Article 215.2(A) - 2014 Ammendments

[_Ix]

Hey all,

I had some questions regarding the changes to Article 215.2(A):

215.2 Minimum Rating and Size.

(A) Feeders Not More Than 600 Volts.

(1) General. Feeder conductors shall have an ampacity not
less than required to supply the load as calculated in Parts
III, IV, and V of Article 220. Conductors shall be sized to
carry not less than the larger of 215.2(A)(1)(a) or (b).

(a) Where a feeder supplies continuous loads or any
combination of continuous and noncontinuous loads, the
minimum feeder conductor size shall have an allowable
ampacity not less than the noncontinuous load plus
125 percent of the continuous load.

(b) The minimum feeder conductor size shall have an
allowable ampacity not less than the maximum load to be
served after the application of any adjustment or correction
factors.

I'm getting some City Officials commenting that my feeders are undersized to some panels. Is this code section telling me that I would need to size my feeder for the connected load plus 125% of any continuous loads, rather than sizing my feeder for the diversified load of the panel (50% of receptacles after the first 10KVA, etc)?

What is the intent for these changes in the 2014 code? The more I read it, the more it makes me feel like any diversity or demand factors are rendered useless. Surely, this is not the intent.

 

[david luchini]

What is the intent for these changes in the 2014 code? The more I read it, the more it makes me feel like any diversity or demand factors are rendered useless. Surely, this is not the intent.

The load as calculated in Parts III, IV and V of Art 220 include the demand factors. IMO, the Code intent in 215.2 (A) hasn't changed, just the way it is worded.

 

[infinity]

You can read the reasoning from the 2014 ROP:

2-201 Log #2252 NEC-P02 Final Action: Accept in Principle
(215.2(A)(1))
________________________________________________________________
Submitter: Charles R. Miller, Charles R. Miller Electrical Education and
Training
Recommendation: Add text to read as follows:
(1) General. Feeder conductors shall have an ampacity not less than required
to supply the load as calculated in Parts III, IV, and V of Article 220. Circuit
conductors shall be sized to carry not less than the larger of215.2CA)(] )Ca) or
(l)(b).
(a) The minimum feeder-circuit conductor size shall have an allowable
ampacity not less than the noncontinuous load plus 125 percent of the
continuous load.
(b) The minimum feeder-circuit conductor size shall have an allowable
ampacity not less than the load after conditions of use have been applied.
Substantiation: The text ?before the application of any adjustment or
correction factors? is misleading. As written, the last sentence in 215.2(A)(l) is
specifying to multiply continuous loads by 125 percent and then apply the
additional correction factors for conditions of use. Then new wording will
make it clear that there are two separate calculations. After comparing 215.2(A)
(l)(a) and (l)(b), the larger size conductor is then selected.
Panel Meeting Action: Accept in Principle
Revise 215.2(A)(1) to read as follows:
?(1) General. Feeder conductors shall have an ampacity not less than required
to supply the load as calculated in Parts III, IV, and V of Article 220.
Conductors shall be sized to carry not less than the larger of (a) or (b).
(a) Where a feeder supplies continuous loads or any combination of
continuous and noncontinuous loads, the minimum feeder conductor size shall
have an allowable ampacity not less than the noncontinuous load plus 125
percent of the continuous load.
(b) The minimum feeder conductor size shall have an allowable ampacity not
less than the maximum load to be served after the application of any
adjustment or correction factors.?
The panel notes that the Exception and Informational Notes are unchanged
by the action taken on this proposal.
Panel Statement: The revised wording meets the intent of the submitter.
The panel agrees with the submitter?s intent and has restructured the section
to create the two conditions for determining the minimum feeder size.
In addition, the panel reworded the recommended (b) to utilize the
terminology of ?adjustment or correction factors? as it is clearer than
?conditions of use?.
Number Eligible to Vote: 11
Ballot Results: Affirmative: 11