The National Electrical Manufacturers Association (NEMA) has published ANSI/NEMA WC 51/ICEA P-54-440, “Ampacities of Cables Installed in Cable Trays”. The standard was produced by Insulated Cable Engineers Association (ICEA) Energy Division Working Group 440, and was last revised in 2003.

WC 51/P-54-440 provides ampacity ratings for 600V to 15,000V solid
dielectric cables installed in cable trays, tabulated for single
conductor cables, triplexed assemblies of single-conductor cables, and
three-conductor cables incorporating an overall jacket.

The revision includes corrected values in Table 5-4 and editorial
changes for clarity throughout. As in the previous edition, correction
factors are provided to adjust the tabulated values for ambient and
operating temperatures, cable construction, tray covers and
diversification of the cable loading.

“With these latest revisions, ANSI/NEMA WC 51/P-54-440 will be even
more helpful to the electrical utility industry,” said E.J. Bartolucci,
a member of the working group that revised the standard. “It is an
informative, easy-to-reference resource for the complex task of
establishing ampacity ratings of cables installed in cable trays.”

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