earthing and grounding

22
SOLANKI KAUSHAL CHAVDA MOHIT

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Earthing and Grounding Basics

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Page 1: Earthing and Grounding

SOLANKI

KAUSHAL

CHAVDAMOHIT

Page 2: Earthing and Grounding
Page 3: Earthing and Grounding

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

Page 4: Earthing and Grounding

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

Page 5: Earthing and Grounding

GroundingThe process of making a planned, continuous,

connection between NON-CURRENT CARRYING parts of the electrical wiring installation and the earth and some other conducting body

Page 6: Earthing and Grounding

Process in which all NON-CURRENT CARRYING METALLIC parts of the electrical wiring system are permanently joined together to form a CONTINUOUS grounding path

Page 7: Earthing and Grounding

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

Page 8: Earthing and Grounding

Circuits Service Entrance Panel Metal Water Pipe Metal Gas pipe

Page 9: Earthing and Grounding

Materials in Grounding System

•Must be approved by NEC

Page 10: Earthing and Grounding

All materials must be grounded using approved bonding and grounding electrode systems

Check with local building code

Page 11: Earthing and Grounding

Use of Bonding Jumper

• To provide CONTINUOUS grounding path around devices such as water meters installed in metallic water pipe system

Page 12: Earthing and Grounding

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

Page 13: Earthing and Grounding

Concrete Encased ElectrodeElectrode 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

Page 14: Earthing and Grounding

Bare Copper At Least #2 AWG or larger Encircling residence for a length of 20

feet Buried at least 2 ½”

Page 15: Earthing and Grounding

Typically made of metal rods, pipes, or plates

Page 16: Earthing and Grounding

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

Page 17: Earthing and Grounding

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

Page 18: Earthing and Grounding

ExceptionsExceptions

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

Page 19: Earthing and Grounding

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

Page 20: Earthing and Grounding

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’

Page 21: Earthing and Grounding

Grounding Electrode Conductor NEC permits

Copper Aluminium Copper-cladAL and AL-CU may not be used in contact

with masonry, corrosive, or in direct contact with the earth

Page 22: Earthing and Grounding

THANK YOU