Cable crossings-derating considerations. II. Example of derivationof derating curves

摘要

For pt.I see ibid., vol.14, no.3, p.705-14 (1999). Cables crossingnother heat sources either perpendicularly or at oblique angles willnexperience a rise in conductor temperature which should result innampacity derating. In the first part of the paper a mathematical modelnfor calculation of derating factors was presented. In this paper, anpractical numerical example is considered with a 138 kV pipe-type cablencrossing a 10 kV distribution circuit. The numerical analysis presentednconfirms experimental findings reported in the literature that the cablencrossing may elevate conductor temperature by as much as 20°C