earthing and grounding

SOLANKI

KAUSHAL

CHAVDAMOHIT

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

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

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

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

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

Circuits Service Entrance Panel Metal Water Pipe Metal Gas pipe

Materials in Grounding System

•Must be approved by NEC

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

Check with local building code

Use of Bonding Jumper

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

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

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

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

feet Buried at least 2 ½”

Typically made of metal rods, pipes, or plates

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

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

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

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

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’

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

THANK YOU