets, without extensive rewiring, if your outlet box has already been grounded. Many older homes in the United States have these older style of electrical receptacles, connected only to two-wire cables and no ground wires included to protect electrical devices or the people using them. Most of these older outlet boxes are already grounded, so you can update to new, safer outlets yourself, if you follow general electrical safety rules.

Things You'll Need

• Circuit tester
• Screwdriver

Instructions

1. Test the outlet to see if it is grounded, using a circuit tester. Place one prong of the tester into the shortest receptacle slot and touch the other prong to the screw that holds on the cover plate. Your tester will light up if the outlet is grounded.

2. Locate your breaker or fuse box and turn the power off to the receptacle you are replacing.

3. Use your screwdriver to remove the screws from the cover plate, then place it to the side.

4. Unscrew the old receptacle from its box and detach the wires. Remove the old receptacle and place it out of the way.

5. Place the new receptacle in and attach the wires. The black wire is the hot wire, which is attached to the brass terminal. Attach the white neutral wire to the silver terminal.

6. Screw the green ground screw into the threaded hole at back of the box. Attach one end of a pigtail to this screw and tighten it up with your screwdriver.

7. Hook the other end of the pigtail to the green grounding terminal on the new receptacle.

8. Turn your power back on and test the outlet with your circuit tester.

Tips & Warnings

• Always ensure that the power is cut off to the outlet before you start removing the old one.

• Take your time and complete each step in proper order.

References

• This Old House: Replacing Two-Prong Receptacles