|
| COST - Cable Tray vs. Conduit |
| ||
|
| (Equivalent Conductor Fill Areas) |
|
| |
| 16000 | Material Cost |
|
| |
|
|
|
| ||
| 14000 | Labor Cost @ |
|
| |
|
| $25/hr per NECA |
|
| |
| 12000 | labor units. |
|
| |
|
|
|
|
| |
Total | 10000 |
|
|
|
|
|
|
|
|
| |
Installed | 8000 |
|
|
|
|
Cost ($) |
|
|
|
| |
|
|
|
|
| |
| 6000 |
|
|
|
|
| 4000 |
|
|
|
|
| 2000 |
|
|
|
|
| 0 | Ladder | Solid Bottom | EMT | Rigid Steel |
|
| ||||
|
| Cable Tray | Cable Tray | 3 | Conduit |
|
| 1 | 2 | 4 | |
Installation: 200 linear feet of cable supported with four 90° direction changes and all trapeze supports on 8 ft. spans.
1.Hot dip galvanized steel, 18" wide, ladder cable tray (9" rung spacing) with all hardware.
2.Hot dip galvanized steel, 18" wide, solid bottom cable tray and all hardware.
3.7 parallel runs of 3" diameter EMT with concentric bends.
4.7 parallel runs of 3" diameter galvanized conduit with concentric bends.
Note: Above costs are historical figures and do not include cable and cable pulling costs. Cable costs differ per installation and cable/conductor pulling costs have been shown to be considerably less for cable tray than for conduit.
signal circuits, logic input/output (I/O) circuits, etc. There are other cable tray installations which require a higher cost cable than the equivalent conduit installation. Such installations are limited to areas where low smoke emission and/or low flame spread ITC or PLTC cables must be used.
•Conduit banks often require more frequent and higher strength supports than cable trays. 3 inch and larger rigid metal conduits are the only sizes allowed to be supported on 20 foot spans [National Electrical Code® (NEC®) Table 344.30(B)(2)].
•When a cable tray width is increased 6 inches, the cable tray cost increase is less than 10 percent. This substantially increases the cable tray’s wiring capacity for a minimal additional cost. To obtain such an increase in capacity for a conduit wiring system would be very costly.
Cooper
INSTALLATION COST AND
TIME SAVINGS
•Depending on the complexity and magnitude of the wiring system, the total cost savings for the initial installation (labor, equipment and material) may be up to 60 percent for a cable tray wiring system over a conduit wiring system. When there are banks of conduit to be installed that are more than 100 feet long and consist of four or more 2 inch conduits or 12 or more smaller conduits, the labor cost savings obtained using cable tray wiring systems are very significant.
•Many more individual components are involved in the installation of a conduit system and its conductors compared to the installation of a cable tray system and its cables. This results in the handling and installing of large amounts of conduit items vs. small amounts of cable tray items for the same wiring capacity.
Cable Tray Manual
6
