![]() ![]() For example, the current-carrying capacity of a cable clipped direct to a surface is generally higher than that of the same cable enclosed in conduit or trunking. The installation method affects the rate of heat dissipation and hence the current-carrying capacity of a cable. Table 4A2 of Appendix 4 lists the different installation methods and their related reference method codes recognised by BS 7671. The current to be carried by a conductor for sustained periods during normal operation shouldn’t result in the appropriate temperature limit specified in Table 52.1 of BS 7671 being exceeded (523.1). The cross-sectional area (csa) of live conductors must not be less than the minimum sizes stated in the relevant part of BS 7671, such as Table 52.3 (general), Table 55.2 (auxiliary circuits) and, where applicable, in various sections in Part 7 covering special installations/locations (524.1). Correcting the current-carrying capacity of a cable for ambient conditions
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