wwhitney
Senior Member
- Location
- Berkeley, CA
- Occupation
- Retired
My 2nd PI by location in the NEC.
Cheers, Wayne
110.14(C)(1) Equipment Provisions.
The determination of termination provisions of equipment shall be based on 110.14(C)(1)(a) or (C)(1)(b). Unless the equipment is listed and marked otherwise, conductor ampacities used in determining equipment termination provisions shall be based on Table 310.16 as appropriately modified by 310.12.
(a) Termination provisions of equipment for circuits rated 100 amperes or less, or marked for 14 AWG through 1 AWG conductors, shall be used only for one of the following:
Statement of Problem and Substantiation for Public Input
This proposal consists of two changes for greater clarity and logical correctness. 110.14(C) has historically been a source of confusion for many in the electrical trades.
The first change is to 110.14(C)(1)(a)(2) to simply match the language used in 110.14(C)(1)(b)(2).
The second change is to follow the second use of the word "ampacity" in both sections with the parenthetical comment "before adjustment and correction factors." It is commonly understood that the termination temperature limitations in 110.14(C) refer to the table values from Table 310.16, without applying any adjustment and correction factors. This is shown in Example D3(a) in Annex D, in the section "Ungrounded Feeder Conductors."
However, the definition of "ampacity" refers to the "conditions of use", and 310.15 specifies that the ampacity "shall be as . . . modified by 310.15(A) through (F) . . ." So the term "ampacity" alone always properly means that adjustment and correction factors are to be applied (310.15(B) and (C)).
Thus, whenever it is desired to refer to the unadjusted and uncorrected values from Table 310.16, it is necessary to provider an appropriate modifier to the term ampacity. Therefore I suggest the modifier "before adjustment and correction factors."
Cheers, Wayne
110.14(C)(1) Equipment Provisions.
The determination of termination provisions of equipment shall be based on 110.14(C)(1)(a) or (C)(1)(b). Unless the equipment is listed and marked otherwise, conductor ampacities used in determining equipment termination provisions shall be based on Table 310.16 as appropriately modified by 310.12.
(a) Termination provisions of equipment for circuits rated 100 amperes or less, or marked for 14 AWG through 1 AWG conductors, shall be used only for one of the following:
(1) Conductors rated 60°C (140°F).
(2) Conductors with higher temperature ratings, provided the ampacity of such conductors is determined based on does not exceed the 60°C (140°F) ampacity (before adjustment and correction factors) of the conductor size used.
(3) Conductors with higher temperature ratings if the equipment is listed and identified for use with such conductors.
(4) For motors marked with design letters B, C, or D, conductors having an insulation rating of 75°C (167°F) or higher shall be permitted to be used, provided the ampacity of such conductors does not exceed the 75°C (167°F) ampacity.
(b) Termination provisions of equipment for circuits rated over 100 amperes, or marked for conductors larger than 1 AWG, shall be used only for one of the following:(1) Conductors rated 75°C (167°F)
(2) Conductors with higher temperature ratings, provided the ampacity of such conductors does not exceed the 75°C (167°F) ampacity (before adjustment and correction factors) of the conductor size used, or up to their ampacity if the equipment is listed and identified for use with such conductors
Statement of Problem and Substantiation for Public Input
This proposal consists of two changes for greater clarity and logical correctness. 110.14(C) has historically been a source of confusion for many in the electrical trades.
The first change is to 110.14(C)(1)(a)(2) to simply match the language used in 110.14(C)(1)(b)(2).
The second change is to follow the second use of the word "ampacity" in both sections with the parenthetical comment "before adjustment and correction factors." It is commonly understood that the termination temperature limitations in 110.14(C) refer to the table values from Table 310.16, without applying any adjustment and correction factors. This is shown in Example D3(a) in Annex D, in the section "Ungrounded Feeder Conductors."
However, the definition of "ampacity" refers to the "conditions of use", and 310.15 specifies that the ampacity "shall be as . . . modified by 310.15(A) through (F) . . ." So the term "ampacity" alone always properly means that adjustment and correction factors are to be applied (310.15(B) and (C)).
Thus, whenever it is desired to refer to the unadjusted and uncorrected values from Table 310.16, it is necessary to provider an appropriate modifier to the term ampacity. Therefore I suggest the modifier "before adjustment and correction factors."