NM cable in steam pipe

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I have a three story victorian house. The owner wants a sub panel on the third floor to feed additional loads including baseboard heat. All floors of the house are finished so fishing to the third floor will be dificult. There is an abandoned steam pipe that runs from the basement to the third floor. Assuming the NM cable doesnot fill more than 53% of the pipe, can the pipe be used to sleeve the NM cable through?
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
250.86 and its exceptions strongly imply that this sleeve needs to be bonded.


250.86 Other Conductor Enclosures and Raceways. Except
as permitted by 250.112(I), metal enclosures and raceways
for other than service conductors shall be grounded.

Well, it is not a raceway, and it does not appear to be an enclosure as defined in article 100, so I would suggest this paragraph would not apply to this situation.
 

ngd4130

Member
Well, it is not a raceway, and it does not appear to be an enclosure as defined in article 100, so I would suggest this paragraph would not apply to this situation.

IMO I believe it is a raceway - the four items which need compliance in exception #1 may apply especially (4) which if behind walls would not be in contact with persons.
 

iwire

Moderator
Staff member
Location
Massachusetts
IMO I believe it is a raceway

It is not a raceway, it was never designed expressly for holding wires.

Raceway. An enclosed channel of metal or nonmetallic materials
designed expressly for holding wires, cables, or busbars,
with additional functions as permitted in this Code.
Raceways include, but are not limited to, rigid metal conduit,
rigid nonmetallic conduit, intermediate metal conduit, liquidtight
flexible conduit, flexible metallic tubing, flexible
metal conduit, electrical nonmetallic tubing, electrical metallic
tubing, underfloor raceways, cellular concrete floor raceways,
cellular metal floor raceways, surface raceways, wireways,
and busways.
 

donselectric

Senior Member
Location
nh
if it wasn't designed for it then i would say its a listing/labeling violation technically speaking.
if you do use it bond it, its no different then sleeving a gec in emt your supposed to bond
both ends of emt . you cant pull a 10/3 up by it and put a sub pnl somewhere?
 

stickboy1375

Senior Member
Location
Litchfield, CT
if it wasn't designed for it then i would say its a listing/labeling violation technically speaking.
if you do use it bond it, its no different then sleeving a gec in emt your supposed to bond
both ends of emt . you cant pull a 10/3 up by it and put a sub pnl somewhere?

Bonding both ends of of a GEC in emt is not the same, sorry.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Well, it is not a raceway, and it does not appear to be an enclosure as defined in article 100, so I would suggest this paragraph would not apply to this situation.
It is a metal enclosure used to provide support or protection. Exception #2 says short sections of metal used for this purpose need not be bonded. It implies that long sections need to be bonded and this is, in my opinion, a long section. As far as the Article 100 definition of enclosure, it does say this is not an enclosure, but I think it is for the purposes of this exception. I don't how an enclosure meeting that definition would be used as described in the exception.
Also look at 250.4(B)(2). I don't see any way that section would not apply to this object.
 

stew

Senior Member
this object is just as likely to become energized as a metal water piping system. In my opinion due to the fact that ther are conductors within this protective tube it is even more likley to become energized than a wter pipe which has little or no contact with the conductors . In my opinion 250.4(A)(4),250.4(B)(2), and 250.4(B)(3) all apply . take your pick. I would definatley bond this pipe based on these sections and in compliance with 250.122 size wise.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
It is a metal enclosure used to provide support or protection. Exception #2 says short sections of metal used for this purpose need not be bonded. It implies that long sections need to be bonded and this is, in my opinion, a long section. As far as the Article 100 definition of enclosure, it does say this is not an enclosure, but I think it is for the purposes of this exception. I don't how an enclosure meeting that definition would be used as described in the exception.
Also look at 250.4(B)(2). I don't see any way that section would not apply to this object.

It is not an enclosure if it does not meet the NEC definition of enclosure.

Enclosure. The case or housing of apparatus, or the fence
or walls surrounding an installation to prevent personnel
from accidentally contacting energized parts or to protect
the equipment from physical damage.

Its not a fence or a wall, so that would mean it would need to be a case or housing of apparatus. It certainly does not appear to meet the common definitions of case or housing, and I don't see how wires can be considered apparatus. None of these terms are defined in the code, so that would mean their common meanings would come into play. I took a look at the MW online dictionary and did not find any meanings of these words that would seem to correlate with this situation.

OTOH, it would cost you very little to bond it, but it would have to be bonded with the same EGC as the conductors that pass thru it.

BTW, the code does not define long or short either.

I am not sure where the idea of not filling it up more then 53% came from. probably a good idea, but that would be for NM in a raceway and I think we have established this is not a raceway. As a practical matter though, it may be very hard to pull it if it is any fully than that.
 
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rbalex

Moderator
Staff member
Location
Mission Viejo, CA
Occupation
Professional Electrical Engineer
Section 250.4(A)(3) specifically requires bonding. "Likely to become energized" isn't even a consideration.
 
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iwire

Moderator
Staff member
Location
Massachusetts
Section 250.4(A)(3) specifically requires bonding. "Likely to become energized" isn't even a consideration.

That would mean when I snake a wire in a metal stud bay that I would have to bond the studs and I don't see that happening. (Other than Florida which has an amendment)
 

rbalex

Moderator
Staff member
Location
Mission Viejo, CA
Occupation
Professional Electrical Engineer
That would mean when I snake a wire in a metal stud bay that I would have to bond the studs and I don't see that happening. (Other than Florida which has an amendment)
It says what it says; I'm only applying Charlie's rule.
 

Little Bill

Moderator
Staff member
Location
Tennessee NEC:2017
Occupation
Semi-Retired Electrician
If the NM is going into/out of the pipe unspliced, how would you go about bonding to the pipe? Put a jb on both ends of the pipe?
 
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