TEMPERATURE DISTRIBUTIONS AROUND BURIED CABLES

Methods for analysis of temperature distributions around buried power cables are reviewed. None accurately models the true geometric conditions or properties or enables prediction of the time-dependence of temperature change. A finite element computer program HEAT was used to study both transient and steady-state temperature distributions both within the cable trench backfill and the surrounding soil. Allowable heat input rates to limit cable sheath temperature to 60°C and 90°C were determined and the influences of varying weather and soil property conditions were studied. The thermal resistivity of the trench backfill has a dominating influence, and allowable heat input increases significantly with increase in cable size. Incoming solar radiation on a calm day can have a severe limiting effect on allowable heat input from the cable. Copyright © 1979 by The Institute of Electrical and Electronics Engineers, Inc.