A single receptacle, also called a single outlet or single electrical socket, is one which receives only one electrical plug. It differs from a standard residential receptacle, which usually has room for two plugs. Single receptacles are often placed in commercial and industrial settings where heavy machinery and equipment is used. They are also common in residential construction where major appliances, such as refrigerators, stoves, washers, dryers and dishwashers, are installed.
The appearance of a single receptacle frequently differs from standard electrical receptacles. Though single receptacles that look like common receptacles are available, most accept plugs with larger prongs, include a hole for the ground wire, and may include a locking mechanism that prevents machinery from being accidentally unplugged. The overall size of the receptacle may be larger than a standard receptacle in order to accommodate appliance and heavy machinery plugs, which are often more substantial than those on smaller household equipment, like toasters or printers. A single receptacle is usually round and requires a special wall-plate when flush-mounted in a wall.
Another benefit of single receptacles is that the receptacle itself can be wired for more amperage. Since they are more substantial, and because no other item plugs into the same receptacle, they can power heavy equipment — such as industrial compressors, assembly machines, and conveyor belts — that require more energy to run than the typical household appliance.
Machinery or equipment requiring a dedicated circuit is often plugged into a single receptacle. This eliminates the possibility of another item being plugged into the same circuit and either drawing needed power away from the primary equipment or overloading the circuit. Overloaded circuits can flip breakers, blow fuses, and even cause minor fires.
In other cases, maintaining the exclusivity of circuitry is even more critical. In hospital rooms, particularly those in critical care units or operating rooms, monitoring equipment and life-sustaining machines are frequently plugged into a special single receptacle that allows the plug to be locked into place. These special outlets are also generally wired to alarms that alert the nursing station should important equipment somehow become unplugged.
Due to their ability to supply greater power and ensure circuit exclusivity, single receptacles are often specified by construction codes in certain situations. Low-duty commercial and residential single outlets are usually available for purchase at home improvement stores and hardware stores. Heavy-duty models may need to be special-ordered or purchased online through industrial construction suppliers.