CABLE TRAY SIZING FLOWCHART
Start
Sizing Cable Tray Per NEC 392
Here
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| 392.12 |
|
| No | 2000V |
|
| |||||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| W ≥ Sd |
|
|
|
|
|
| or less |
|
| ||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |||||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| (single layer) |
|
|
|
|
|
| cables |
|
| |||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Yes |
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| ||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| ||
Solid | No | Vented |
| No |
|
|
| Ladder | Yes |
|
|
|
|
|
| No |
|
|
| Yes | ||||||||||
|
|
|
|
| S/C 1/0 |
|
| Multi- | ||||||||||||||||||||||
Bottom |
|
| Channel |
|
|
|
|
| or Vented |
|
|
|
|
|
|
|
| conductor |
|
|
| |||||||||
|
|
|
|
|
|
| Trough |
|
|
| or larger |
|
|
|
|
|
|
|
| |||||||||||
Tray |
|
| Tray |
|
|
|
|
|
|
|
|
|
|
|
|
| cables |
|
| |||||||||||
|
|
|
|
|
|
| Tray |
|
|
|
|
|
|
|
|
|
|
|
|
| ||||||||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Continued | |||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| ||||
| Yes |
|
|
| Yes |
|
|
|
|
|
| Yes |
|
|
|
|
|
|
|
|
|
|
|
| on | next | ||||
|
|
|
|
|
|
|
|
|
|
|
|
|
| No |
|
|
|
|
|
|
| page | ||||||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| S/C |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |||
392.10 |
|
|
|
|
|
|
|
| Yes |
|
|
| 392.3(B)(1)(a) |
|
|
|
|
|
|
|
|
| ||||||||
|
|
| 392.10(B) |
|
| 392.10(A)(1) |
|
|
|
|
|
|
|
|
|
|
|
| ||||||||||||
Not |
|
|
|
|
| 1000 |
|
|
|
|
|
|
|
|
|
|
|
| ||||||||||||
|
|
|
|
|
|
|
| Not permitted |
|
|
|
|
|
|
|
|
| |||||||||||||
recognized by |
|
|
| W ≥ Sd |
|
| W ≥ Sd |
|
|
| kcmil or |
|
|
|
|
|
|
|
|
|
|
|
| |||||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| ||||||||||||
|
|
|
|
|
|
|
|
|
|
| by the NEC | ® |
|
|
|
|
|
|
|
|
| |||||||||
the NEC® |
|
|
|
|
|
|
|
|
|
|
| larger |
|
|
|
|
|
|
|
|
|
|
|
|
| |||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
No
Note: The value “A” only applies to cables 250 up to 1000kcmil.
The value “sd” only
applies to 1000 kcmil
and larger cables.
Legend
W = Cable Tray Width
D = Cable Tray Load Depth Sd = Sum of Cable Diameters A = Sum of Cable Areas S/C = Single Conductor M/C = Multiconductor Cables RS = Ladder Rung Spacing
Cooper B-Line, Inc
|
| Yes |
| S/C |
| ||
|
|
|
| ||||
392.10(A)(2) |
| 250 |
| ||||
W ≥ A/1.1 |
|
|
|
| kcmil up to |
| |
|
|
|
|
| |||
|
|
| 1000 |
| |||
|
|
|
|
| |||
|
|
|
|
| kcmil |
| |
|
|
|
|
|
| ||
|
|
|
|
|
| No |
|
|
|
|
|
|
|
| |
392.10(A)(3) |
|
|
|
|
| Note: Use when mixing | |
Yes |
| S/C | |||||
|
|
| 250 kcmil | 250 thru 1000 kcmil | |||
|
|
|
|
| |||
W ≥ A/1.1 +Sd |
|
|
| and | cables with cables larger | ||
|
|
|
|
| larger | than 1000 kcmil. | |
No
392.10(A)(4) | Yes | S/C 1/0 | |
W ≥ Sd |
|
| |
|
| thru 4/0 | |
(9” max. RS) |
|
| |
|
|
| |
|
|
|
|
Appendix Sheet 8
Cable Tray Manual
52