My problem with the question is its use of the word ?allowable.? There is no code article that says what is allowable and what is not. There is simply Table 8, and from that you can directly read the size of the strand. And the strand is not a #14.
The diameter of each strand given in Table 8 is 1.89 mm. The area of a strand is given by Pi times the square of the diameter divided by 4, and is 2.81 mm2. That puts each strand between a #14 (area 1.08 mm2) and a #12 (area 3.31 mm2). The area of 19 of these strands would then be 53.3 mm2. The tabulated area of a 1/0 is 53.49 mm2, making the gap space between the individual strands fairly small at 1.9 mm2 or so.
