445.13(B) Overcurrent Protection Provided.
Code Change Summary: A new code section was added to address generators equipped with a listed overcurrent protective device.
Section 445.19 in the 2011 NEC® permitted a single generator supplying more than one load, or multiple generators operating in parallel to supply either of the following:
(1) A vertical switchboard with separate sections
(2) Individual enclosures with overcurrent protection tapped from a single feeder for load separation and distribution if a generator(s) is provided with overcurrent protection meeting the requirements of 240.15(A).
This language was deleted in the 2014 NEC® since it could be seen as conflicting with the separation requirements in 700.10(B). As well, Article 445 is all about the generator and is not so much about what the generator is permitted to supply.
Since the deletion of 445.19, there has been confusion about tap connections to generator terminals. In the 2017 NEC®, 445.13(B) was added to address tapping. The new rule states: Where the generator set is equipped with a listed overcurrent protective device or a combination of a current transformer and overcurrent relay, conductors shall be permitted to be tapped from the load side of the protected terminals in accordance with 240.21(B).
Basically, if the generator has a listed overcurrent device, taps can be made on the load side of the generator terminals as long as the tap rules in 240.21(B) are followed.
Below is a preview of the NEC®. See the actual NEC® text at NFPA.ORG for the complete code section. Once there, click on their link to free access to the 2017 NEC® edition of NFPA 70.
2014 Code Language:
445.13 Ampacity of Conductors. The ampacity of the conductors from the generator terminals to the first distribution device(s) containing overcurrent protection shall not be less than 115 percent of the nameplate current rating of the generator. It shall be permitted to size the neutral conductors in accordance with 220.61. Conductors that must carry ground-fault currents shall not be smaller than required by 250.30(A). Neutral conductors of dc generators that must carry ground-fault currents shall not be smaller than the minimum required size of the largest conductor.
Exception: See the NEC® for the exception.
2017 Code Language:
445.13 Ampacity of Conductors.
(A) General. The ampacity of the conductors from the generator output terminals to the first distribution device(s) containing overcurrent protection shall not be less than 115 percent of the nameplate current rating of the generator. It shall be permitted to size the neutral conductors in accordance with 220.61. Conductors that must carry ground-fault currents shall not be smaller than required by 250.30(A). Neutral conductors of dc generators that must carry ground-fault currents shall not be smaller than the minimum required size of the largest conductor.
Exception: See the NEC® for the exception which was unchanged.
N 445.13(B) Overcurrent Protection Provided. Where the generator set is equipped with a listed overcurrent protective device or a combination of a current transformer and overcurrent relay, conductors shall be permitted to be tapped from the load side of the protected terminals in accordance with 240.21(B).
Tapped conductors shall not be permitted for portable generators rated 15 kW or less where field wiring connection terminals are not accessible.