#12 THHN cable assembly without a jacket.

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hconant

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Can THHN cable be run without a sheath or conduit? We need to install a new residential sub-panel from a crawl space to a new full basement. The branch circuits currently going to the old sub-panel need to be junctioned and relocated to the new sub-panel. We would like to get a cable assembly made of 15 #12 THHN wires, and two #6THHN (for the neutral and ground), then attach the assembly to the overhead joists in the crawl space where they will run to and into the new panel in the basement. I think this meets the requirement of being physically protected since the crawl space is not accessable for storage. We have also, on occasion run a single #14 THHN for smoke detector interface wire. Do these applications meet code?
 

don_resqcapt19

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Staff member
Location
Illinois
Occupation
retired electrician
No. See 310.13.
These conductors shall be permitted for use in any of the wiring methods recognized in Chapter 3 and as specified in their respective tables or as permitted elsewhere in this Code.
Don
 

infinity

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Location
New Jersey
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Journeyman Electrician
I think this meets the requirement of being physically protected since the crawl space is not accessable for storage. We have also, on occasion run a single #14 THHN for smoke detector interface wire. Do these applications meet code?

Not to be snide, but you're kidding , right?
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
Re: #12 THHN cable assembly without a jacket.

hconant said:
We would like to get a cable assembly made of 15 #12 THHN wires, and two #6THHN (for the neutral and ground)

Why would the ground ever need to be larger than the largest hot conductor? I would buy the neutral being larger.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
infinity said:
I think this meets the requirement of being physically protected since the crawl space is not accessable for storage. We have also, on occasion run a single #14 THHN for smoke detector interface wire. Do these applications meet code?

Not to be snide, but you're kidding , right?

I don't think he is.

Would a wire bundle assembly inside the blue corrugated tubing suffice?
 

iwire

Moderator
Staff member
Location
Massachusetts
Beside the other issues brought up sticking fifteen 12 AWG 'hots' with one 6 AWG neutrals in a common cable or raceway would run into serious derating issues.

Sounds like a 50% adjustment leaving you with at best 15 amp capacity 12 AWG and 38 amp rated 6 AWG.

Also some inspectors may question a single neutral for all. :wink:
 

iwire

Moderator
Staff member
Location
Massachusetts
Re: #12 THHN cable assembly without a jacket.

hconant said:
We have also, on occasion run a single #14 THHN for smoke detector interface wire. Do these applications meet code?

As strange as that is I believe it is acceptable depending on the smoke detector instructions.
 

infinity

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Staff member
Location
New Jersey
Occupation
Journeyman Electrician
When can you run 15 hot legs and one neutral through a crawl space without conduit?
 

celtic

Senior Member
Location
NJ
Re: #12 THHN cable assembly without a jacket.

hconant said:
Can THHN cable be run without a sheath or conduit?

I think this meets the requirement of being physically protected since the crawl space is not accessable for storage.

I don't think so...


300.3(B)
Conductors of the Same Circuit.
All conductors of the same circuit and, where used, the grounded conductor and all equipment grounding conductors and bonding conductors shall be contained within the same raceway, auxiliary gutter, cable tray, cablebus assembly, trench, cable, or cord, unless otherwise permitted in accordance with 300.3(B)(1) through (4).

hconant said:
We would like to get a cable assembly ..then attach the assembly to the overhead joists ... I think this meets the requirement of being physically protected since the crawl space is not accessable for storage.. .

Physically protected?
Since when is "storage" the only area that requires protection?

Someone is seriously out of their league and grasping at straws...
No offense, but this reeks of DIY.
 

Jim W in Tampa

Senior Member
Location
Tampa Florida
Re: #12 THHN cable assembly without a jacket.

hconant said:
Can THHN cable be run without a sheath or conduit? We need to install a new residential sub-panel from a crawl space to a new full basement. The branch circuits currently going to the old sub-panel need to be junctioned and relocated to the new sub-panel. We would like to get a cable assembly made of 15 #12 THHN wires, and two #6THHN (for the neutral and ground), then attach the assembly to the overhead joists in the crawl space where they will run to and into the new panel in the basement. I think this meets the requirement of being physically protected since the crawl space is not accessable for storage. We have also, on occasion run a single #14 THHN for smoke detector interface wire. Do these applications meet code?
Are you talking about MC ? Might be available but why not just run some 12-3
 

celtic

Senior Member
Location
NJ
Re: #12 THHN cable assembly without a jacket.

Jim W in Tampa said:
hconant said:
Can THHN cable be run without a sheath or conduit?
Are you talking about MC ? Might be available but why not just run some 12-3

I don't think they are talking about MC

[NOTE: hconant's post has been bolded by me]
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Jim,
Where would they even buy or order it from ?
You would get it a place like this, but it is not cost effective in short lengths. We have used a product like this for prison door locks. The locks required about 8 wires in 2 different sizes. We ordered the bundle with colors that matched the lock assembly pig tails. It can save a lot of time. It was installed in conduit and wire ways. We also often use a product like that with numbers on each wire for runs between between the DCS IO cards and field junction boxes.
Don
 

tonyi

Senior Member
Jim W in Tampa said:
Where would they even buy or order it from ?

Home made MC -- no joke, I saw some 3/8 flex with 3 #12 pulled through it being used to feed office recepticals at an IBM site. Two stranded and a green solid. I haven't a clue how they jammed it it, I couldn't get it out :lol:
 
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