What Is Inside An Electrical Outlet

Warning: Before you do any repairs on a receptacle, turn off the power at the breaker box.

Receptacle

Replace if any part of face is broken or it doesn’t grip plug’s prongs firmly. Make sure amp rating embossed on face of receptacle doesn’t exceed amp rating printed on cable.

Contact Openings

Different shapes ensure appropriate plug prongs are matched to hot, neutral, and grounding wires.

Terminal Screws

Safest points of wire connection. (Push-in terminals, or “backstabbers,” on back of receptacle are not as secure.) White wire always goes to one silver screw (it doesn’t matter which one), and black wire to one brass. Swapped wires or loose screws will cause shorts or shocks.

Grounding Screw

Connects to bare grounding wire to help prevent electric shocks.

Mounting Strap

Holds receptacle flush with outside of box.

Nonmetallic Cable

Also known by trade name Romex. Plastic jacket contains black (hot), white (neutral), and bare copper (grounding) wires that connect to circuit-breaker panel.

Steel Outlet Boxes and Armored Cable

In older homes and some cities, steel outlet boxes and armored cable are the rule. In this case, the receptacle is grounded to the box, which in turn is grounded by the cable’s metal sheath. Wrapping electrical tape over the terminal screws prevents them from touching the box and short-circuiting.