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Aluminium conductor steel-reinforced cable (ACSR) is a type of high-capacity, high-strength stranded conductor typically used in overhead power lines. The outer strands are high-purity aluminium , chosen for its good conductivity, low weight, low cost, resistance to corrosion and decent mechanical stress resistance.
The equation in section 310-15(C) of the National Electrical Code, called the Neher–McGrath equation (NM), may be used to estimate the effective ampacity of a cable: [3] = (+) (+), In the equation, T c {\textstyle T_{c}} is normally the limiting conductor temperature derived from the insulation or tensile strength limitations.
Several kinds of ratings may be made available, including: real-time, indicating ampacity immediately available, without time limits should conditions remain identical; emergency ratings for a limited duration; and same-day and day-ahead forecasts. DLR computations deal with "near real-time" data, updated about every five minutes.
For example, the United States National Electrical Code, Table 310.15(B)(16), specifies that up to three 8 AWG copper wires having a common insulating material (THWN) in a raceway, cable, or direct burial has an ampacity of 50 A when the ambient air is 30 °C, the conductor surface temperature allowed to be 75 °C. A single insulated conductor ...
Its light weight and softness result in roughly 30% greater conductivity than an equivalent ACSR conductor, allowing 14% more current to be carried at equal temperature. For example, 1.107 in (28.1 mm) diameter ACCC "Drake" conductor at 75 °C has an AC resistance of 106 mΩ/mile, [ 7 ] while equivalent ACSR conductor has an AC resistance of ...
Aids to electrical calculation started with DC network calculating boards and AC network analyzers, which reached a high degree of development by the middle of the 20th century. Large scale digital computers became powerful enough to overtake the previous analog model systems.
Cutaway diagram of a shielded multicore cable with four cores each with three individual conductors. A multicore cable is a type of electrical cable that combines multiple signals or power feeds into a single jacketed cable. [1] The term is normally only used in relation to a cable that has more cores than commonly encountered. [2]
Circuit integrity fireproofing of cable trays using calcium silicate board system Circuit integrity fireproofing of cable trays Fire-resistant cables MI cables fastened into junction box that has not been fireproofed. Circuit integrity describes the extent of a fire's effect on an electrical circuit's operation. It is a form of fire-resistance ...