Search results
Results from the WOW.Com Content Network
The Electrical Safety Foundation International has stated: "Never remove the ground pin (the third prong) to make a three-prong plug fit a two-prong outlet". [18] In addition to the dangers of breaking a ground connection, removing the ground pin to make it fit a 1-15R receptacle or extension cord , may result in the live–neutral polarity ...
Three-prong plugs do not fit into the older, two-prong receptacles. [7] When used as intended, the ground pin of the 3-wire receptacle is to be connected to a grounded cover screw, or to an external ground. In 1969, Underwriters Laboratories mandated three-prong plugs on major appliances for safety. [7]
A receptacle tester for North American wiring. An electrical outlet tester, receptacle tester, or socket tester is a small device containing a 3-prong power plug and three indicator lights, used for quickly detecting some types of incorrectly-wired electrical wall outlets or campsite supplies.
AC power plugs are also commonly circular, for example, Schuko plugs and IEC 60309. NMEA 2000 cabling using M12 connectors. The M12 connector, specified in IEC 61076-2-101, is a circular electrical plug/receptacle pair with 12mm OD mating threads, used in NMEA 2000, DeviceNet, IO-Link, some kinds of Industrial Ethernet, etc. [16] [17]
During the first 50 years of commercial use of electric power, standards developed rapidly based on growing experience. Technical, safety, and economic factors influenced the development of all wiring devices and numerous varieties were invented. After the two-prong electric plug was introduced in the 1920s, the three-pin outlet was developed.
The socket has a circular recess with two round holes and two earthing clips that engage before live pin contact is made. The pins are 4.8 by 19 mm (0.189 by 0.748 in). The Schuko system is unpolarised, allowing live and neutral to be reversed. The socket accepts Europlugs and CEE 7/17 plugs and also includes CEE 7/7. It is rated at 16 A.
Two pin sizes are standard in the jacks for this size plug body, 2.1 mm (0.083 in) and 2.5 mm (0.098 in), and the plugs should match. If the size is not known, it is difficult to distinguish by eye or measurement between the 2.1mm and 2.5mm ID plugs; some suppliers suggest simple methods.
Hence, a 10 A plug will fit into all of the five types of socket outlets, a 15 A plug will fit into all except a 10 A (and so on) while a 32 A plug will fit only into a 32 A socket outlet. In general, only 10 A and 15 A socket outlets are likely to be encountered in domestic or commercial installations.