jar546
CBO
Can anyone show us how to properly size conductors that are serving a continuous load, with more than 3 current carrying conductors in a raceway and run in an attic or roof where ambient temperature adjustment factors apply?
I call this the trifecta of conductor sizing adjustments. The 2014 NEC addresses this issue with a clarification, not a change. Here is an example I would like to see the answer from more several people:
You have a 2 branch circuits that feed continuous loads of 19A and 28A through a single 1-1/4" EMT conduit that runs through an attic with a temperature of 140F. There are 4 current carrying conductors in the single conduit, 2 for each 240v continuous load. What wire sizes and OCPD would have to be installed to be code compliant if THHN/THWN were used?
I call this the trifecta of conductor sizing adjustments. The 2014 NEC addresses this issue with a clarification, not a change. Here is an example I would like to see the answer from more several people:
You have a 2 branch circuits that feed continuous loads of 19A and 28A through a single 1-1/4" EMT conduit that runs through an attic with a temperature of 140F. There are 4 current carrying conductors in the single conduit, 2 for each 240v continuous load. What wire sizes and OCPD would have to be installed to be code compliant if THHN/THWN were used?