I agree with Smart$. According to NEC 392.22(A)(1)
"Where ladder or ventilated trough cable trays"
(b) Where all of the cables are smaller than 4/0 AWG ?shall not
exceed the maximum allowable cable fill area in Column 1
of Table 392.22(A) for the appropriate cable tray width.
However further:
(3) Where solid bottom cable trays contain multiconductor
power or lighting cables,
(b) Where all of the cables are smaller than 4/0 AWG maximum allowable cable fill area in Column 3
of Table 392.22(A) for the appropriate cable tray width.
Since Davebones did not indicate the cable tray type [could be solid bottom?]
In this case the permitted filling will be only 11 inch^2 [for 12" width] and maximum number of cables will be only 50.
Now-as Smart$ said-the ampacity will be a problem.
NEC states:
392.17 Ampacity of Conductors
(A) Ampacity of Cables, Rated 2000 Volts or Less, in
Cable Trays.
"(1) The allowable ampacity of multiconductor cables,
nominally rated 2000 volts or less, installed according to
the requirements of 392.22(A) shall be as given in Table
310.15(B)(16) and Table 310.15(B)(18), subject to the provisions
of (1), (2), (3), and 310.15(A)(2)."
For 12 awg 90dgr.C Table 310.15(B)(16) sais :30 A [30dgr.C ambient].
For the same depth [aprox.1"] ICEA P-54-440 Table 3-3 [recalculated for 0.53"dia and 30dgr.C ] states only 17.6 A.
