Presentation on theme: "ASSIGNMENT TEACHER Smt. K.VASUMATHY GROUP MEMBERS:- MANSI DWIVEDI (ET 4 TH SEM) ARTI DWIVEDI (ET 4 TH SEM) DIKSHA CHANDRAKAR (ET 4 TH SEM) MAMTA CHOUDHARY."— Presentation transcript:
ASSIGNMENT TEACHER Smt. K.VASUMATHY GROUP MEMBERS:- MANSI DWIVEDI (ET 4 TH SEM) ARTI DWIVEDI (ET 4 TH SEM) DIKSHA CHANDRAKAR (ET 4 TH SEM) MAMTA CHOUDHARY (ET 4 TH SEM) ANURABH KAR (ET 4 TH SEM)
TELECOM EARTHING TOPICS # INTRODUCTION # CLASSES & PRINCIPLE OF TELECOM EARTHING # PURPOSE & REQUIREMENTS OF TELECOM EARTHING # EARTH ELECTRODE & ITS TYPES # COMPONENTS OF EARTHING # LIMITATIONS OF TELECOM EARTHING
# Earthing is a necessary measure of protection from hazardous electric currents which may result either due to power induction, lighting or short circuits. # The electric charges could be reduced by connecting charged body to the earth through an electrode. # earthing is used for protection at every point of supply network from generator to the electrical apparatus using by the consumer.
It is classified into two system :- # Service Earthing systems # Protective Earthing systems
# Satisfied current carrying capability(AC or DC). # Satisfied mechanical strength to continue the service without fracturing. # Satisfied sudden powerful current carrying ability in case of lightning.
PURPOSE of Earthing # To reduce external interference of noise. # To protect buildings & other equipments from lightning strikes. # To protect persons from leakage of currents. # It helps us to provide stability of voltage conditions in excess fluctuations.
# Service-Earthing system should have low D.C. resistance in order to ensure that the potential drop across the earth connection should be low. # If current flows through through the station a potential difference is developed across the earth station. # This introduces an electrical noise in the circuit. # The value of resistance depend upon the purpose for which the earth is likely to be carried by the station. # Administrator usually uses resisitance not more than 10 ohms.
REQUIREMENTS for PROTECTIVE EARTHING SYSTEM # Earth, which protect against excessive current must have low resistance in order to carry the over current without overheating & burning. # It should able to withstand in corrosive action of soil. # Enable sufficent current to flow through the ground so current protective devices will operate to disconnect the current after a very short time.
ADVANTAGES OF TELECOM EARTHING # Earthing prevents from lightning & short circuits. # Earthing protects consumers at every point of supply network from generator to electrical apparatus. # i t conducts both AC & DC currents.
WHAT IS GROUNDING? “ A Conducting connection whether intentional or not, between electric circuits or equipments & the Earth or some conducting body that serves in place of Earth.”
Important points for grounding Important points are:- * Ground resistance should be below 1 ohm. * A Star confugration should be implemented. * Ground loops should be avoid. * There should be potential equalization.
WHAT IS EARTH ELECTRODE ? # A Metal plate,Water pipe or other conductor of electricity partially buried in the earth so as to constitute & provide a reliable conducting path to the ground. They are of 4 types:- # ROD Electrode # PLATE electrode # STRIP electrode # RING electrode
Limitations of earthing # Chemical treatment of Earth using salts etc. are not recommended. # Earthing conductors should not pass through any metallic conduct or pipe. # All the joints of the similar metals should be water proof. # There should be no sharp bends along the entire length of the earth conductors.