392.80(A)(2)(D) Doubt, this is correct?

[Emiliano]

Hello everyone, Acoording to NEC articulo 392.80(A)(2)(D), "where single conductors are installed in a triangular or square configuration in uncovered cable trays, with a maintained free airspace not less tha 2.15 times one conductor diameter of the largest conductor contained of the adjacent conductor configurations or cables, the ampacity of 1/0 AWG and larger cables shall not exceed the allowable ampacities of two or three single conductors rated 0 through 2000 volts supported on a messenger in accordance with 310-.15 (B), see table 310.15(B)(20)"

so my doubt is: in this kind of arragment we take the ampacity of two or three conductors only?
for example: the total ampacity of the circuit is 2900A or 1740A? taking 310.15(B)(20) table.

 

[don_resqcapt19]

The ampacity is 2900 however that is at 90°C. You would have to make sure your equipment is rated the 90°C ampacity. In addition the rules in 110.14 will limit the terminations to the ampacities found in Table 310.15(B)(16) unless the equipment is marked otherwise.