If the overcurrent protection rules in Article 240 apply to the neutral, how can we size the neutral based on the neutral current as permitted for feeders? The only requirement for the feeder neutral size is the larger of what is required for the load or the size of the required EGC for the circuit. This often results in a neutral that is really only protected by the design calculations, not by the ungrounded conductor OCPD.
Yes, I know that I said that the rules in 240 apply to the neutral in an earlier post, but there are issues with that when we are talking about feeder circuits.
Okay, so now I guess this indirectly seems to bring back the issue I was struggling with earlier. If we know that neutral current carrying capacity is not based directly on the rating of overcurrent protection for feeders and services, would this not also apply to all branch circuit neutral conductors as well?
Especially with regard to the situation covered in 240.4[D] for #14 conductors being used as a neutral for 20A branch circuits.
