wwhitney
Senior Member
- Location
- Berkeley, CA
- Occupation
- Retired
New version (markup version messed up by TerraView):
210.19(A) General.
Branch-circuit conductors shall be sized not smaller than either of the following:
(1) The minimum branch-circuit conductor size shall have an ampacity in accordance with 110.14(C)(1) not less than the noncontinuous load plus 125 percent of the continuous load.
Exception (1): If the assembly, including the branch-circuit OCPDs, is listed for continuous operation at 100 percent of its rating, the minimum branch-circuit conductor size shall be permitted to have an ampacity in accordance with 110.14(C)(1) not less than the load.
Exception (2): Where a portion of a branch circuit is connected at both its supply and load ends to separately installed pressure connections, the size of that portion of the branch-circuit conductors shall be permitted to have an ampacity in accordance with 110.14(C)(2) not less than the load. No portion of a branch circuit installed under this exception shall extend into an enclosure containing either the branch-circuit supply or the branch-circuit load terminations.
(2) The minimum branch-circuit conductor size shall have an ampacity not less than the maximum load to be served after the application of any adjustment or correction factors in accordance with 310.15.
Substantiation:
This rearrangement of 210.19(A) improves clarity in a number of ways without changing the intended meaning:
- Consistently refer to the conductor size as the subject of the requirements.
- Reinforce the distinction between the two different methods for determining ampacity in subsections (1) and (2) by associating the references to section 110.14(C) or 310.15 more closely to the term "ampacity".
- Replace the lengthy phrase "sum of the continuous and noncontinuous loads" with the equivalent and shorter term "load".
- Move the second exception to subsection (1), as really the difference in the situation described is the applicability of 110.14(C)(2) rather than 110.14(C)(1). Subsection (2) still applies to such portions of the branch circuit wiring, and so should be not be excepted.
210.19(A) General.
Branch-circuit conductors shall be sized not smaller than either of the following:
(1) The minimum branch-circuit conductor size shall have an ampacity in accordance with 110.14(C)(1) not less than the noncontinuous load plus 125 percent of the continuous load.
Exception (1): If the assembly, including the branch-circuit OCPDs, is listed for continuous operation at 100 percent of its rating, the minimum branch-circuit conductor size shall be permitted to have an ampacity in accordance with 110.14(C)(1) not less than the load.
Exception (2): Where a portion of a branch circuit is connected at both its supply and load ends to separately installed pressure connections, the size of that portion of the branch-circuit conductors shall be permitted to have an ampacity in accordance with 110.14(C)(2) not less than the load. No portion of a branch circuit installed under this exception shall extend into an enclosure containing either the branch-circuit supply or the branch-circuit load terminations.
(2) The minimum branch-circuit conductor size shall have an ampacity not less than the maximum load to be served after the application of any adjustment or correction factors in accordance with 310.15.
Substantiation:
This rearrangement of 210.19(A) improves clarity in a number of ways without changing the intended meaning:
- Consistently refer to the conductor size as the subject of the requirements.
- Reinforce the distinction between the two different methods for determining ampacity in subsections (1) and (2) by associating the references to section 110.14(C) or 310.15 more closely to the term "ampacity".
- Replace the lengthy phrase "sum of the continuous and noncontinuous loads" with the equivalent and shorter term "load".
- Move the second exception to subsection (1), as really the difference in the situation described is the applicability of 110.14(C)(2) rather than 110.14(C)(1). Subsection (2) still applies to such portions of the branch circuit wiring, and so should be not be excepted.