The document discusses electrical safety and earthing systems. It notes that over 2000 deaths occur every year in India due to electrical faults. Proper earthing can prevent over 95% of electrical accidents. Earthing systems work by connecting exposed metal parts of electrical systems to the earth, providing an alternative path for faults and preventing dangerous voltages. Common earthing methods include plate, pipe, rod and strip earthing, which involve burying conductive plates, pipes or rods underground to dissipate electricity into the earth. Proper earthing is crucial for safety and protection of buildings, equipment and human life.

1. BY RA KIRUTHIKA
III B.Sc PHYSICS C
12.07.2021

2. NATIONAL CRIME RECORDS BUREAU REPORTS
 2000+ death every year in fire due to
electrical fault
 10000+ death due to electrocution
 Plus many more unreported cases
 Loss of crores of rupees due to damage to
property
Can we stop
this ?
Types
of
Earthi
ng
2
21-01-
2019

3. CAUSED OF ELECTRICAL
ACCIDENTS
Reason
Faulty and fried wiring
Too many equipment in Extension
cords
Faulty electrical appliances
Outdated circuit breakers
Light fixtures and decorations
Electrical switches and outlets
Unattended charging points
 Insulation
failure
 Over current
 Heat and fire
 Electrocution
Definitions
2
3

4. PROTECTION
21-01-
2019
Department of Electrical Engineering, College of Engineering
Trivandrum
 Fire prevention
 Smoke / Fire detection
 Fire Suppression
 Smoke / Fire sealing
 Evacuation
 Rules and regulations
 More than 95% of the accidents
can be avoided if the supply is
disconnected within the stipulated
time
Basic
Protection
 Insulation of Live
Parts
 Barriers or
Enclosure
Fault Protection
Automatic
Disconnection of supply
Double insulation
Separation
ELV System for
Buildings
(Extra Low Voltage)
Protection
Devices
2
4
21-01-
2019
Department of Electrical Engineering, College of
Engineering Trivandrum

5. Concept of Earthing Systems
What Is Earthing ?
Purpose of Earthing
Methods of Earthing

6. Concept of Earthing Systems
All the people living or working in residential,
commercial and industrial installations, particularly
the operators and personnel who are in close
operation and contact with electrical systems and
machineries, should essentially be protected against
possible electrification. To achieve this protection,
earthing system of an installation is defined,
designed and installed according to the standard
requirements..

7. WHAT IS EARTHING
The process of connecting metallic bodies of all
the electrical apparatus and equipment to huge
mass of earth by a wire having negligible
resistance is called Earthing.

8. • To save human life from danger of electrical shock or death by
blowing a fuse i.e. To provide an alternative path for the fault
current to flow so that it will not endanger the user
• To protect buildings, machinery & appliances under fault
conditions ie. 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 provide stable platform for operation of sensitive electronic
equipments i.e. To maintain the voltage at any part of an
electrical system at a known value so as to prevent over current
or excessive voltage on the appliances or equipment .
• To provide protection against static electricity from friction

9.  When a high voltage such as 13,800V is involved the body is
literally cooked and at times explodes
Electric shock

10. Methods of Earthing
Plate Earthing
Pipe Earthing
Rod Earthing
Strip Earthing
Earthing through
Water Mains

11. EARTHING ELECTRODE
The resistance of a ground
electrode has 3 basic
components:
A) The resistance of the ground
electrode itself and the connections
to the electrode.
B) The contact resistance of the
surrounding earth to the electrode.
C) The resistance of the surrounding
body of earth around the ground
Electrode. It consist of three basic components:
1. Earth Wire
2. Connector
3. Electrode

12. PLATE EARTHING
In plate earthing system, a plate made up
of either copper with dimensions 60cm x
60cm x 3.18mm (i.e. 2ft x 2ft x 1/8 in) or
galvanized iron (GI) of dimensions 60cm x
60cm x 6.35 mm (2ft x 2ft x ¼ in) is buried
vertical in the earth (earth pit) which should
not be less than 3m (10ft) from the ground
level.

13.  In this type of earthing plate either of copper or of
G.I. is buried into the ground at a depth of not less
than 3 meter from the ground level.
 The earth plate is embedded in alternative layer of
coke and salts for a minimum thickness of about
15cm.
 The earth wire(copper wire for copper plate
earthing and G.I. wire for G.I. plate earthing) is
securely bolted to an earth plate with the help of
bolt nut and washer made of copper, in case of
copper plate earthing and of G.I. in case of G.I.
plate earthing.

14. PLATE EARTHING