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How to Connect Two Ground Wires to an Outlet

William Pippin

When wiring electrical outlets, electricians run the wires from one outlet to the next on the circuit. This generally leaves two sets of wires in most of the electrical boxes. Receptacles, or outlets, have two connection screws for both the white neutral wires and the black hot wires. There is only one green ground screw connection on an outlet. The two ground wires must be wire-nutted together along with another 6-inch length of green or bare ground wire known as a pigtail.

A grounded electrical outlet has three holes to provide a ground connection for three-prong plugged devices.
  1. Turn off the breaker controlling the outlet you're working on.

  2. Set your voltage tester to AC volts at its highest setting. Insert the red lead from the tester into the small slot on the outlet. Insert the black lead from the tester into the larger slotted hole in the same outlet.

  3. Check your voltage tester for voltage. If any voltage shows on the tester, the correct breaker is not turned off. Be sure that the right breaker is off and the outlet has no power before working on it.

  4. Remove the cover from the outlet with your straight screwdriver. Remove the two screws that hold the outlet into the electrical box. Pull the outlet out of the box so that all of the connection screws are visible.

  5. Loosen all of the screws on the outlet that are holding the wires. Pull the wires from the outlet.

  6. Curl the ends of the two white and two black wires. Wrap the white wires around the silver connection screws on the outlet with the open side of each curl on the right and tighten the screws. Wrap the black curled ends around the brass connection screws with the open side of each curl on the right and tighten the screws.

  7. Cut a 6-inch piece of bare No. 12 wire to be used as a pigtail. Cut the two ground wires in the electrical box to the same length, leaving at least 6 inches of each wire inside of the box to comply with National Electrical Code 300.14 concerning wire length in boxes.

  8. Hold the 6-inch pigtail alongside the other two ground wires with all of the wire ends even. Twist all three wires together in a clockwise direction with your pliers. Twist a wire nut firmly onto the end of the twisted ground wires.

  9. Put a curl in the end of the pigtailed piece of ground wire. Hook the curl around the green ground screw with the open side of the curl on the right. Tighten the ground screw securely with your straight screwdriver.

  10. Push the ground wires and wire nut into the back of the electrical box. Push the wires and outlet into the box and install the two screws that hold the outlet in. Check that the bare ground wires are not touching any of the screws on the sides of the outlet and install the cover.

  11. Turn the breaker back on.