Dave F
Member
- Location
- Ventrura, CA
I sent in this question awhile ago,
Are there any provisions for double stacking multi-conductor MC aluminum feeders in a steel ladder type cable tray? I only have enough room to install a 4' wide x 6" tall cable tray but I have more cables than the code will allow me to install in a single layer. I'm wondering if there are any provisions when I could place a spacer between each layer which would allow air flow and cooling of the multi-conductor cable.
I received an answer from a senior member. He gave me a link to a Panduit product -http://www.panduit.com/products/Prod...ins/069134.pdf - now I have another question:
Because 392.9 A1 addresses the fill and says that they must not exceed the width of the tray and they shall be installed in a single layer. That was my first challenge because I need to install multiple layers with in the tray.
Then if you go to 392.11 the code addresses ampacity.The feeder cables I need to install are 3 conductor (MC) and are either 4/0 aluminum or larger. But it seems that 392.11 A3 is requiring that I install no more than one layer AND have not less than one cable diameter clearance between each cable. I read in a sales brochure from CABLOFIL that 392.11 A1 would not apply to my installation because I am under the 4 conductor rule for derating. They also state that 392.11 A3 is "not a limitation, as this provision allows a HIGHER ampacity if you install conductors in a single layer and space them. It is not a code requirement to place multi-conductors in a single layer spaced one diameter apart."
How do the 'Panduit Cable Rack Spacers' get me past this hurdles?
Are there any provisions for double stacking multi-conductor MC aluminum feeders in a steel ladder type cable tray? I only have enough room to install a 4' wide x 6" tall cable tray but I have more cables than the code will allow me to install in a single layer. I'm wondering if there are any provisions when I could place a spacer between each layer which would allow air flow and cooling of the multi-conductor cable.
I received an answer from a senior member. He gave me a link to a Panduit product -http://www.panduit.com/products/Prod...ins/069134.pdf - now I have another question:
Because 392.9 A1 addresses the fill and says that they must not exceed the width of the tray and they shall be installed in a single layer. That was my first challenge because I need to install multiple layers with in the tray.
Then if you go to 392.11 the code addresses ampacity.The feeder cables I need to install are 3 conductor (MC) and are either 4/0 aluminum or larger. But it seems that 392.11 A3 is requiring that I install no more than one layer AND have not less than one cable diameter clearance between each cable. I read in a sales brochure from CABLOFIL that 392.11 A1 would not apply to my installation because I am under the 4 conductor rule for derating. They also state that 392.11 A3 is "not a limitation, as this provision allows a HIGHER ampacity if you install conductors in a single layer and space them. It is not a code requirement to place multi-conductors in a single layer spaced one diameter apart."
How do the 'Panduit Cable Rack Spacers' get me past this hurdles?