A simple approach to conductor sizing and prolonging the thermal life of electrical cables below 1000V for industrial and commercial applications

Electrical conductors are, arguably, the most important component of industrial and commercial electrical distribution systems as electrical conductors, or just conductors, facilitate the interconnections between a source (e.g., generator, renewable energy source, Utility, electrical distribution panel, etc.) and load (e.g., wall outlet, control panel, motor, etc.). However, for typical electrical system installations, electrical conductors are rarely given the attention deserved. In general, the selection of conductors becomes a fine balancing act of meeting the minimum National Electric Code (NFPA 70) requirements for minimum ampacity and the economics of choosing aluminum vs. copper. This can lead to conditions where conductors are not adequately sized for the conditions they are exposed to, which can result in premature failure of cable insulation. This paper presents a simple approach to proper conductor selection, with an emphasis on maximizing the thermal life of cable insulation.