User Groups

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Houston User Group Meeting, March 2016

Cable Thermal Analysis using ETAP

Cable derating analysis is an important part of power system design and analysis. For new system, ETAP can be used to determine the proper size of cables to carry the specified loads. When performing a cable thermal analysis of an existing system, the Underground Raceway Systems module can handle multi-raceway and direct buried conduits and considers the effect of heat generated by neighboring cables and external heat sources.


  • Compute the effect of duct banks or direct buried conduits based on cable steady-state and transient temperatures.
  • Cable ampacity calculation and cable sizing are based on the NEC accepted Neher-McGrath method
  • Model direct-buried cable systems surrounded with soil as well as cables in conduits surrounded by a raceway (e.g. concrete) with different thermal resistivity than the surrounding soil
  • Fully complies with latest IEC 60287 temperature calculation standards
  • Graphical Alert Viewer. Reports critical & marginal cable temperatures and overload condition

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