**[FONT=Arial]Here’s a piece from the handbook.
IMO I would call the use of romex a defect in the area you described.
[/FONT]**The current, in amperes, that a conductor can carry continuously under the conditions of use without exceeding its temperature rating.
The definition of the term *ampacity *states that the maximum current a conductor carries
continuously varies with the conditions of use as well as with the temperature rating of the conductor insulation.
For example, ambient temperature is a condition of use.
A conductor with insulation rated at 60°C and installed near a furnace where the ambient temperature is continuously maintained at 60°C has no current-carrying capacity.
Any current flowing through the conductor will raise its temperature above the 60°C insulation rating.
Therefore, the ampacity of this conductor, regardless of its size, is zero.
See the ampacity correction factors for temperature at the bottom of Table 310.16 through Table 310.20, or see Annex B.
The temperature limitations on conductors is further explained and examples given in 310.10 and in the commentary following that section.
310.10 Temperature Limitation of Conductors
[FONT=Arial]No conductor shall be used in such a manner that its operating temperature exceeds that designated for the type of insulated conductor involved. In no case shall conductors be associated together in such a way, with respect to type of circuit, the wiring method employed, or the number of conductors, that the limiting temperature of any conductor is exceeded.