Georges Proposals

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tom baker

tom baker

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Our moderator George has many proposals most he didn't win on. One interesting one is in 310, its very long, and the CMP said, well, we will take a look at it....
 
tom baker said:
Our moderator George has many proposals most he didn't win on. One interesting one is in 310, its very long, and the CMP said, well, we will take a look at it....
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are you going to post or link the proposal so we can take a look?
 
If you go here and go to "ROP Ballot" you can read or download all of the proposals and the "unofficial" action taken at the panel meetings. There is a file for each of the code making panels.
 
All ungrounded conductors capable of being energized simultaneously shall be
considered current-carrying.
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This makes sense except that many times there are a whole bunch of control conductors that have very little current flowing through them and thus generate no heat. There is no need to derate them.

Maybe it could be rewritten so that it refers to the branch circuits involved. I.e. - you only have to derate for each OCPD.
 
petersonra said:
All ungrounded conductors capable of being energized simultaneously shall be
considered current-carrying.
Click to expand...
This makes sense except that many times there are a whole bunch of control conductors that have very little current flowing through them and thus generate no heat. There is no need to derate them.

Maybe it could be rewritten so that it refers to the branch circuits involved. I.e. - you only have to derate for each OCPD.
Click to expand...

even multi-wire circuit could have all conductors energized at the same time, of course what is his definition of energized, is it meaning that current is flowing?
 
hurk27 said:
even multi-wire circuit could have all conductors energized at the same time, of course what is his definition of energized, is it meaning that current is flowing?
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With a MWC you would have more than one OCPD. My suggestion would be just to count the number of OCPD and consider that how many CCC. If you have a 3 phase MWC, you would have 3 CCC, even though there could potentially be hundreds of conductors involved.
 
petersonra said:
This makes sense except that many times there are a whole bunch of control conductors that have very little current flowing through them and thus generate no heat. There is no need to derate them.
That is already covered in the code rule.
310.15(B)(3)(a) ... Where conductors of different systems, as provided in 300.3, are installed in a common raceway or cable, the adjustment factors shown in Table 310.15(B)(3)(a) shall apply only to the number of power and lighting conductors (Articles 210, 215, 220, and 230).
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Control conductors would not be counted as current carrying conductors for the purpose of derating.
Maybe it could be rewritten so that it refers to the branch circuits involved. I.e. - you only have to derate for each OCPD.
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That would be a good code change as the use of multiple conductors on a single OCPD will always produce less heat in the cable or raceway than if a single conductor carried the full load.
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hurk27 said:
Here is the ROP for panel #6

and he was right it is long, scroll down to the PDF page 13 to 17

George are ya trying to keep them from ever getting it done on time or what :lol:
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You think that's bad - when the chair emailed me asking for a raw document version to play with, I also sent along a suggestion to spread what I had from 310.14 to 310.60 instead of what I suggested; complete with a conversion table. :D
 
don_resqcapt19 said:
petersonra said:
This makes sense except that many times there are a whole bunch of control conductors that have very little current flowing through them and thus generate no heat. There is no need to derate them.
Control conductors would not be counted as current carrying conductors for the purpose of derating.

That would be a good code change as the use of multiple conductors on a single OCPD will always produce less heat in the cable or raceway than if a single conductor carried the full load.
Click to expand...

There is a similar rule for wireways that control conductors do not have to be derated if under 10% of ampacity
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