Supporting cable tray with cable tray.

[No1BroncoFan]

Is it ever permissible to support one cable tray run with another or should they (as I've been taught) utilize only their own support? Is there any relevant code addressing this?

Thanks,
Ben

 

[Fnewman]

Not sure exactly what arrangement you are suggesting (a sketch or photo would help). Other code issues aside, for sure the support has to be in accordance with the manufacturer's instructions, so a call to their support desk might be helpful.

 

[Smart $]

Is it ever permissible to support one cable tray run with another or should they (as I've been taught) utilize only their own support? Is there any relevant code addressing this?

Thanks,
Ben

I've run as many as five runs of 6" x 36" steel cable tray on the same trapezes.

I'm with Fnewman. Please provide more details of what you are wanting to do.

 

[Fulthrotl]

Is it ever permissible to support one cable tray run with another or should they (as I've been taught) utilize only their own support? Is there any relevant code addressing this?

Thanks,
Ben

as others have mentioned, multiple trays on a tiered trapeze is common. how many lbs/ft
are you running?

as a second year apprentice, i watched a "journeyman" use 1/4" running thread to support
a trapeze with 18" tray with parallel *copper* 500 MCM's feeding gear.

the anchors were drive in wedge. after a couple months, one of them popped, creating
a zipper effect, and dropping the whole rack onto an electronics lab, in the middle of
the night. nobody was there at the time.

it made a mess.

1/2" running thread, properly attached to the overhead, on 8' centers, will carry an
awful lot of weight.

 

[No1BroncoFan]

I've run as many as five runs of 6" x 36" steel cable tray on the same trapezes.

I'm with Fnewman. Please provide more details of what you are wanting to do.

It's not what I'm wanting to do. It's what the engineer wants to do...

He wants to drop a 90deg vertical bend into a horizontal tray below, supporting the 90deg vertical bend with the tray below at about mid-span. No other support on that end of the bend despite B-Line and NEMA VE 2-2000 both requiring it.

 

[Smart $]

A lot depends on how much weight is going to be added to the tray. Can't tell by the wireframe render.

I can't see where B-Line's cable tray manual requires any particular support placement, and NEMA VE-2* uses the term "should" to say support is recommended at each end of the vertical elbow.

The transition at the bottom isn't pretty, but it's nothing I haven't seen before. The engineer leaves no means to splice the trays together at the bottom of the "dump". No mechanical or electrical bond. Under the NEC that's loosely jointed and will require at the very least a bonding jumper.

I say install it per design. You have the proof that is how the engineer wants it. Have you RFI'd the EE?


*A newer version of NEMA VE-2 is available from their website: https://www.nema.org/Standards/ComplimentaryDocuments/NEMA VE 2-2013 ERRATA.pdf



:thumbsup: BTW, welcome to the forum. :thumbsup:

 

[No1BroncoFan]

A lot depends on how much weight is going to be added to the tray. Can't tell by the wireframe render.

I can't see where B-Line's cable tray manual requires any particular support placement, and NEMA VE-2* uses the term "should" to say support is recommended at each end of the vertical elbow.

The transition at the bottom isn't pretty, but it's nothing I haven't seen before. The engineer leaves no means to splice the trays together at the bottom of the "dump". No mechanical or electrical bond. Under the NEC that's loosely jointed and will require at the very least a bonding jumper.

I say install it per design. You have the proof that is how the engineer wants it. Have you RFI'd the EE?


*A newer version of NEMA VE-2 is available from their website: https://www.nema.org/Standards/ComplimentaryDocuments/NEMA VE 2-2013 ERRATA.pdf



:thumbsup: BTW, welcome to the forum. :thumbsup:

After further discussion (read, headbutting), the design is changing to accommodate support at all points and the removal of the tray bend. If we were putting this design in Santa Monica I'd be more sanguine about it. It's going in Weld County Co. so there will be plenty of environmental loading, high winds, heavy snow, usually together, and that left me concerned as the designer whose name is going on the drawings... Pretty has rarely concerned me. Functionality however...

Anyhow, thanks to those who replied and thanks for the welcome. I'll try not to be that guy who pops up once, asks a question and disappears again.