Cable ties

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ernric43

Member
Location
United States
Are there any requirements for securing and supporting cables in a cable tray?
I'm looking at NEC 392.30 and it doesn't really provide any distance between ties.
I'm running 500MCM and 250MCM cables.

Thanks
Rich
 

Smart $

Esteemed Member
Location
Ohio
The distance maximum between points, if any, will be in the Article which covers the raceway or cable type, e.g. 336.10(7).
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
There are no specific requirements the cover the securing of single conductors to the tray. No securing is required for a horizontal cable tray run. Other that horizontal runs just require that the conductors be "fastened securely to transverse members of the cable runs". You your own good judgement, or check with your AHJ.
 

Smart $

Esteemed Member
Location
Ohio
There are no specific requirements the cover the securing of single conductors to the tray. No securing is required for a horizontal cable tray run. ...
That's not an absolute. :happysad:

Even single conductors must be a recognized and permitted cable wiring method in Chapter 3. Correlate that with the requirement of 392.30. Granted the cable tray itself is considered the means of support on horizontal runs, but it does not supersede any securing requirement. For example, the section I cited earlier [336.10(7)] requires Type TC cable in industrial facilities to be secured at intervals not exceeding 6ft.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
That's not an absolute. :happysad:

Even single conductors must be a recognized and permitted cable wiring method in Chapter 3. Correlate that with the requirement of 392.30. Granted the cable tray itself is considered the means of support on horizontal runs, but it does not supersede any securing requirement. For example, the section I cited earlier [336.10(7)] requires Type TC cable in industrial facilities to be secured at intervals not exceeding 6ft.
Show me the requirement for the securing of a 1/0 THWN conductor in a cable tray.
 

iwire

Moderator
Staff member
Location
Massachusetts

Smart $

Esteemed Member
Location
Ohio
392.10(B)(1)(a)?

When you consider this as well



http://www.southwire.com/ProductCatalog/XTEInterfaceServlet?contentKey=prodcatsheetOEM120

I assume Southwire knows to mark it for cable trays, I could certainly be wrong.

Most of the single conductors 1/0 and larger that I install in conduit are marked "CT" on the jacket.
I understand this, but what I'm eluding to is in regards to the first sentence of 392.10(B): "The wiring methods in Table 392.10(A) shall be permitted to be used in any industrial establishment under the conditions described in their respective articles."

Such conductors have to fall into one of the wiring methods of the Table. There's only one wiring method which has no article: "Other factory-assembled, multiconductor control, signal, or power cables that are specifically approved for installation in cable trays".
 

iwire

Moderator
Staff member
Location
Massachusetts
I understand this, but what I'm eluding to is in regards to the first sentence of 392.10(B): "The wiring methods in Table 392.10(A) shall be permitted to be used in any industrial establishment under the conditions described in their respective articles."

Such conductors have to fall into one of the wiring methods of the Table. There's only one wiring method which has no article: "Other factory-assembled, multiconductor control, signal, or power cables that are specifically approved for installation in cable trays".

So lets cut to the chase.

Do you really believe the NEC prohibits, or intends to prohibit single conductor in tray or are you just picking things apart for your entertainment?:D
 

Smart $

Esteemed Member
Location
Ohio
So lets cut to the chase.

Do you really believe the NEC prohibits, or intends to prohibit single conductor in tray or are you just picking things apart for your entertainment?:D
Neither... I'm just pursuing the requirement for securing cable to tray. I already pointed out the requirement which I believe applies.

And in regards to cutting to the chase, is your reply a cover for your not being able to resolve the dilemma? ;):angel:
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
I understand this, but what I'm eluding to is in regards to the first sentence of 392.10(B): "The wiring methods in Table 392.10(A) shall be permitted to be used in any industrial establishment under the conditions described in their respective articles."
...
You stopped reading the section too soon.
392.10(B) ... In industrial establishments only, where conditions of maintenance and supervision ensure that only qualified persons service the installed cable tray system, any of the cables in 392.10(B)(1) and (B)(2) shall be permitted to be installed in ladder, ventilated trough, solid bottom, or ventilated channel cable trays.
(B)(1) clearly permits the use of single conductor cables. There are no specific securing and supporting requirements in the NEC the cover the installation of single conductors 1/0 and larger in cable trays.
 

iwire

Moderator
Staff member
Location
Massachusetts
Neither... I'm just pursuing the requirement for securing cable to tray. I already pointed out the requirement which I believe applies.

And in regards to cutting to the chase, is your reply a cover for your not being able to resolve the dilemma? ;):angel:

I have no delima but I want to know if I am discussing something for real or if someone is arguing a point only for the sake of arguing.

IMO single conductors are allowed in cable tray. In the few areas that I work that have cable tray it is typical.

IMO you are being ridiculously literal in your interpretation of the sections.
 

Smart $

Esteemed Member
Location
Ohio
You stopped reading the section too soon.

(B)(1) clearly permits the use of single conductor cables. There are no specific securing and supporting requirements in the NEC the cover the installation of single conductors 1/0 and larger in cable trays.
Well I didn't stop reading to soon, I just posted the first sentence. Nonetheless, I was looking at the first sentence stipulation as inclusive of second sentence. The first sentence being a word-for-word repeat of 392.10(A) played a big factor. I now see it as an exemption to the first. :angel:
 

Smart $

Esteemed Member
Location
Ohio
I have no delima but I want to know if I am discussing something for real or if someone is arguing a point only for the sake of arguing.

IMO single conductors are allowed in cable tray. In the few areas that I work that have cable tray it is typical.

IMO you are being ridiculously literal in your interpretation of the sections.
Not contesting single conductors permitted in tray. I've actually installed 'em many times.

Not arguing for the sake of arguing, but I understand how you perceive it as such. Sometimes my thinking just needs a swift kick when I have preconceived notions on the requirements, and reading the sections again present a contradiction to those notions. I feel compelled to voice the contradiction... at times errantly as fact rather than expressing self doubt. It's a ugly side effect stemming from being in a position of leadership, having to at least appear decisive and knowledgeable to colleagues... while meek is my natural disposition.

Sometimes it takes several swift kicks to set my thinking straight... :slaphead:
 

Jgreagori

Member
Location
South Jersey
JGreagori Electrical inspector

JGreagori Electrical inspector

Cables in a horizontal run of cable tray do not require additional support or fastening in place 392.30. Where conductors and cables leave cable tray and may be free air they need support at minimum of every 6 ft and at point of exit to a raceway. Grouping of circuit conductors although is required 390.20 (C).
So therefore cable ty spacing should not be an issue as its not required.
 
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