Cable Trays -- 392 & 725

[tryinghard]

I?ve been looking through Articles 392 & 725 and I am wondering can signal tray cable be supported in 6? intervals as bundled 4 or 6 cables or does each individual cable require support every 6??

 

[Smart $]

I’ve been looking through Articles 392 & 725 and I am wondering can signal tray cable be supported in 6’ intervals as bundled 4 or 6 cables or does each individual cable require support every 6’?

In horizontal runs, the tray itself is the support. In other than horizontal runs 392.8(B) stipulates the cables shall be fastened securely to transverse members of the cable tray. There are no other specifics that I'm aware of.

I've yet to see every cable fastened securely to every cross member in vertical runs and have never been or heard of anyone getting tagged for not doing so.

If doubt exists, I suggest contacting the AHJ for an interpretation...

 

[tryinghard]

In horizontal runs, the tray itself is the support. In other than horizontal runs 392.8(B) stipulates the cables shall be fastened securely to transverse members of the cable tray. There are no other specifics that I'm aware of....

Thanks; I see 392.8(B) but notice 336.10(6) Tray Cable, Installation, Uses Permitted:
?The cable shall be secured at intervals not exceeding 6??.

In my past I?ve bundled and tied and I really don?t see a problem with this but now a question has come up about bundling as opposed to supporting individually. Actually this is for a municipal and so I will also be the AHJ and as always I want to install it correctly.

Any other thoughts? Anyone?

 

[Rockyd]

About every forth rung seems to be about the norm. Ty wraps at entry and exits, Keep it reasonably clean, and it is a lot easier when trouble shooting.

My reference is in regaurd to tray sith side walls, and 9" spacing of rails.

 

[Rockyd]

Only bundling I've seen required was individual conductors of a three phase feeder bundled together for induction. see 392.11(B)

 

[Smart $]

Thanks; I see 392.8(B) but notice 336.10(6) Tray Cable, Installation, Uses Permitted:
?The cable shall be secured at intervals not exceeding 6??.

What version of the NEC are you using? The 2005 version has has 8 uses permitted listed under 336.10. Items 1, 6, and 8 remain unchanged from previous cycle and #6 is regarding fire alrm cirucits. The only mention of being secured every 6' is within #7, which begins "In industrial establishments..." (Is this installation in an industrial establishment?) and the requirement therein is for securing Type TC-ER cable between the tray and utilization equipment.

...Actually this is for a municipal and so I will also be the AHJ...

So getting an AHJ interpretation shouldn't be too difficult :grin:

 

[tryinghard]

What version of the NEC are you using?

Well; 2005 at work and at home I have 2002 handy, your right about note (6) changing to (7) between these versions. All-in-all though I guess I should or can fasten to the tray in regular intervals, to keep it orderly, but it seems I'm not required to. I guess I can also bundle the control cables as well if I chose to.

So getting an AHJ interpretation shouldn't be too difficult :grin:

This is an industrial application as well as a municipal and your right again the AHJ, even though he's picky, can be bias with me :grin:

Thanks guy's

 

[benaround]

TH,

" cables shall be secured at intervals not exceeding 6' " My thinking would be

bundled or not as long as they are secured you are meeting the requirement!