nm cable in raceway
- Thread starter ldbelec
- Start date
- Status
- Location
- Illinois
- Occupation
- retired electrician
Re: nm cable in raceway
NM is not suitable for wet locations.
Don
NM is not suitable for wet locations.
Don
electricman2
Senior Member
- Location
- North Carolina
- Occupation
- Retired Electrical Contractor
Re: nm cable in raceway
Use UF
Use UF
bphgravity
Senior Member
- Location
- Florida
Re: nm cable in raceway
UF isn't permitted in a raceway, use an insulated conductor as specified in Section 310.8(C).
UF isn't permitted in a raceway, use an insulated conductor as specified in Section 310.8(C).
jtester
Senior Member
- Location
- Las Cruces N.M.
Re: nm cable in raceway
Bryan
I always thought that UF was suitable for installation in a raceway, but I have heard arguments otherwise. In the 2005, it seems that it is required sometimes. 340.10(4) allows it to be installed as NM cable. 334.12(B) requires NM cable exposed to damage to be installed in conduit.
Jim T
Bryan
I always thought that UF was suitable for installation in a raceway, but I have heard arguments otherwise. In the 2005, it seems that it is required sometimes. 340.10(4) allows it to be installed as NM cable. 334.12(B) requires NM cable exposed to damage to be installed in conduit.
Jim T
physis
Senior Member
Re: nm cable in raceway
This is from Article 340 on UF.
340.10(4)Installed as nonmetalic-sheathed cable. Where so installed, the installation and conductor requirements shall comply with the provisions of Article 334 and shall be of the multiconductor type.
Looks like UF can be used as NM.
For conduit fill the largest dimension of the cable must be considered as a diameter.
Edit: I don't always spell so good.
[ December 20, 2004, 12:36 PM: Message edited by: physis ]
This is from Article 340 on UF.
340.10(4)Installed as nonmetalic-sheathed cable. Where so installed, the installation and conductor requirements shall comply with the provisions of Article 334 and shall be of the multiconductor type.
Looks like UF can be used as NM.
For conduit fill the largest dimension of the cable must be considered as a diameter.
Edit: I don't always spell so good.
[ December 20, 2004, 12:36 PM: Message edited by: physis ]
bphgravity
Senior Member
- Location
- Florida
Re: nm cable in raceway
UF being used as NM cable cannot be installed in a raceway either. At least not per the 2002 NEC. The cables are permitted per the 2005 NEC. Protection is a different issue. At least not per the 2002 NEC. The cables are permitted per the 2005 NEC.
UF being used as NM cable cannot be installed in a raceway either. At least not per the 2002 NEC. The cables are permitted per the 2005 NEC. Protection is a different issue. At least not per the 2002 NEC. The cables are permitted per the 2005 NEC.
Re: nm cable in raceway
There is nothing wrong with UF in a raceway.
If it is questioned, just don't terminate the PVC in an enclosure, therefore you will not have a conduit system, but simply a sleeve for protection, or, you can wait until jan 1 05 (if your area adopts it) and it being allowed is finally in specific wording.
See 342.22 thru 362.22 and 388.22
BTW, there is nothing in the 02 prohibiting it, if it were prohibited, note 9 in the Notes to Tables in Chapter 9 would be wasted ink.
Roger
[ December 20, 2004, 12:54 PM: Message edited by: roger ]
There is nothing wrong with UF in a raceway.
If it is questioned, just don't terminate the PVC in an enclosure, therefore you will not have a conduit system, but simply a sleeve for protection, or, you can wait until jan 1 05 (if your area adopts it) and it being allowed is finally in specific wording.
See 342.22 thru 362.22 and 388.22
BTW, there is nothing in the 02 prohibiting it, if it were prohibited, note 9 in the Notes to Tables in Chapter 9 would be wasted ink.
Roger
[ December 20, 2004, 12:54 PM: Message edited by: roger ]
websparky
Senior Member
- Location
- Cleveland, Ohio
Re: nm cable in raceway
Brian,
You should have kept reading a little farther down the page!
[ December 20, 2004, 12:53 PM: Message edited by: websparky ]
Brian,
You should have kept reading a little farther down the page!
[ December 20, 2004, 12:53 PM: Message edited by: websparky ]
hbiss
EC, New York NEC: 2017
- Location
- Little Falls, New York NEC: 2017
- Occupation
- EC
Re: nm cable in raceway
UF isn't permitted in a raceway...
Ok, then what do you do where direct buried UF emerges from the ground and enters the building? I have always used PVC and an LB and I can't see where that is prohibited.
-Hal
UF isn't permitted in a raceway...
Ok, then what do you do where direct buried UF emerges from the ground and enters the building? I have always used PVC and an LB and I can't see where that is prohibited.
-Hal
peter d
Senior Member
- Location
- New England
Re: nm cable in raceway
For the sake of argument, what is the safety hazard of using a cable assembly inside of a raceway?
I have heard the "It's not secured" argument, but single conductors inside of a raceway aren't secured either.
For the sake of argument, what is the safety hazard of using a cable assembly inside of a raceway?
I have heard the "It's not secured" argument, but single conductors inside of a raceway aren't secured either.
paul
Senior Member
- Location
- Snohomish, WA
Re: nm cable in raceway
Since 340.10(4) allows UF to be installed as NM we can use article 334.
2005 NEC ---
334.15 (B) Protection from Physical Damage.
Cable shall be protected from physical damage where necessary by rigid metal conduit, intermediate metal conduit, electrical metallic tubing, Schedule 80 PVC rigid nonmetallic conduit, or other approved means. Where passing through a floor, the cable shall be enclosed in rigid metal conduit, intermediate metal conduit, electrical metallic tubing, Schedule 80 PVC rigid nonmetallic conduit, or other approved means extending at least 150 mm (6 in.) above the floor.
Or...to avoid all the hoopla and a possible red tag, pull in some THHN conductors and call it good.
Since 340.10(4) allows UF to be installed as NM we can use article 334.
2005 NEC ---
334.15 (B) Protection from Physical Damage.
Cable shall be protected from physical damage where necessary by rigid metal conduit, intermediate metal conduit, electrical metallic tubing, Schedule 80 PVC rigid nonmetallic conduit, or other approved means. Where passing through a floor, the cable shall be enclosed in rigid metal conduit, intermediate metal conduit, electrical metallic tubing, Schedule 80 PVC rigid nonmetallic conduit, or other approved means extending at least 150 mm (6 in.) above the floor.
Or...to avoid all the hoopla and a possible red tag, pull in some THHN conductors and call it good.
bphgravity
Senior Member
- Location
- Florida
Re: nm cable in raceway
Hal, what you describle is protection from physical damage. I clearly stated that is another issue.
Dave, nothing in what you posted indicates NM or UF can be installed in a raceway.
Tell me why Type MV, MC, and TC specifically list "in raceways" as uses permitted, yet none of the other cable sections do?
Look at the sections Roger listed. The XXX.22 ones. "Cables shall be permitted to be installed where such use is permitted by the respective cable articles." I see only three permitting it.
Using a piece of conduit to sleeve a cable is not the same as a raceway joining enclosures with a cable pulled through in place of individual conductors.
With that said, I install NM and UF in raceways all the time and see no hazard doing so.
[ December 20, 2004, 04:54 PM: Message edited by: bphgravity ]
Hal, what you describle is protection from physical damage. I clearly stated that is another issue.
Dave, nothing in what you posted indicates NM or UF can be installed in a raceway.
Tell me why Type MV, MC, and TC specifically list "in raceways" as uses permitted, yet none of the other cable sections do?
Look at the sections Roger listed. The XXX.22 ones. "Cables shall be permitted to be installed where such use is permitted by the respective cable articles." I see only three permitting it.
Using a piece of conduit to sleeve a cable is not the same as a raceway joining enclosures with a cable pulled through in place of individual conductors.
With that said, I install NM and UF in raceways all the time and see no hazard doing so.
[ December 20, 2004, 04:54 PM: Message edited by: bphgravity ]
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- Semi-retired engineer
Re: nm cable in raceway
I suspect that some of these prohibitions come from manufacturers of raceways and representatives of unions wanting to restrict the use of cable assemblys. I agree there is no obvious reason why one could not install NM cable inside a conduit of some sort, and in some cases it makes a lot od sense to do so.
I suspect that some of these prohibitions come from manufacturers of raceways and representatives of unions wanting to restrict the use of cable assemblys. I agree there is no obvious reason why one could not install NM cable inside a conduit of some sort, and in some cases it makes a lot od sense to do so.
pierre
Senior Member
- Location
- Westchester County, New York
Re: nm cable in raceway
One of the considerations to account for when installing cable types inside of raceways is heat dissipation.
Another is damage to the cable/conductors in the process of installing the cable in the raceway.
In the 2002, there was miscommunication between the different CMPs, in the 2005 see 352.12(E)Exception:.
I do not see any direct problems, as long as the raceway is sized properly.
Pierre
[ December 20, 2004, 05:35 PM: Message edited by: pierre ]
One of the considerations to account for when installing cable types inside of raceways is heat dissipation.
Another is damage to the cable/conductors in the process of installing the cable in the raceway.
In the 2002, there was miscommunication between the different CMPs, in the 2005 see 352.12(E)Exception:.
I do not see any direct problems, as long as the raceway is sized properly.
Pierre
[ December 20, 2004, 05:35 PM: Message edited by: pierre ]
websparky
Senior Member
- Location
- Cleveland, Ohio
Re: nm cable in raceway
Brian,
Brian,
Maybe you missed that 300 applies to ALL wiring methods?
And maybe you missed some of Roger's post?
bphgravity
Senior Member
- Location
- Florida
Re: nm cable in raceway
Maybe you guys should read my posts a little more clearly? I stated in my second post that the 2005 has made the allowance for cables in raceways. My quote is from the 2002. :roll:
Dave, I'm quite familiar with the scope of Chapter 3. The Chapter 9 Notes refer to the three cabling methods permitted to be installed in raceways.
The IAEI analysis expalains this clearly.
[ December 20, 2004, 06:42 PM: Message edited by: bphgravity ]
Maybe you guys should read my posts a little more clearly? I stated in my second post that the 2005 has made the allowance for cables in raceways. My quote is from the 2002. :roll:
Dave, I'm quite familiar with the scope of Chapter 3. The Chapter 9 Notes refer to the three cabling methods permitted to be installed in raceways.
The IAEI analysis expalains this clearly.
[ December 20, 2004, 06:42 PM: Message edited by: bphgravity ]
bphgravity
Senior Member
- Location
- Florida
Re: nm cable in raceway
I still find it interesting that the three mentioned cable sections specifically list "in raceways" under uses permitted, while it does not for all the others.
I think having a section for both permitted and not permitted creates the confusion. At one point I believe it was planned to drop one of the sections so that the article became specifcally permissive or prohibitive instead of both.
I mean really, why would they specify that type AC is permitted in cable trays but nothing about raceway, where the similar method of type MC does?
I look forward to puting this issue to rest once the 2002 goes back on the bookshelf. I'm sure we will find another one of these "could go either way" topics for the 2005.
I still find it interesting that the three mentioned cable sections specifically list "in raceways" under uses permitted, while it does not for all the others.
I think having a section for both permitted and not permitted creates the confusion. At one point I believe it was planned to drop one of the sections so that the article became specifcally permissive or prohibitive instead of both.
I mean really, why would they specify that type AC is permitted in cable trays but nothing about raceway, where the similar method of type MC does?
I look forward to puting this issue to rest once the 2002 goes back on the bookshelf. I'm sure we will find another one of these "could go either way" topics for the 2005.
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