In this file, Cover is many topic like be:
1.What is Earthing?
2.Purpose of Earthing
3.Qualities of Good Earthing
4.Importance of Earthing
5.Type of Earthing
6.Methods of Electrical Earthing
7.General Method of Electrical Earthing Installation
8.How to work Earthing system?
9.Factors Affect to The Earth Impedance
10.Soil Resistivity
11.Applications of Earthing
12.Case Study
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Building Systems Earthing
1. BUILDING SYSTEMS, SAFETY & SERVICES
(2CLDE13)
Name of the topic :- Earthing system in building services
Submitted by:- 1. (18bcl039) Jeel Patel
2. (18bcl043) Naisha Kolcha
Submitted to :- 1. Prof. Tejas Joshi
2. Prof. Hasan Rangwala
2. What Is Earthing??????
Earthing is used to protect us from an electrical shock.
It does this by providing a path for a fault current to flow to earth.
It also cause the protective devices to switch off the electric current to the circuit
that has the fault by help of fuse.
It is the process of transferring the immediate discharge of electricity directly to the
earth plate, by means of low resistance electrical cables or wires.
3.
4. PURPOSE OF EARTHING
To save human life from danger of electrical shock or death by blowing a fuse.
To protect buildings , machinery and appliances under fault conditions i.e. To
ensure that all exposed conductive parts do not reach a dangerous potential.
To provide safe path to dissipate lightning and short circuit currents.
To maintain the voltage at any part of an electrical systems.
5. QUALITIES OF GOOD EARTHING
Must be of low electrical resistance
Must be of good corrosion resistance
Must be able to dissipate high fault current repeatedly
6. IMPORTANCE OF EARTHING
The earthing protects the person from the short-circuit current.
The earthing provides the easiest path to the flow of short circuit current even after
the failure of the insulation.
The earthing protects the apparatus and person from the high voltage surges and
lightning discharge.
7. TYPES OF EARTHING
1. Neutral Earthing
In neutral earthing, the neutral of the system is directly connected to earth by the help
of the GI wire. The neutral earthing is also called the system earthing. Such type of
earthing is mostly provided to the system which has star winding. For example, the
neutral earthing is provided in the generator, transformer, motor etc.
8. 2. Equipment Earthing
Such type of earthing is provided to the electrical equipment. The non-current carrying
part of the equipment like their metallic frame is connected to the earth by the help of
the conducting wire. If any fault occurs in the apparatus, the short-circuit current to
pass the earth by the help of wire. Thus, protect the system from damage.
14. GENERAL METHOD OF ELECTRICAL EARTHING
INSTALLATION
First of all, dig a 5x5ft (1.5x1.5m) pit about 20-30ft (6-9m) in the ground.
Bury an appropriate (usually 600x600x300mm copper plate)
Tight earth lead through nut bolts from two different places on earth plate.
Use two earth leads with each earth plate and tight them.
To protect the joints from corrosion, put grease around it.
Collect all the wires in a metallic pipe from the earth electrode. Make sure
the pipe is 1ft above the surface of the ground.
To maintain the moisture condition around the earth plate.
Use thimble and nut bolts to connect tightly wires to the bed plates of
machines.
Earth continuity conductor which is connected to the body and metallic
parts of all installation should be tightly connected to earth lead.
Test the overall earthing system through earth tester.
15.
16. FACTORS AFFECT TO THE EARTH
IMPEDANCE
Soil
Weather
Electrode type
Electrode size
Near by utilities
Distance between electrode
17. SOIL RESISTIVITY
The resistivity of earth may vary over extremely wide limits, depending on the
composition of the soil and the moisture content
Factors that affect resistivity
- Types of earth
- Layers of different types of soil
- Moisture content
- Temperature
- Chemical composition and concentration of dissolved salt
18. APPLICATIONS OF EARTHING
Protect human against lightning and earth fault condition
Protect the premises against lightning and earth fault condition
Provide low resistance and safe path for lightning and fault current
All metallic enclosure and extraneous conductive parts are at equipotential
LV system earth