Module Nine - Grounding Systems - NCCER Substation Slides

Module Nine - Grounding Systems - NCCER Substation Slides

1. Grounding Systems Module Nine – 82203-12

2. Objectives Upon completion of this module, you will be able to do the following : Explain the purpose of a ground grid system. Describe the methods and materials for installing an underground grid. Explain the safety precautions used and the PPE required when repairing and/or expanding an existing ground grid. Describe how connections are made in a ground grid system using exothermic welded, compression, and mechanical connectors.

3. Performance Tasks Under the supervision of the instructor, you should be able to do the following : Make connections in a ground grid system using exothermic welded, compression, and mechanical connectors.

4. Figure 1 — Substation

5. Figure 2 — Electrostatic induction

6. Figure 3 — Electromagnetic induction

7. Figure 4 — Energized soil around an energized grounded object

8. Figure 5 — Step potential hazard

9. Figure 6 — Touch potential hazard

10. Figure 7 — Connections to a grounded grid

11. Figure 8 — Substation grounding plan

12. Figure 9 — Wenner four-point method

13. Figure 10 — Electrolytic electrode

14. Figure 11 — Ground grid layout

15. Table 1 — Ground Grid Conductor Sizes

16. Figure 12 — Fence ground grid dimensions

17. Figure 13 — Ground grid connections

18. Table 2 — Connection Method Advantages and Disadvantages

19. Figure 14 — Mechanical connector

20. Figure 15 — Cable-to-cable mechanical connectors

21. Figure 16 — Mechanical ground connection assembly

22. Figure 17 — Compression connector

23. Figure 18 — Types of compression connectors

24. Figure 19 — Die number stamped in connector body

25. Figure 20 — Crimping tool

26. Figure 21 — Exothermic weld mold

27. Figure 22 — Exothermic electronic igniter

28. Figure 23 — Completed exothermic weld

29. Figure 24 — Cable-to-cable mold configurations

30. Figure 25 — Exothermic welding steps

31. Figure 26 — Ground rod placement

32. Figure 27 — Ground rod installation

33. Figure 28 — Equipotential zone below switch handle

34. Figure 29 — Fall-of-potential test setup

35. Figure 30 — Ground grid test report form

36. Figure 31 — Temporary ground mat

37. Supplemental Art

38. Course Map