Proposal 2-134 and branch circuit neutral size 210.19

[tortuga]

Recommendation: Add new text to read as follows:
210.19(A)(5) Grounded Conductor. The size of the branch circuit grounded
conductor shall not be smaller than that required by 250.122, except that
250.122(F) shall not apply where grounded conductors are run in parallel.
Substantiation: As the code is now, it is possible, although a rare occurrence,
where one could reduce a branch circuits grounded conductor?s size smaller
than the ungrounded conductors and the equipment grounding conductor, but
under 210.19(A)(4) it is possible. In 215.2(A)(2) for feeders we have guidance
that the grounded conductor must not be smaller than the EGC that is required
in Table 250.122. We are not given that same assurance for a branch circuit. I
believe it is never the intent of the NEC to allow a grounded conductor to be
smaller than the required equipment grounding conductor.
Panel Meeting Action: Reject
Panel Statement: It is unclear to the panel how the submitter is interpreting
that 210.19(A)(4) could result in a grounded conductor smaller than the
ungrounded conductors and the equipment grounding conductor.
Number Eligible to Vote: 11
Ballot Results: Affirmative: 11
________________________________________________________________

Here was a interesting proposal dealing with L-N faults, any set of wires in a circuit should be capable of tripping the OCPD. If for some reason the ECG is increased in size beyond the size in 250.122 the neutral (read grounded conductor) can be smaller than the ECG but not smaller than 250.122. Seems fine with since conduit could be the EGG or the ECG could be upsized for sharing with a larger circuit. OK Looks like a good proposal.

Now I am not getting the reasoniong why the panel rejected it?
210.19(A)(4) permits conductors to be sized at an ampacity sufficient for the loads served.
Seems like neutrals need to be sized for the neutral load.
Where in the NEC are multi wire branch circuit conductors required to all be the same size for say a hot tub?
Did the panel not consider a standard 11kw hot tub with #6cu THHN, ECG of 8 THHN (oversized) and a 14 AWG neutral. It has a 750W neutral load for a light and blower, what is preventing someone from pulling a 14awg neutral?
Thanks

The proposal could have removed the 210.19 (3) exception #2 that requires a 10AWG neutral on a 2.5 kw 3 wire 20A counter top cooker circuit as well.

 

[jumper]

The proposal could have removed the 210.19 (3) exception #2 that requires a 10AWG neutral on a 2.5 kw 3 wire 20A counter top cooker circuit as well.

I believe that section is for equipment of 8 3/4kW and above.

Exception No. 2: The neutral conductor of a 3-wire
branch circuit supplying a household electric range, a
wall-mounted oven, or a counter-mounted cooking unit
shall be permitted to be smaller than the ungrounded conductors
where the maximum demand of a range of 8 3⁄4-kW
or more rating has been calculated according to Column C
of Table 220.55, but such conductor shall have an ampacity
of not less than 70 percent of the branch-circuit rating and
shall not be smaller than 10 AWG.


PS. IIRC, that is Dennis Alwon's proposal.

 

[tortuga]

Oh Yeah correct i just read it too quickly.

I think the manufacturers could just use 240 clocks and control panels (like EU models) since they dont use a neutral for anything else.
Then ranges could go back to 3 wire and use a 6-50.

 

[Dennis Alwon]

I have had to shake my head a few times at the cmp's decisions and responses. I will say I got a few accept and a few accepted in principle. Not bad, IMO for a first timer. I had written another one where their response was totally off- I posted it here a few months back.

 

[jumper]

I have had to shake my head a few times at the cmp's decisions and responses.

One problem I see with the CMPs is that sometimes they do not seem to recognize that certain sections can be interpreted in more than one way.

 

[Dennis Alwon]

One problem I see with the CMPs is that sometimes they do not seem to recognize that certain sections can be interpreted in more than one way.

It actually is not a real important issue so.. Most of mine are pretty mild esp. when compared to that crazy guy George Stolz

Here is the thread I mentioned above http://forums.mikeholt.com/showthread.php?t=146211&highlight=proposal

 

[fmtjfw]

It actually is not a real important issue so.. Most of mine are pretty mild esp. when compared to that crazy guy George Stolz

Here is the thread I mentioned above http://forums.mikeholt.com/showthread.php?t=146211&highlight=proposal

And have you seen the weird stuff that whack job Williams proposed?

 

[Dennis Alwon]

And have you seen the weird stuff that whack job Williams proposed?

A lot more than I proposed I know. You are busy at it. I really never thought that I would ever write a proposal but I also never thought I would be a mod either. Funny how things go.