Conductors/Cables passing though a cable tray (without entering the cable tray)

[ups_tx]

Can a conductor or cable pass through a cable tray without entering the cable tray (meaning, the conductors/cables do not run any length within the cable tray, merely pass through... drop through)?

I thought I read somewhere within the NEC this was not allowed, or am I going crazy? Maybe it was there in a past version, but now has been removed?

Thanks,

Usp_tx
NEC 2017, 2014, 2011 & 2008

 

[Dennis Alwon]

Cable trays in industrial establishments can have other cables and raceways attached to the bottom but it only talking about in parallel with the tray. Raceways on top of a tray could block the tray from being accessed easily, so my gut is the tray is not intended for raceway to pass thru it.

 

[petersonra]

I don't recall that it is prohibited so that suggests it is allowed. It is something that is done on a regular basis where two cable trays intersect at right angles. There is a pass through of those cables that continue in the same direction where the trays come together.

 

[ups_tx]

Let me explain a little more:

I have my LV SWGR feeders to the LV MCCs running near the ceiling @ ~9'-6" a.f.f. (18 total 500MCM), the customer wants me to run an instrument tray 1'-0" directly below the LV tray to facilitate the communication cables throughout the building.

I thought I had read where a conductor/cable cannot drop through another cable tray without being established within that tray, but regardless... there is physically no way I can drop 18, 500MCM cables (within a 36" tray) through an 18-24" tray and still have room for any type of communication cables. Not to mention, you don't want the electromagnetic fields from the feeder cable interfering with the communication signals either.

I just wanted to cite the code reference for the cable dropping through another cable tray if I could find it.

 

[petersonra]

Let me explain a little more:

I have my LV SWGR feeders to the LV MCCs running near the ceiling @ ~9'-6" a.f.f. (18 total 500MCM), the customer wants me to run an instrument tray 1'-0" directly below the LV tray to facilitate the communication cables throughout the building.

I thought I had read where a conductor/cable cannot drop through another cable tray without being established within that tray, but regardless... there is physically no way I can drop 18, 500MCM cables (within a 36" tray) through an 18-24" tray and still have room for any type of communication cables. Not to mention, you don't want the electromagnetic fields from the feeder cable interfering with the communication signals either.

I just wanted to cite the code reference for the cable dropping through another cable tray if I could find it.

I don't think there is one. And as a practical matter, running the LV wiring perpendicular to the comm cables reduces the potential for issues pretty dramatically.

However, the comm cables will be in the same cable tray with the LV wiring for a short distance and that would require they be separated by an appropriate barrier IMO.