392.9.Number of Multiconductor Cables, Rated 2000 Volts, Nominal, or Less, in Cable Trays. (C) Solid Bottom Cable Trays Containing Any Mixture. (2) Cables Smaller Than 4/0
The procedure used in selecting a cable tray width for the type of cable covered in this section is similar to that shown on Appendix Sheet 4 page 48. The maximum allowable cable fill area is in Column 3 of Table 392.9.
392.9.Number of Multiconductor Cables, Rated 2000 Volts, Nominal, or Less, in Cable Trays. (C) Solid Bottom Cable Trays Containing any Mixture. (3) 4/0 or Larger Cables Installed With Cables Smaller Than 4/0
No. 4/0 and larger cables must have a dedicated zone in the tray in order to be installed in one layer. Therefore the cable tray needs to be divided into two zones (a barrier or divider is not required but one can be used if desired).
The formula for this type of installation is shown in Column 4 of Table 392.9. This formula is a trial and error method of selecting a cable tray of the proper width. A direct method for determining the cable tray width is available by figuring the cable tray widths that are required for each of the cable combinations and then adding these widths together to select the proper cable tray width. [Sd (sum of the diameters of the No. 4/0 and larger cables) x (1.11)] + [(Sum of Total
392.9.Number of Multiconductor Cables, Rated 2000 Volts, Nominal, or Less, in Cable Trays. (D) Solid Bottom Cable Tray Multiconductor Control and/or Signal Cables Only.
This is the same procedure as for ladder and ventilated trough cable trays except that the allowable fill has been reduced from 50 percent to 40 percent. The procedure used in selecting a cable
Cooper B-Line, Inc
tray width for the type of cable covered in this section is similar to that shown on Appendix Sheet 6 page 50.
392.9.Number of Multiconductor Cables, Rated 2000 Volts, Nominal, or Less in Cable Trays. (E) Ventilated Channel Cable Trays.
392.9(E)(1)
Where only one multiconductor cable is installed in a ventilated channel cable tray.
Ventilated Channel | Maximum |
Cable Tray Size | Area of the Cable |
|
|
|
|
3 Inch Wide | 2.3 Square Inches |
4 Inch Wide | 4.5 Square Inches |
6 Inch Wide | 7.0 Square Inches |
|
|
392.9(E)(2)
The fill areas for combinations of multiconductor cables of any type installed in ventilated channel cable tray.
Ventilated Channel | Maximum Allowable |
Cable Tray Size | Fill Area |
|
|
|
|
3 Inch Wide | 1.3 Square Inches |
4 Inch Wide | 2.5 Square Inches |
6 Inch Wide | 3.8 Square Inches |
|
|
392.9.Number of Multiconductor Cables, Rated 2000 Volts, Nominal, or Less in Cable Trays. (F) Solid Channel Cable Trays.
392.9(F)(1)
Where only one multiconductor cable is installed in a solid channel cable tray.
Solid Channel | Maximum |
Cable Tray Size | Area of the Cable |
|
|
|
|
2 Inch Wide | 1.3 Square Inches |
3 Inch Wide | 2.0 Square Inches |
4 Inch Wide | 3.7 Square Inches |
6 Inch Wide | 5.5 Square Inches |
|
|
| Cable Tray Manual |
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