250.122(B) 2014

[augie47]

I may never see 2014 adopted in this area but sometimes it's difficult to explain 250.122(B) to folks when they increase phase conductors foe any reason, the EGC must be proportionally addressed.
2014 has changed the wording of 250.122(B) and I don't fully understand the change.
Does it take us back to the days where EGC increases were only need for conductor increases for voltage drop ?

 

[charlie b]

I started a thread on this same topic. It may either add to or resolve your confusion. But here it is:
http://forums.mikeholt.com/showthread.php?t=164866

 

[Smart $]

It was never intended to include upsizing to compensate for adjustment and correction.

Here's the proposal for when it changed [2002] to include other than upsizing for voltage drop...

5- 264 - (250-122): Accept
SUBMITTER: Jamie McNamara, Hastings, MN
RECOMMENDATION: Revise to read as follows:
250-122 (b) Increased in size Adjustment for Voltage Drop. Where
ungrounded conductors are increased adjusted in size to
compensate for voltage drop, equipment grounding conductors,
where installed, shall be increased in size adjusted proportionately
according to circular mil area of the ungrounded conductors.
SUBSTANTIATION: The current text is limited to voltage drop
only and is subject to abuse and misinterpretation (e.g. it was
done per the plans, not for voltage drop). The manufacturers
directions often call for conductor to be increased in size, with
no explanation for why the ungrounded conductors size is
increased, with no corresponding requirement for the equipment
grounding conductor to be increased.
PANEL ACTION: Accept.
NUMBER OF PANEL MEMBERS ELIGIBLE TO VOTE: 17
VOTE ON PANEL ACTION:
AFFIRMATIVE: 16
NEGATIVE: 1
EXPLANATION OF NEGATIVE:
TOOMER: The submitter did not provide sufficient
substantiation.

 

[don_resqcapt19]

It was never intended to include upsizing to compensate for adjustment and correction. ...

But the physics doesn't care why the size was increased. If the physics says (not really sure that it does, but the code is telling us that it does) that you need to increase the size of the EGG if you use a #8 on a 20 amp breaker, than that would really apply no matter why the conductor was sized larger than #12.

 

[Smart $]

But the physics doesn't care why the size was increased. If the physics says (not really sure that it does, but the code is telling us that it does) that you need to increase the size of the EGG if you use a #8 on a 20 amp breaker, than that would really apply no matter why the conductor was sized larger than #12.

I agree, under 2002 thru 2011 edition purview, it can be interpreted that way. Just saying to include adjustment and correction as an upsized situation was never intended.

Under the revised text of 2014, where the minimum size circuit conductor is #10 or #8 to compensate for adjustment and correction, you will not have to upsize the EGC to match.

 

[augie47]

I started a thread on this same topic. It may either add to or resolve your confusion. But here it is:
http://forums.mikeholt.com/showthread.php?t=164866

Thanks Charlieb.
I vaguely recalled it but could not locate it on my search.
I moved my comment to there and will close this.