For a number of buried circuits that is comparatively easy train to find out the mutual heating since conduction of warmth flux by means of the soil is the one mechanism of warmth switch and so the superposition theorem will be assumed in line with IEC 60287-2-1.
For a number of circuits in air the mutual heating results are extra sophisticated since they encompass each convection and radiation warmth switch mechanisms. For teams of circuits in air of the identical cable sort, with the identical losses (i.e. carrying the identical currents) and neglecting dielectric losses (for XLPE insulated cables dielectric losses can solely be uncared for beneath 63.5 kV) we are able to check with Customary IEC 60287-2-2 for steerage.
Customary IEC 60287-2-2 supplies 12 customary (fastened) configurations for calculation of present score of teams of cables (of the identical cable sort) in air. These configurations are offered within the In Teams module of Cable HV™ Software program (picture beneath). The explanation there are solely fastened configurations accessible is as a result of the tactic on this customary was developed based mostly on bodily experiments which was restricted to a examine of solely these 12 configurations.