Secure and Support

[brother]

Been doing some surfing and was reading of the code questions someone had about cable ties on mc cable. What do you think of the response to the question. Nec doesnt really define 'secure' or 'support'.

Question 1. I seem to be frequently involved in discussions over the use of cable ties as a supporting means for metal-clad cable. Section 330.30 doesn?t clearly state that cable ties can be used as a support method. I am aware that cable ties are clearly defined as an approved method in the following Code locations: 320.30, 334.30, 338.10(B)(b), and 340.10(4). Could you give us your take on this subject? ? G.C.


Answer 1. Article 330.30 of NEC 2002 requires Type MC cable to be supported and secured at intervals not exceeding 1.8 m (6 ft). Article 300.11 also applies and requires cable assemblies to be securely fastened in place. Article 320.30 allows cable ties to be used to secure type AC cable and does not allow cable ties to be used to support type AC cable. Articles 334.30, 338.10(B)(4)(b), and 340.10(4) also reference cable ties for securing but not for supporting cables. Cable ties are specifically mentioned in 2002 Code articles for securing cable type wiring methods but not as the supporting means. ? Gaylen Rogers, CMP-17

 

[iwire]

What do you think of the response to the question.

I think it is meaningless, Gaylen Rogers interpretation is no more official then yours or mine.

BTW, I think you should say or link to where it came from.

 

[brother]

I think it is meaningless, Gaylen Rogers interpretation is no more official then yours or mine.

BTW, I think you should say or link to where it came from.

this is the link. Im sure some inspectors here have heard of IAEI . this is their magazine article.

http://magazine.iaei.org/foc/cmp17.htm#q1

 

[iwire]

Im sure some inspectors here have heard of IAEI .

I have never heard of it can you fill me in? :roll:

Without you telling us where the quote came from how would we know?

It could have been IAEI, EC&M, at a code seminar etc.


Anyway..... ultimately it ends up being the local inspectors decision if a cable tie is securing or supporting or if they even care.

Where I work cable ties are used extensively for the installation if MC.

 

[roger]

Same here, as well as tie wire.


Roger

 

[Jim W in Tampa]

I would prefer tie wire.We all know that in a hot wearhouse after many years them plastic straps get brittle.

 

[peter d]

I would prefer tie wire.We all know that in a hot wearhouse after many years them plastic straps get brittle.

True, they do get brittle, but unless someone is up there tugging on the cables, they aren't going anywhere. I've demoed plenty of tiewraps that were 20+ years old that were still in good shape.

 

[nakulak]

I have mixed feelings about the cable ties. Some of that alum mc is so easy to damage I wonder if tie wire is overdoing it.

 

[cowboyjwc]

While I agree with Jim I also agree with Peter, but I also believe that if we weren't worried about people tugging on them then we wouldn't have to secure them.

 

[Geoffrey Lyons]

So if cable is atop and cable tie is used its secured if below with cable tie its supported ie on a bar joist install? What is tie wire is it same as mechanics or bailing wire?

 

[Jim W in Tampa]

There is a crossover between time and cost as to which to pick.My concern with plastic is they really cant take much weight safely,now if they are laying on top of beams then really no problem if they let go.If they actually are holding a run of 12-4 for 50 feet we might have a problem but not till warrany is out.