Cables and Pneumatic hoses in E-Chain

[Slplsnts]

I am not sure this is the best place to ask this one, thank you for taking the time to look at this.
I am working on a machine in a hazardous location that requires motion. We have e-chains installed along with basket tray.
NEC 300.8 - Installation of conductors with other systems, does not allow other commodities such as pneumatic tubing to run in the same cable tray or raceway as conductors.
I have seen and installed many end effectors that had cables and pneumatics installed in e-chain or other conveyance on the arm. I am looking for anything in the NEC that actually allows this installation method. The machine I am working on is not an arm but does have motion that requires cables and pneumatic hoses to travel with the machine.

Does anyone have any guidance where I might find code that allows this?

I have used fuzzy logic that the term conductor isn't cable therefore doesn't apply to the installation since we are only running cables. I got some sideways looks since we can't find justification in Article 100 definitions to support that notion.

We have separators in the e-chain but they are not continuous.


Thank you for any thoughts on this.
Ken

 

[tom baker]

The NEC may not apply to your application wiring method, being it in a hazardous location wouldn’t it require some type of 3rd party listing? Those listing standards would dictate what’s allowed

 

[winnie]

The 'NEC' is also known as NFPA 70. It applies to the electrical wiring of a structure such as a home or factory building. Often this _standard_ is adopted as a legal code by local governments. Electricians generally know NFPA 70 as it applies to their jobs.

For designing an industrial machine, you should probably reference NFPA 79: https://www.nfpa.org/codes-and-stan...ds/list-of-codes-and-standards/detail?code=79 however it is possible that the relevant legal authority has adopted the corresponding standard from a different organization, or simply allows good engineering practice. I don't know (for example) what OSHA might require.

I should add that the legal requirements for industrial machine design is well outside my area of competence; I am just hoping I can point you in generally the correct direction.

-Jon

 

[Slplsnts]

Thank you for the replies. I had been looking through NFPA-79 but didn't find any verbiage either allowing or disallowing the mix of commodities with electrical.
The only code reference that had been stated is NEC 70, 300.8. We follow section 500 for hazardous locations and wiring methods etc. We also use NEC 70 for wiring and installation methods on machines where applicable.
Energy chain or motion doesn't appear to be directly addressed when referencing cables and tubing. At least that I can find so far.
I haven't looked at UL508A as of yet.

 

[retirede]

I’ve seen a lot of machinery that routed pneumatic and hydraulic lines along with power /control wiring in what you’re calling E-Chain.
However, none of those were used in classified areas.

 

[4-20mA]

I'm sure they sell the carrier chain with dividers. Would that suffice?

 

[Slplsnts]

I have also seen and designed many machines where there are cables routed with pneumatics through energy chain (E-Chain). Several manufacturers like IGUS have tools to help design the layout using dividers. Where the struggle is, NEC 70 section 300.8. The standards being used for Haz Loc are NEC 70, section 500 is applicable and it is now difficult what parts of standard wiring methods apply and don't apply to machines. NFPA - 79 does not have clear guidelines on the use of commodity with electrical conductors in a conveyance.
This seems to be accepted in practice but I can not find anything that would be a stated exception to NEC 70, 300.8 or a statement in NFPA-79 that allows the mix.

Thank you all for taking a look and offering advice.

 

[rbalex]

I have also seen and designed many machines where there are cables routed with pneumatics through energy chain (E-Chain). Several manufacturers like IGUS have tools to help design the layout using dividers. Where the struggle is, NEC 70 section 300.8. The standards being used for Haz Loc are NEC 70, section 500 is applicable and it is now difficult what parts of standard wiring methods apply and don't apply to machines. NFPA - 79 does not have clear guidelines on the use of commodity with electrical conductors in a conveyance.
This seems to be accepted in practice but I can not find anything that would be a stated exception to NEC 70, 300.8 or a statement in NFPA-79 that allows the mix.

Thank you all for taking a look and offering advice.

My "gut feeling" is that what you want to do is OK, especially in Class I, Division 2, but I can't offer an immediate direct answer from national standards.

For the time being, forget hazardous locations and concentrate on Section 300.8. First, consider how the installation would be acceptable in an ordinary location in the first place, i.e., a general-purpose application. The usual approval would be based on the assembly being certified by a NRTL - with or without installing the conductors with other systems. (Is the E-Chain even classified as a cable tray, or is it a support system?)

Then, consider the assembly in a classified location and apply Section 501.10(A)(2), or 501.10 B(2), and Section 501.140. I would give special attention to Section 500.140(B) concerning the cables.

Finally, apply Sec 500.8(A)

 

[petersonra]

The e-chains you speak of are not raceways so the prohibition found in the code about putting foreign systems in them does not apply.

 

[Slplsnts]

Hi Petersonra,

How does one determine the e-chain is/isn't a cable tray.

392.2 Definition. Cable Tray System. A unit or assembly of units or sections and associated fittings forming a structural system used to securely fasten or support cables and raceways.

This same definition in NFPA-79 points back to 392.2

Thank you,
Ken

 

[rbalex]

Petersonra is correct that e-chains aren't raceways. You are right in asking how we don't know they aren't cable trays, so Section 300.8 would still apply. My general answer to such a question would be, "How are they listed?", but cable trays aren't directly required to be listed by Article 392 - but See FedOSHA, 29 CFR 1910.399 definition of Acceptable. Read it carefully; the Subparts must be considered in sequence, i.e., 1910.399(a) takes precedence to 1910.399(b), which takes further precedence to 1910.399(c). In other words, if the product can be listed, it must be where FedOSHA has jurisdiction. In other jurisdictions, FedOSHA may still stick its nose in if a major incident occurs.

If it is a cable tray by Scope (Section 392.1) and/or definition (Section 392.2 or Article 100 depending on the NEC Edition) then every other detail of the Article must be adhered to.

This is why I suggested Section 500.8(A), particularly 500.8(A)(3). This Section more or less mirrors the 29.CFR 1910.399 definition of Acceptable. I have used it occasionally. If documented properly and accepted by a local jurisdiction. FedOSHA and most State OHSAs would also accept it.

I would give meticulous attention to the conductors/cables according to Section 501.140 or 501.141. That is, "extra-hard usage", integral EGC, sunlight resistance, etc.