Article 725 etc.

[mnandy]

Recently had a job inspected and it passed! In short the job was to convert old pneumatics control of multiple hvac units to ddc in a fairly big facility. I saw some things that I didn’t think would pass, pass. To make a long story short wires were strung across the ceiling grid and supported to the duct work all over the place with tie wraps and holes were drilled thru block walls and cables were pulled thru them (without sleeves). Some with fire caulk in them and some just pulled thru the drilled out holes (some of these penetrations may not have been firewalls so maybe that’s why they didn’t have fire caulk.. Job was not done in a neat and workman like manner. Oh and cables were taped to threaded rod. The only thing called out was some of the wiring laying on the grid which is spelled out pretty clear in 725. But anyways after digging through article 725 it seems like 725.3 throws out everything thing in article 300 and just references it here and there such as 300.4(d) and 300.22 and it does not clarify any of these issues for me. Basically what im getting out of this article is if it doesn’t say you cant do it, you can and as far as supporting you just need to support your cable to the structure with a listed strap etc referred in 725.24. All wire was plenum rated.

1. So I guess my question is can you straps cables to duct work some not so long and some for long stretches?
2. Can you run cables thru block walls without sleeves?
3. Can you tape cables to threaded rod?
4. Can you tie class 2 and 3 cables to ceiling grid wire (not independent wires)?It doesn’t say you can’t in 725
I guess I wouldn’t have done some of the things they did but it seems to me that other than laying wires on the grid somewhere there job was code I guess because not only did the inspector pass it but I cant find anything in the code saying anything they did was wrong. Looking for some opinions Thanks

 

[hbiss]

#1- Maybe. If your wiring is functionally related to the equipment on the duct I would say yes. Otherwise, though not specifically mentioned, you cannot use ductwork to support cabling.

#2- Yes, but it may require fire caulking.

#3- Wiring should be independently supported. Like #1, you can't hang it off other trades or their supports.

#4- See 300.11(A)(1) and (2) which 725 refers you back to.

-Hal

 

[mnandy]

Thanks Hal for your feedback!

Thanks Hal for your feedback!

Thanks for the feedback its nice to have another set of eyes on this. I have scoured this article recently because of this job. I would like to respond to a few of your thoughts.

1. agree with you on your thoughts on question 1! Nothing is specifically mentioned. The only thing that comes close is 725.133 (B) which refers you back to 300.22 (B) which in short just talks about wiring in ducts etc. It talks nothing about wiring outside of ducts. Was curious why the inspector said it was ok because it was functionally related to the equipment (maybe hes referring to this article?). But I can't find this anywhere except for this article and it is talking about inside and with it comes limitations.

p.s. just talked to the inspector on this and he finally agrees with me on this. all ties or supports to the ductwork will be removed!

2. agree with you on this too.

3. agree with you on this too. But after looking at 725.24 and 725.143 I don"t see anything saying it has to be independently supported just that it has to be supported by structural components of the building so the cable wont be damaged by normal building use.

4. Thanks for your feedback on this but I do not see anything that references me to the articles you referred (maybe I missed them) The only thing that refers you back to article 300 is 725.46 which is referring to class 1 cabling which im dealing with class 1 and 2. so back to class 1 and 2 circuit articles which are 725.24 and 725.143. These articles only refer me back to 300.11 (c) 2 and 300.4 (d). After looking at these they do not clarify any issues here. Maybe I missed something. So what I get out of this just tie to the building structure somehow etc.

Thanks curious on your thoughts!- hopefully this all makes sense

 

[jaggedben]

...

#3- Wiring should be independently supported. Like #1, you can't hang it off other trades or their supports.
...l

Is there a code section to back this up?

Say the plumber attached a bunch of struts to a wall to support a pipe, and there's plenty of extra space on the strut. I can't use the same strut to support a conduit?

 

[mnandy]

725.24

725.24

725.3- Circuits and equipment shall comply with articles or sections listed in 725.3(A) through (N). Only those sections of Article 300 referenced in this article shall apply to Class 1, Class 2, and Class 3 circuits.


725.24 Just says cables and conductors installed exposed on the surface of ceilings and sidewalls shall be supported by the building STRUCTURE in such a manner that the cable will not be damaged by normal building use. Such cables shall be supported by straps, staples, hangers, cable ties, or similar fittings designed and installed so as not to damage the cable. The installation shall also comply with 300.4 (d)

Article 100- Building- a structure that stands alone or that is separated from adjoining structure by firewalls.

Article 100- Structure- That which is built or constructed, other than equipment

I know I would hang my own independent support hangers but it seems like its open to tying to rod because there is nothing saying you cant. I'm forced to stay in article 725

 

[hbiss]

Is there a code section to back this up?

Say the plumber attached a bunch of struts to a wall to support a pipe, and there's plenty of extra space on the strut. I can't use the same strut to support a conduit?

I agree with you that the Code should make this clear. I think we went round and round with this once before. Can you ty-rap your cables to the sprinkler pipes or plumbing pipe? Reason being that the other trades can come in and change or remove their pipes or supports leaving your cables hanging. At the very least the cables could be in their way.

Suppose you hung a bunch of racks for your conduit. Would you be happy to see the plumber running his stuff on them? What happens if you needed to add another run in the future and now there is no room?

-Hal

 

[petersonra]

I agree with you that the Code should make this clear. I think we went round and round with this once before. Can you ty-rap your cables to the sprinkler pipes or plumbing pipe? Reason being that the other trades can come in and change or remove their pipes or supports leaving your cables hanging. At the very least the cables could be in their way.

Suppose you hung a bunch of racks for your conduit. Would you be happy to see the plumber running his stuff on them? What happens if you needed to add another run in the future and now there is no room?

-Hal

the code does not care at all about future changes or additions.

 

[jaggedben]

I agree with you that the Code should make this clear. I think we went round and round with this once before. Can you ty-rap your cables to the sprinkler pipes or plumbing pipe? Reason being that the other trades can come in and change or remove their pipes or supports leaving your cables hanging. At the very least the cables could be in their way.

I think there's a pretty clear difference between attaching to another trade's pipes and attaching to something they attached to when the latter is a method our trade would readily use.

Suppose you hung a bunch of racks for your conduit. Would you be happy to see the plumber running his stuff on them? What happens if you needed to add another run in the future and now there is no room?

-Hal

I suppose my reaction would depend on all sorts of details, such as whether I was still working on the job or finished it 10 years ago, whether I put in extra strut to plan for the future or because something about the building forced me to, etc. etc..

 

[hbiss]

Ok, so what's the answer here? I'm not seeing anything in the Code that would prohibit me from hanging my stuff off sprinkler pipes, plumbing or in this case duct work.

Only thing I do see is that we can't hang it off our own conduit- which I interpret to mean any of those other things above too..

-Hal

 

[don_resqcapt19]

Ok, so what's the answer here? I'm not seeing anything in the Code that would prohibit me from hanging my stuff off sprinkler pipes, plumbing or in this case duct work.

Only thing I do see is that we can't hang it off our own conduit- which I interpret to mean any of those other things above too..

-Hal

Hanging off that other stuff is not a violation of the NEC, but it may be a violation of other codes. I know that NFPA 13 does not permit fire sprinkler pipes to be used as a support for anything.

 

[mnandy]

I agree with you that the Code should make this clear. I think we went round and round with this once before. Can you ty-rap your cables to the sprinkler pipes or plumbing pipe? Reason being that the other trades can come in and change or remove their pipes or supports leaving your cables hanging. At the very least the cables could be in their way.

Suppose you hung a bunch of racks for your conduit. Would you be happy to see the plumber running his stuff on them? What happens if you needed to add another run in the future and now there is no room?

-Hal

Thanks Hal- The only thing that comes close to saying anything about this is 725.3 (K) which refers you to 300.8 which still does not specifically say you can't, it just says Raceways or cabletrays containing electrical conductors shall not contain any pipe, tube, or equal for steam, water, air, gas, drainage, or any service other than electrical.

But in my argument saying you can't I would have to refer back to 725.24 where it says cables and conductors installed exposed on the surface of ceilings and sidewalls shall be supported by the building STRUCTURE in such a manner that the cable will not be damaged by normal building use. Such cables shall be supported by straps, staples, hangers, cable ties, or similar fittings designed and installed so as not to damage the cable. The installation shall also comply with 300.4 (d)


1. sprinkler pipes and plumbing pipes are not designed to support cables
2. plus pipes are not structure

Thanks Andrew