Bundling conductors

Status
Not open for further replies.
D

Djelite

Senior Member
Location
Ny
Occupation
Electrician
The nec allos you to bundle conductors as long as it doesn’t exceed 10ft or 10 % of the entire run(310.15a2ex). Does this also apply to conductors terminating in panels?code reference please.
 
Yes bundling is bundling so the same rule you mentioned would apply to using cable ties in a panel.
 
infinity said:
Yes bundling is bundling so the same rule you mentioned would apply to using cable ties in a panel.
Click to expand...
(2020) Table 310.16 is labeled "Ampacities of Insulated Conductors with Not More Than Three Current-Carrying Conductors in Raceway, Cable, or
Earth (Directly Buried)." So I don't think that derating for CCCs or bundling applies within a panel.

310.15(C)(1) does say "The ampacity of each conductor shall be reduced as shown in Table 310.15(C)(1) where the number of current-carrying conductors in a raceway or cable exceeds three, or where single conductors or multiconductor cables not installed in raceways are installed without maintaining spacing for a continuous length longer than 600 mm (24 in.)."

So I guess you could argue that if your panel has more than 24" of bundled single conductors within it, derating could apply, under the "single conductors . . . not installed in raceways" language. Is that really the intent, or it is just meant to apply to unenclosed single conductors?

Cheers, Wayne
 
wwhitney said:
310.15(C)(1) does say "The ampacity of each conductor shall be reduced as shown in Table 310.15(C)(1) where the number of current-carrying conductors in a raceway or cable exceeds three, or where single conductors or multiconductor cables not installed in raceways are installed without maintaining spacing for a continuous length longer than 600 mm (24 in.)."
Click to expand...
The bold part applies to conductors bundled within the panel.
 
infinity said:
The bold part applies to conductors bundled within the panel.
Click to expand...
Hence my question as to whether that was really the intention, or if it should read "not installed in raceways or enclosures."

An apparent bundling loophole given the 24" exemption on bundling is to simply use a series of <24" nipples, possibly free floating, to split your bundled length into alternating sections of bundle in a raceway, and not in a raceway, each section being under 24".

Cheers, Wayne
 
Yes but my question was about the exception. 310.15a2ex) as it applied to conductors in a panel. Not necessarily this rule
 
wwhitney said:
Hence my question as to whether that was really the intention, or if it should read "not installed in raceways or enclosures."
...
Cheers, Wayne
Click to expand...
That is the intention as in the 2014 code the section title was changed from "More Than Three Current-Carrying Conductors in a Raceway or Cable" to "More Than Three Current-Carrying Conductors" because the section covers all locations where conductors are installed without maintaining spacing.
 
How do you determine bundling in a panel. Heck most panels are more than 24" so are we suggesting that bundling must occur there. There is so much air inside a panel as opposed to a raceway that it seems unwise to include a panel.

Is the only time it is considered bundling in a panel is if there are tie wraps around the conductors? There is definitely space between the conductors, IMO so I don't see it applying
 
Dennis Alwon said:
How do you determine bundling in a panel. Heck most panels are more than 24" so are we suggesting that bundling must occur there. There is so much air inside a panel as opposed to a raceway that it seems unwise to include a panel.

Is the only time it is considered bundling in a panel is if there are tie wraps around the conductors? There is definitely space between the conductors, IMO so I don't see it applying
Click to expand...
IMO panels and switchboards should be exempt but they aren't. I would consider this bundling:IMG_20160229_142536.jpg
 
don_resqcapt19 said:
That is the intention as in the 2014 code the section title was changed from "More Than Three Current-Carrying Conductors in a Raceway or Cable" to "More Than Three Current-Carrying Conductors" because the section covers all locations where conductors are installed without maintaining spacing.
Click to expand...
Was that your proposal?

I looked up the ROP and the ROC, and I see the deletion was about avoiding the conflict between the section heading and the section text. There was no specific commentary on whether the language about "single conductors or multiconductor cables . . . installed without maintaining spacing" was meant to apply only outside of raceways and enclosures (e.g. bundling multiple cables) or was in fact meant to apply inside enclosures (e.g. cable tying conductors). Do you have any reference to CMP activity that bears on that question?

On the other hand, if bundling is an issue in free air, I guess there's no reason that it wouldn't be an issue inside a panel, so it makes sense it should apply there.

Cheers, Wayne
 
infinity said:
I would consider this bundling:
Click to expand...
Now agreed.

Makes me wonder why there isn't a readily available plastic "collator disk" that has 6 or 7 little openings on the edge that let you snap the individual conductors into. (Or maybe a square that has two openings on opposite sides, and the other two sides allow the squares to be gangable.) That would let you organize things neatly while "maintaining spacing."

Cheers, Wayne
 
Status
Not open for further replies.
Top