310-15 B7

[Toros]

Hi
Can I use 310-15B7 for apartment feeder sizing,
when all apartment feeeders are protected by 60A, 2P cir. Brkrs ????????


or, this chart/Article is for residet. feeders w/ 100A and up OCPDs

Thank you

 

[texie]

Hi
Can I use 310-15B7 for apartment feeder sizing,
when all apartment feeeders are protected by 60A, 2P cir. Brkrs ????????


or, this chart/Article is for residet. feeders w/ 100A and up OCPDs

Thank you

No.

 

[Julius Right]

NEC 2014 art.310.15 (B)(7) 120/240 Volt, Single-Phase Dwelling Services and Feeders. For service and feeder conductors of 120/240- volt, single-phase, individual dwelling unit one-family, two-family, and multifamily service RATINGS FROM 100 amperes THROUGH 400 amperes, an adjustment factor of 0.83 of the service ampere rating shall be permitted to be used to determine the size of the ungrounded conductors.
Since 60<100 you cannot use this adjustment factor.:weeping: