Module Five - Cable Tray - NCCER Substation Slides

Module Five - Cable Tray - NCCER Substation Slides

1. Cable Tray Module Five – 26207 -11

2. Upon completion of this module, you will be able to do the following: 1. Describe the components that make up a cable tray assembly. Explain the methods used to hang and secure cable tray. Describe how cable enters and exits cable tray. Select the proper cable tray fitting for the situation. Explain the National Electrical Code ® ( NEC ® ) requirements for cable tray installations. Select the required fittings to ensure equipment grounding continuity in cable. Interpret electrical working drawings showing cable tray fittings. Size cable tray for the number and type of conductors contained in the system. Objectives

3. Under supervision of the instructor, you should be able to: 1. Generate a list of materials for a cable tray layout. List all the components required, including the fasteners required to complete the system. 2. Join two straight, ladder-type cable tray sections together. Performance Tasks

4. Figure 1 – Typical cable tray system

5. Figure 2 – Cross section of cable tray comparing usable dimensions to overall dimensions

6. Figure 3 – Cables rest on the bottom of the tray and are held in place by the longitudinal side rails

7. Figure 4 – Two applications of cable tray channel

8. Figure 5 – Cables packed closely together can impair efficiency

9. Figure 6 – Each tray support should be capable of safely supporting 1.25 times the weight of the entire tray and cable assembly span

10. Figure 7 – Bending of loaded tray

11. Figure 8 – Load of cable creates bending moments along the span

12. Figure 10 – Several ways in which cables may exit from a cable tray

13. Figure 11 – A dropout plate provides a curved surface for the cable to follow as it leaves the tray

14. Figure 13 – Fabricating a cable tray offset with swivel plates

15. Figure 14 – Expansion joint and splice plates

16. Figure 16 – Alternate ways to hang cable tray

17. Figure 17 – Center rail cable tray

18. Figure 18 – NEC ® regulations governing the use of cable tray

19. Figure 19 – NEC ® regulations governing cable tray construction and installation

20. Figure 20 – NEC ® regulations governing cable tray grounding

21. Figure 21 – Sample floor plan of a cable tray system

22. Supplemental Art

23. Course Map

24. Figure 9 – Cable pulley used to facilitate a cable pull in a tray

25. Figure 12 – Typical application of supports in a vertical run

26. Figure 15 – Channel support

27. Appendix

28. Cable Tray Installations

29. Special-Application Cable Management Systems

30. Ladder Tray

31. Basket Tray (1 of 3)

32. Basket Tray (2 of 3)

33. Basket Tray (3 of 3)

34. Center Hung Tray

35. Cable Tray in Raised-Floor Systems

36. Low-Voltage Cable (1 of 2)

37. Low –Voltage Cable (2 of 2)

38. What’s Wrong With This Picture?