Search results
Results from the WOW.Com Content Network
When commercial electric power was first introduced in the 1880s, it was used primarily for lighting. Other portable appliances (such as vacuum cleaners, electric fans, smoothing irons, and curling-tong heaters) were connected to light-bulb sockets. As early as 1885 a two-pin plug and wall socket format was available on the British market.
An electronic symbol is a pictogram used to represent various electrical and electronic devices or functions, such as wires, batteries, resistors, and transistors, in a schematic diagram of an electrical or electronic circuit. These symbols are largely standardized internationally today, but may vary from country to country, or engineering ...
BS 546, Two-pole and earthing-pin plugs, socket-outlets and socket-outlet adaptors for AC (50–60 Hz) circuits up to 250 V is an older British Standard for three-pin AC power plugs and sockets. Originally published in April 1934, it was updated by a 1950 edition which is still current, [1] with eight amendments up to 1999. BS 546 is also the ...
NEMA 1-15P (two-pole, no ground) and NEMA 5-15P (two-pole with ground pin) plugs are used on common domestic electrical equipment, and NEMA 5-15R is the standard 15-ampere electric receptacle (outlet) found in the United States, and under relevant national standards, in Canada (CSA C22.2 No. 42 [1]), Mexico (NMX-J-163-ANCE) and Japan (JIS C 8303).
IEC 60309 (formerly IEC 309 and CEE 17, also published by CENELEC as EN 60309) is a series of international standards from the International Electrotechnical Commission (IEC) for "plugs, socket-outlets and couplers for industrial purposes".
For example, a surface ceiling light is shown by one symbol, a recessed ceiling light has a different symbol, and a surface fluorescent light has another symbol. Each type of switch has a different symbol and so do the various outlets. There are symbols that show the location of smoke detectors, the doorbell chime, and thermostat.
The symbol connected to the dot (usually the symbol found to the right) denotes the polarity of the center/tip, whereas the symbol connected to the broken circle denotes the polarity of the barrel/ring. When a device or adapter is described simply as having "positive polarity" or "negative polarity", this denotes the polarity of the center/tip.
Each switch or means of operating a switch, for a socket-outlet shall be (a) as close as practicable to the socket-outlet, and (b) marked to indicate the socket-outlet(s) or the connected electrical equipment that it controls, with the exception that marking is not required where the socket-outlet controlled is obvious because of the location ...