Q. What is the NEC rule for the ampacity of flexible cords and flexible cables?
See the answer below.
A. Table 400.5(A)(1) lists the allowable ampacity for copper conductors in flexible cords and Table 400.5(A)(2) lists the allowable ampacity for copper conductors in flexible cords with not more than three current-carrying conductors at an ambient temperature of 86ºF [Sec. 400.5].
Where the number of current-carrying conductors in a cable or raceway exceeds three, the allowable ampacity of each conductor must be adjusted in accordance with the following multipliers:
If the ambient temperature is other than 86°F, the flexible cord or flexible cable ampacity, as listed in Table 400.5(A)(1) or Sec. 400.5(A)(2), must be adjusted by using the ambient temperature correction factors listed in Table 310.15(B)(2)(a).
Temperature ratings for flexible cords aren’t contained in the NEC, but UL listing standards state that flexible cords are rated for 60°C unless marked otherwise.
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