Electrical Outlets

Electrical outlets are receptacles for the transmission of electricity into home appliances, designed to receive the insertion of a brass- or tin-plated plug. First patented in the early twentieth century, outlets have gradually evolved into their modern design, which is maximized for both safety and efficiency.


Electrical Outlet Overview

Electrical outlets are connected to wires in walls which run to the central circuit breaker of the home. Most outlets in the United States and Canada today are duplex receptacles, providing six holes for two plugs. A plug itself consists of three points:

  • A live, or "hot" point
  • A neutral point
  • A grounding point.

The live point is shorter than the neutral point and the semi-cylindrical grounding point is much smaller than either. This three-point system is designed to safely alternate incoming current and to direct dangerous current, such as what may be produced in the case of a leak, harmlessly into the earth.

Older Electrical Outlets

Older outlets do not possess the grounding point, and can only be connected to a three-point plug by means of an adapter, a three-point socket attached to a two-point plug. Such adapters should not be used unless the outlet itself is properly grounded. This can be determined by inserting the probes of a special outlet tester into the socket, but it is often advisable simply to replace older outlets with those which can process the three-point setup.

Replacing Electrical Outlets

Replacement is a fairly simple process, consisting of:

  1. Shutting off the power at the service panel
  2. Unscrewing the old outlet
  3. Noting the placements of the three colored wires
  4. Hooking them in the same positions to the new outlet
  5. Wrapping the terminals of these wires in electric tape for protection
  6. Screwing the new outlet back into place.

Electrical Outlets in the United States

Standard electrical outlets in the United States are designed to process a load of 15 amps. Some are designed to handle 20 amps, and these are recognizable by their irregularly shaped neutral slots, which resemble the letter T. They should only be used with circuits meant to handle such currents.

Electrical Outlets in Other Countries

Though uniform within most of North America, electrical outlets vary widely over most of the world, the result of poor standardization during the infancy of electrical design. Varieties of electrical outlets are categorized by letters and proceed as high as the letter M, with each class of outlet possessing varying numbers, shapes, and layouts of receiving slots.

Foreign appliances or outlets can usually be made use of through special adapter kits. One should never attempt to insert a plug into a non-compatible outlet, and one should absolutely never modify a plug in any way, such as by removing the grounding point to fit it into a two-point outlet.