CABLE TRAY SIZING FLOWCHART
Start
Sizing Cable Tray Per NEC 392
Here
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| 392.12 |
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| W ≥ Sd |
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| or less |
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| (single layer) |
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| cables |
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| Yes |
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Solid | No | Vented |
| No |
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| Ladder | Yes |
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| No |
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| Yes | ||||||||||
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| S/C 1/0 |
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| Multi- | ||||||||||||||||||||||
Bottom |
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| Channel |
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| or Vented |
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| conductor |
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| Trough |
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| or larger |
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Tray |
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| Tray |
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| cables |
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| Tray |
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| Continued | |||
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| Yes |
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| Yes |
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| Yes |
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| on | next | ||||
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| page | ||||||||
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| S/C |
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392.10 |
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| Yes |
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| 392.3(B)(1)(a) |
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| 392.10(B) |
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| 392.10(A)(1) |
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Not |
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| 1000 |
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| Not permitted |
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recognized by |
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| W ≥ Sd |
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| W ≥ Sd |
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| kcmil or |
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| by the NEC | ® |
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the NEC® |
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| larger |
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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
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| Yes |
| S/C |
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392.10(A)(2) |
| 250 |
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W ≥ A/1.1 |
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| kcmil up to |
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| 1000 |
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| kcmil |
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| No |
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392.10(A)(3) |
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| Note: Use when mixing | |
Yes |
| S/C | |||||
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| 250 kcmil | 250 thru 1000 kcmil | |||
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W ≥ A/1.1 +Sd |
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| and | cables with cables larger | ||
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| larger | than 1000 kcmil. | |
No
392.10(A)(4) | Yes | S/C 1/0 | |
W ≥ Sd |
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| thru 4/0 | |
(9” max. RS) |
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Appendix Sheet 8
Cable Tray Manual
52
