What is a receptacle?

When you plug something into a conventional duplex receptacle (the type that receives two appliance plugs), and the device doesn't work, trouble shooting the problem is fairly simple. For large receptacles that run on 220 to 240 volts, such as ranges and dryers and air conditioners, call an electrician unless you're well-versed in electrical repairs and safety issues. Always check when installing if the appliance is rated from 15 to 50 amps, 240 volts, and 20 to 50 amps, 120/240 volts. They have two hot wires (red and black) and a separate grounding wire.

Receptacle basics
Conventional duplex receptacles have two places to plug in electrical cords or devices. Each of those two places includes one narrow slot, one wide slot, and a semicircular hole. The narrow slot is the "hot" side, connected to the black wire of the electrical system. The wide slot is the "neutral" side, connected to the white wire. And the semicircular hole is the ground, connected to a bare or green wire or the electrical system's ground. Many electrical plugs have one wide blade and one narrow blade (and, in some cases, a ground plug) that match the receptacle's slots to insure that the circuit is properly connected to the electrical device.

Wires may be attached to screws on each side of the receptacle or plugged into terminal holes in the back of the receptacle. Whether wires attached to screw terminals or are pushed into rear-mount terminals, the screw terminals on the sides of the receptacle are hot (charged) so don't touch them!