How to Fix Ungrounded Outlets

Posted by Anna Hill | Jan 30, 2014
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Photo: Check All Home Inspection/Flickr

If you’ve got ungrounded two-prong outlets in your home, apartment, or fixer-upper building, you will want to repair them so that they are compatible with safer and more modern three-pronged outlets. Properly wiring and repairing outlets to comply with modern electrical systems will not only ensure that electrical fires don’t start and cause problems for your home or office, but that three-pronged plugs (which are much safer than older two-pronged plugs) can do their job effectively. Current three-pronged plugs have a third plug (called a “grounding pin”) so that electricity that could otherwise overload the two top plugs does not do that, and therefore inhibits the risk of electrical fires or dangerous electric shocks, which were an unfortunate risk with two-pronged outlets.

Before you begin, plug a voltage tester (a device that measures the flow of electrical current when inserted into an outlet) into opposite prongs above and below; the instruction manual included with the tester will most likely include a diagram of this. If the tester lights up, the outlet is still working. Then, make sure to turn off the electricity that may be running; this way, you will avoid an obvious safety hazard.

Remove the two-pronged outlet cover(s) from the wall, using a screwdriver. Inside of the metal box that was attached to the outlet cover, you will see a white-coated wire (neutral wire) and a black-coated wire (hot wire); these are usually attached to an armored cable in the back of the box, and to the outlet that was just unscrewed. As you disconnect these from the box, do not touch them together. Make sure that they are relatively straight.

To install a three-pronged outlet after removing the old outlet, use the terminals that are meant for the white and black wires to connect the existing wires; these will be labeled on the outside of the outlet, usually with LOAD and LINE, one for each color. Connect the white/neutral wires to the silver screws in the outlet, and connect the black/hot wires to the brass screws. A word of caution here: DO NOT touch the “hot” and “neutral” sides of the outlet’s inner workings at the same time while you are re-wiring it! Doing so could lead to electrical shock.

After you’ve connected these wires to the new outlet, connect the bare ground wire inside of the box to a green screw (available at any hardware store) in order to finish grounding the outlet. The green screw will fit into a threaded hole at the rear of the metal box; tighten the screw and attach the bare ground wire to it with a screwdriver. Screw in your now-completed outlet to the wall.

To test your newly grounded outlet, turn the power back on, then utilize a circuit tester to make sure that your new outlet is safely working. With these simple steps, you can now use appliances of all sorts without having to worry about fire, electrical shock or other safety concerns.

Anna Hill writes for

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