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Posted By: ggardiner nec2002 250.118 - 11/08/01 10:50 PM
Can anyone tell me what are the listed cables with acceptable ground return paths are. As it is referred to in 517.13.
Haven't received my copy of 2002 yet and I have to plan installations for the year year.
Posted By: electure Re: nec2002 250.118 - 11/11/01 01:23 PM
The Code does not list cables as being approved or not. It only (517.13) requires that:
"The metal raceway system, or cable armor, or sheath assembly shall itself qualify as an equipment grounding return path in accordance with 250.118."
The cable's listing is what will determine its acceptability
Although they mention A/C, M/C, & M/I cable, the only one I know of is A/C for your useage.
This is nearly a repeat of the Q you already asked in another section of the BB.
Check there [Linked Image]

[This message has been edited by electure (edited 11-11-2001).]
Posted By: Joe Tedesco Re: nec2002 250.118 - 11/11/01 02:04 PM
2002 NEC 250.118 (11) Type MC cable where listed and identified for grounding in accordance with the following:

a. The combined metallic sheath and grounding conductor of interlocked metal tape type MC cable

b. The metallic sheath or the combined metallic sheath and grounding conductors of the smooth or corrugated tube type MC cable


[This message has been edited by Joe Tedesco (edited 11-11-2001).]
Posted By: sparky Re: nec2002 250.118 - 11/11/01 02:06 PM
lemme see,
the only real 250.118 change in 02' is 250.118(1)
A copper, aluminum, or copper clad aluminum conductor.......
[Linked Image]
Posted By: electure Re: nec2002 250.118 - 11/11/01 02:53 PM
Be sure to check with the local AHJ as to what edition of the Code they are using before you incorporate any 2002 changes.
Many of them in my area are still basing everything on the '96 Code!
Posted By: resqcapt19 Re: nec2002 250.118 - 11/11/01 04:35 PM
Joe,
Just so everyone understands, the combined metallic sheath and the grounding conductor of the interlocking armor type MC cable does not meet the requirement in 517.13.
don(resqcapt19)
Posted By: Joe Tedesco Re: nec2002 250.118 - 11/11/01 08:58 PM
Here is the exact reference from the new 2002 NEC. What part of this is not clear or understood?

[Linked Image]

And here is what the 2002 NEC says in 250.118 (11) Type MC cable where listed and identified for grounding in accordance with the following:
a. The combined metallic sheath and grounding conductor of interlocked metal tape type MC cable

b. The metallic sheath or the combined metallic sheath and grounding conductors of the smooth or corrugated tube type MC cable




[This message has been edited by Joe Tedesco (edited 11-11-2001).]
Posted By: resqcapt19 Re: nec2002 250.118 - 11/11/01 09:17 PM
Joe,
My point is that MC cable that is listed as an EGC per 250.118(11)(a) is not suitable for 517.13 installations because the sheath istself does not qualify as an EGC. It only qualifies when combined with the internal grounding conductor, and therefore does not meet the requirements of 517.13.
Don(resqcapt19)
Posted By: electure Re: nec2002 250.118 - 11/11/01 10:29 PM
Joe,
Do you know a company that has type MC or MI Cable that meets the requirements? (Come on, now!) What part don't you understand?
My concern is that if Mr Gardiner specs a freak, it will be a long lead-time item, and will not be acceptable when his EC gets it.
Use AFC's type AC-HCF (as Nick said) or an approved equal, and you can put it to bed.
Posted By: Joe Tedesco Re: nec2002 250.118 - 11/11/01 11:15 PM
Look here:

http://www.afcweb.com/table2.html
http://www.afcweb.com/fieldhcf.htm

Seems like MC cable is also approved for Fire Alarms.



[This message has been edited by Joe Tedesco (edited 11-11-2001).]
Posted By: resqcapt19 Re: nec2002 250.118 - 11/12/01 03:17 AM
Joe,
The sites that you list in your post do not say that their type MC cable can be used for power circuits in 517.13 locations. The cables listed for use for power are type AC cables and I agree that type AC is acceptable as long as there is an EGC within the cable. The sheath of type AC cable is suitable in itself for use as an equipment grounding conductor. The only type of MC cable that could be used in these locations is the corrugated or smooth sheathed types, as the outer sheath of these types of MC cable are EGCs. The outer sheath of the interlocking armor type of MC cable is not in itself an EGC and cannot be used in these locations.
Don(resqcapt19)
Posted By: Bill Addiss Re: nec2002 250.118 - 11/12/01 03:23 AM
Joe,

There is a parallel thread running on this same question. (probably something We should try to avoid in the Future)
https://www.electrical-contractor.net/ubb/Forum2/HTML/000328.html


Bill
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