In an electrical installation or an electricity supply system and an earthing system or grounding
system connects specific parts of that installation with the Earth's conductive surface for safety
and functional purposes.
In other words, to connect the metallic parts of electric machinery and devices to the earth
plate or earth electrode through a thick conductor wire for safety purpose is known as Earthing
or grounding.
In this video we will go to give you a brief overview of different types of grounding systems
and Methods of Earthing.
I hope it can help to understand about earthing system.
TT Earthing system:
This system normally used for consumer power supply.
No earthing system provided by power distributor.
The owner must install the earthing protection by their own connection to the earth.
They must installing a suitable electrode and safe arrangement for which they are responsibility
to their installation.
IT Earthing System:
This system is similar with TT system but totally different in earthing supply.
The distributor system not have any connections to earth or it have only a high impedance
connection.
It mean the usual protection is not effective for this system.
This type is not for consumer power supply, special for power distributor such as substation
or generator area.
TN-S Earthing System:
This system has the neutral of power supply with connection of earth only at one point
to the source.
The consumer’s earthing terminal is usually connected to the metallic Armour of the distributor’s
cable into the High voltage and low Voltage transformer.
TN-C-S Earthing System:
This system has the supply neutral conductor of a distribution main connected with earth
at source as protective multiple earthing.
The supply distributor neutral conductor is also used to return earth fault currents from
the consumer installation back to the source with a safely manner.
The power supply distributor will provide a consumer’s earthing terminal which is
linked to the incoming neutral conductor.
This combined earth and neutral system called the protective and neutral conductor or the
combined neutral and earth conductor.
TN-C Earthing system:
This system is not familiar or unusual for earthing system.
It a combined neutral conductor fulfills the functions of both a PE and an N conductor.
The neutral conductor is the sheath of a cable and therefore is concentric with (totally
surrounds) the phase conductor.
Now we will brief Methods of Earthing.
Earthing can be done in many ways.
The various methods employed in earthing Such as, House wiring or factory and other connected
electrical equipment and machines are discussed as follows.
Plate Earthing:
In plate earthing system, a plate made up of either copper with dimensions 60cm * 60cm
* 3.18mm or galvanized iron of dimensions 60cm * 60cm * 6.35 mm is buried vertical in
the earth pit, which should not be less than 3 meter from the ground level.
Pipe Earthing:
A galvanized steel and a perforated pipe of approved length and diameter is placed vertically
in a wet soil in this kind of system of earthing.
It is the most common system of earthing.
Strip or Wire Earthing:
In this method of earthing, strip electrodes of cross-section not less than 25mm * 1.6mm
is buried in a horizontal trenches of a minimum depth of 0.5meter.
If copper with a cross-section of 25mm * 4mm is used and a dimension of 3.0mm. if it’s
a galvanized iron or steel.
Dear sir, Thanks for watching the video.
For more update please subscribes our channel Learning Engineering, and to get notification
press the bell icon.