Black, white, green, red, blue, orange, brown and gray, insulated wires outside jacket color is usually refers to its own meaning. Therefore, when playing with new lighting, in addition to the breakers off, you should also make sure that you then have to encounter each colored wires have what meaning.
US electricity residents did not begin color coding system, not even a standard for proper use. In 1879, when Edison first introduced shortly lights, the insurance industry began to release some safety guidelines. The first set of official guidelines appeared in 1881, including addressing capacity, insulation and installation. But no cable color classification.
In 1882, the National Board Fire Underwriters (NBFU) has been adopted early safety regulations. In 1893, the National Insurance Institute began trying to put the power of each state different electrical devices to unify and standardize the criteria proposed national coding standards for the construction and wiring of the lamp power supply unit.
First National Electrical Code (NEC) is NBFU proposed in 1897, it also ignores the cable color standardization issues. Later, in 1928, NEC revised update in which there is a requirement to establish ground color specification, which is later white or natural gray, also prohibits those colors used in the live line and the neutral line.
Further color coding are NEC launched in 1937 a new version, with color-coded to use the line and the line "multi-branch circuit" and provides for three branches of the circuit to use black, red and white. More branches can add another color, such as yellow and blue.
In 1953, NEC changed the color of the ground wire, turn green or bare wire. Green is also prohibited for a circuit line (such as live and neutral).
1971 edition of the NEC color coded to run up more branches, although white, natural gray, green, and yellow and green stripes remain, these colors are also banned for the ground wire. The path specification lost rigid wire color coding requirements, because not enough color to make the system voltage circuit distinction.
Now the United States, the grounding wire is green, yellow stripes or bare wire, the neutral wire should be white or gray, the circuit lines may be black, red, blue, yellow, orange or yellow, depending what color depending on the voltage.
These color standard of the United States, other countries, codes are not the same (very similar to Canada and the United States). For example, Australia and New Zealand and the United States ground wire of the same color, they are neutral blue or black. Moreover, the live line can be any color except the ground wire and neutral wire. Red and brown colors are recommended single-phase line, red, white and blue multiphase flow is a live wire recommended color.
New Britain (2004) changed the International Electrotechnical Commission (EC) to comply with the system. Their ground color (yellow and green stripes) remains unchanged from the original neutral color black to blue. Similarly, the previous single-phase wire is red now turned brown. In addition, the British multi-phase line markers and coloring also changed: L1 from red to brown, L2 from yellow to black, L3 dimmed by the blue.
(Translation: via Today I Found Out)
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