Neutral load conductor sizing

[donf]

In the 2008 edition of code, citation 210.19(A)(1) Exception #2 was introduced.

This exception allowed you to size the Neutral conductor at 100% of the continuous load plus 100% of the non continuous load.

The 2011 edition as well as the pending 2014 edition do not have this exception.

Question, was this exception incorporated somewhere else or do we now size the Neutral load at 125% of the continuous load plus 100% of the non continuous load?

 

[don_resqcapt19]

Here is the proposal that removed that exception.

2-198 Log #4583 NEC-P02 Final Action: Accept
(210.19(A)(1) Exception No. 2)
_______________________________________________________________
Submitter: Frederic P. Hartwell, Hartwell Electrical Services, Inc.
Recommendation: Delete this exception.
Substantiation: This exception should be reserved for instances where the grounded conductor runs from busbar to busbar, as is the case for a feeder. Branch circuit applications typically involve runs from busbar to device, and
the equipment on the other end of the wire may not be as forgiving as the connection on a busbar. IT should also be pointed out that the exception is not limited to neutrals, and there are applications where the grounded conductor
will be a phase conductor. The literal text could then result in two different sizes of wire arriving at the same device and carrying the same current, and therefore causing unequal heating across the device terminals. The version of
this provision that applies in Article 215 is perfectly acceptable, but the wording here was never fully substantiated. In addition, there appears to be little real-world need for this allowance, and it should be either withdrawn or
severely limited if it stays in the NEC at all.
Panel Meeting Action: Accept
Number Eligible to Vote: 12
Ballot Results: Affirmative: 12

There were no comments on this change in the Report on Comments

 

[tom baker]

Interesting - this was Mike Holts proposal. It made perfect sense.