PPT on earthing, grounding and isolation made by the students of SVIT,Vasad under the valuable guidance of the faculties teaching us Electronics and Electrical workshop(EEW) under the course of GTU.

1. Electrical and electronics
workshop
PPT on Earthing, grounding and
isolation
Under the valuable guidance of
Ms.Ami Patel
Made by
Aarsh Shukla {17BECEN022, Enr 115}
Dhananjaysinh Jhala{17BECEM041, Enr 27}
Sarveshkumar Purohit {17BECEG033, Enr 91 }

2. CONTENTS
 What is earthing ?
 Purpose of earthing
 Methods of earthing
 Grounding
 Difference between earthing & grounding
 Types of grounding
 Isolation

3. WHAT IS EARTHING ?
 Earthing means the connection of the neutral
point of a supply system to the earth by a
wire of negligible resistance so in case of
immediate discharge of electrical energy,
there is no damage,
 This brings the body of equipment to zero
potential and electric shock to operator is
avoided.

4. PURPOSE OF EARTHING
 The basic purpose of earthing is to achieve
the following objectives:
 To save human life from danger/shock/death by
blowing fuse of leaky apparatus
 To protect all machines fed from overhead lines
from lightning
 to protect large buildings from atmospheric
lightning
 To maintain the line voltage constant

6. METHODS OF EARTHING
 Strip earthing: strips/wires are buried in
horizontal trenches
 Earthing through water mains: a stranded
copper lead is rounded on a pipe using steel
binding
 Rod earthing: a copper rod is hammered
directly in the earth
 Pipe earthing
 Plate earthing

8. GROUNDING
 Grounding is done for safety of the power
system equipment by connecting the live
parts of it to the earth for providing a return
path to the current in case of faulty/abnormal
conditions like transients, lightening etc.
 Return path is the path that the current
traces to go back to the source, i.e. the
current flows in loops. This path is generally
of a low impedance value.

9. EARTHING VS GROUNDING
EARTHING GROUNDING
Earthing means connecting the dead
part(the one which does not carry
current under normal condition) to the
earth(ground).
Grounding means connecting the live
part(the one which carry current under
normal condition) to the earth (ground) .
Earthing is to ensure safety or protection
of electrical equipment and living being
by discharging electrical energy to earth
(ground).
Grounding provides a safe return path
around the electrical system of your
house thus minimizing damage from
occurrences like lightning...
For example electrical equipment frames
etc.
For example grounding of neutral point
of a star connected transformer.
Finally There is no major difference between earthing and
Grounding, both means “Connecting an electrical circuit or
device to the Earth”

10. TYPES OF GROUNDING
 They are 2 types of grounding: multi point,
single point and mixed grounding.
 Multi point grounding:
 the multi-point system does not trace a singular
path back to building.
 Many existing buildings use multi-point
grounding by bonding the same pieces of
electrical equipment to ground bars, building
steel, cold water pipes or other electrodes.

11.  Single point grounding
 Here the entire grounding network is taken back
to building grounding at a common point.
 The main electrical ground bar (MEGB) is used
as the hub of the grounding network to the
building.

12. ISOLATION
 Electrical isolation is required to prevent
damage to either electrical circuit when one of
them is under fault conditions.
 It is also done to isolate high voltage and low
voltage circuits.
 Largely isolation will prevent shock hazards.
With no common reference and each device
floating you cannot build up a harmful voltage
difference between two independent systems to
get a shock.

13. Isolation in Optocoupler[used in remotes]

14.  Isolation is very important in medical
instruments {like ECG machines} where you
have electrodes attached to you and the
machine. You don't want stray currents to
flow from one electrode to another and to
another ground point in the room where you
might touch and get stray currents directed
through your body.