What Is A Polarized Receptacle

The plug is a male connector with protruding pins that match the openings and female contacts in a socket.

What is a polarized receptacle. A polarized plug is easily distinguishable from other plugs because the blade on one side is wider than the other. Both the polarized and non polarized 2 prong household plugs will fit into your 3 prong standard household outlet receptacle. If the receptacle is housed in a metal box that is connected to a metal conduit rigid or flexible the receptacle may be grounded through the box and conduit but again it cannot ground a plugged in device. Although polarized outlets and plugs were introduced in the 1880s they were not popular at first and did not become standard until the mid 20th century.

The earliest national electric code nec that we can find that references polarized receptacles is the 1962 edition which required outlets to be both grounding 3 prong and polarized. At the end of any appliance electrical cord there is a plug with two or three prongs blades designed to fit into standard wall outlet receptacles. When there are three prongs these are known as grounded plugs and they are designed to fit into wall outlets so the round bottom prong fits into the ground slot on the outlet thereby connecting the appliance s wiring to the house s grounding. Consequently a polarized plug can only be inserted into an electrical outlet one.

If a polarized receptacle is wired correctly the narrow slot connects to the hot wire delivering power to the receptacle and the wide slot connects to the neutral wire carrying power back to the service panel. The standard residential outlet in north american homes is the nema 1 15r which accepts both polarized and unpolarized plugs. A plug is the movable connector attached to an electrically operated device and the socket is fixed on equipment or a building structure and connected to an energised electrical circuit. An appliance with a polarized power cord has a nema 1 15p plug with prongs that match the outlet.

The simplest way to tell if your receptacle electrical outlet is polarized is if you are able to plug in a three prong plug nema 1 15 ground type b or if a two prong plug nema 1 15 ungrounded type a can only fit with the larger prong on the left. An electrical plug is designed to complete an electrical circuit from your home s electrical panel to your electronic device and back. To learn more about plugs and receptacles read our preview post here. The hot pin on a polarized plug is the smaller of the two pins and is connected to the black wire on the inside of your plug and cable.

The narrower prong is the hot lead and the switch to the appliance is placed in that lead gauranteeing that no voltage will reach the appliance when it is switched off. These receptacles and plugs are polarized.