EARTHING & GROUNDING

1. EARTHING & GROUNDING • Presentation by -S.Dhanushskanda(13ISCE07) -Nikhil Rana(13BECEG113) -Sumit Chakraborty(13ISCE11) • Branch:C.E(f.y) • Batch:C • Guided By:Sagar Ahire

2. What Earthing Does

3. A Maintenance Free Eathing System

4. Purpose of the Grounding System • Fundamental to the safety of those installing, using, and servicing the electrical system • Assures the system will work properly while preventing damage to the system

5. NEC Requirements • All electrical systems serving structure must be bonded together • Including the following • Electrical wiring system • Telephone system • Phone system • Burgular alarm system • Cable or satellite system

6. Grounding

7. Grounding Bodywork

8. Grounded • Describes the act of being connected to the earth or some other conduction body that serves in place of the earth

9. Bonding

10. Bonding • Reduces the differences in potential between each electrical system • May be caused by power surges, lightning strikes or other types of ground fault type occurences

11. Parts of the Electrical System • Circuits • Service Entrance Panel • Metal Water Pipe • Metal Gas pipe

12. Materials in Grounding System

13. The Grounding Electrode System • All materials must be grounded using approved bonding and grounding electrode systems • Check with local building code

14. Metallic Pipe • Water pipe must always be bonded to the service entrance panel, grounding electrode conductor, or grounding electrode • Other metal pipe, such as gas pipe, which may become energized accidentally must be bonded to the electrical system grounded system

15. Use of Bonding Jumper

16. Metal Underground Water Pipe • Must be bonded to the supplemental grounding system electrode and to the neutral bus bar in the SEP • Connection must be made within 5 feet of entering structure • Water pipe must be in direct contact with the earth for at least 10 feet

17. Concrete Encased Electrode • Electrode encased in foundation footing covered with at least 2 inches of concrete • Electrodes must be at least 20 feet in length and consist of one or more ½” steel reinforcement bars

18. Ground Ring • Bare Copper • At Least #2 AWG or larger • Encircling residence for a length of 20 feet • Buried at least 2 ½”

19. Supplemental Electrodes • Typically made of metal rods, pipes, or plates

20. Rod and Pipe Electrodes • Iron or steel rod electrodes • Must be 5/8” in diameter • Pipe must be ¾” in diameter • Galvanized or metal coated for corrosion resistance • 8 feet in length • Installed to a depth of 8” in direct contact with earth

21. Nonferrous rods must be listed at no less than ½” • Stainless Steel- ½” diamter • Must be at or below ground level • Must be protected from physical damage

22. Exceptions • If electrode can not be driven more than 4” into the earth b/c of rock or other obstruction • May be driven at an oblique and of no more than 45° from vertical • At least 8” of the electrode must be in contact with earth

23. Multiple grounding rods • When more than one electrode grounding rod is used: • Must be installed not less than 6 feet apart • Must be bonded together with an approved bonding jumper to form single grounding electrode system

24. Plate Electrode • May be used in areas where it is not possible to use a grounding rod or ring • Steel/Iron Plate electrode must be ¼” thick • Non-ferrous metal plate must be 0.06” thick • 2 feet square • Buried at least 2 1/2’

25. Grounding Electrode Conductor • NEC permits • Copper • Aluminium • Copper-clad AL and AL-CU may not be used in contact with masonry, corrosive, or in direct contact with the earth

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