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Comparison of SWG (red), AWG (blue) and IEC 60228 (black) wire gauge sizes from 0.03 to 200 mm² to scale on a 1 mm grid – in the SVG file, hover over a size to highlight it. In engineering applications, it is often most convenient to describe a wire in terms of its cross-section area, rather than its diameter, because the cross section is directly proportional to its strength and weight ...
Depending on the type of insulating material, common maximum allowable temperatures at the surface of the conductor are 60, 75, and 90 °C, often with an ambient air temperature of 30 °C. In the United States , 105 °C is allowed with ambient of 40 °C, for larger power cables, especially those operating at more than 2 kV.
A wire or cable has a voltage (to neutral) rating and a maximum conductor surface temperature rating. The amount of current a cable or wire can safely carry depends on the installation conditions. The international standard wire sizes are given in the IEC 60228 standard of the International Electrotechnical Commission.
In both those instances the white wire should be identified as being hot, usually with black tape inside junction boxes. The neutral wire is identified by gray or white insulated wire, perhaps using stripes or markings. With lamp cord wire the ribbed wire is the neutral, and the smooth wire is the hot. NEC 2008 400.22(f) allows surface marking ...
The service factor is typically in the 1.15-1.4 range, with the figure being lower for higher-power motors. For every hour of operation at the service-factor-adjusted power rating, a motor loses two to three hours of life at nominal power, i.e. its service life is reduced to less than half for continued operation at this level.
Wire gauges may be broadly divided into two groups, the empirical and the geometric. The first includes all the older gauge measurements, notably the Birmingham gauge (B.W.G. or Stubs) and the Lancashire. The origin of the B.W.G. is obscure. The numbers of wire were in common use earlier than 1735 when the measurements were officially defined. [1]
Older solid aluminum wire also had some problems with a property called creep, which results in the wire permanently deforming or relaxing over time under load. Aluminum wire used before the mid-1970s had a somewhat higher rate of creep, but a more significant issue was that the same high price of copper driving the use of aluminum wire led to ...
As many modern types of electrical accessories (e.g., home automation control elements from non-UK manufacturers) are not available in BS 4662 format, other standard mounting boxes are increasingly used as well, such as those defined in DIN 49073-1 (60 mm diameter, 45 mm deep, fixing screws 60 mm apart) or, less commonly in the UK, ANSI/NEMA OS-1.