Electricity was first discovered in 600 BC but scientific understanding began in the 18th century. Key discoveries included friction electricity by Thales in 600 BC, the word "electricity" coined in 1600, and the first chemical battery invented by Volta in 1800. Thomas Edison helped bring electricity to homes in New York in 1882, but most homes did not have power until 1925. Edison also invented the incandescent light bulb in 1879. Electricity starts at power plants, is transmitted through high voltage lines and substations, distributed through lower voltage lines, and finally enters homes through service drops. Proper safety precautions must be taken when working with electricity to avoid shock and fire.
This document provides information on fuses and circuit breakers used in electrical systems. It discusses the purpose of fuses and circuit breakers as overcurrent protection devices that open a circuit when too much current flows. The key components and operating principles of fuses and various types of circuit breakers like thermal, magnetic, and thermomagnetic are described. Characteristics such as rated current, breaking capacity, and time-current curves are also covered.
The fuse protects electric circuits from excessive current by containing a wire that melts when overheated. There are two main types: replaceable wire fuses and cartridge fuses. The fuse rating indicates the maximum current it can withstand without melting. Fuses should be rated slightly higher than the appliance's normal current to prevent tripping during regular use. Earth wires connect appliances to ground and provide a path for current in case of a loose live wire, preventing electric shocks.
The document discusses lightning arresters, including their working principle, types, and advantages/disadvantages. Lightning arresters protect electrical equipment by diverting high voltage surges from lightning strikes or nearby objects to ground. They break down at a preset voltage to provide a path of least resistance to ground. Common types include rod gap, sphere gap, horn gap, and metal oxide arresters. Lightning arresters help reduce property damage and protect outdoor substation equipment and power lines from damage from lightning strikes. However, they require more space and have a higher installation cost than some alternatives.
The document discusses different types of earthing systems used in electrical installations. It provides details on:
- The purpose of earthing systems which is to provide protection from electric shocks and maintain safe voltages.
- Common types of earthing methods including plate, pipe, rod and strip earthing. It also discusses maintenance free earthing systems.
- Factors that determine good earthing including low resistance, corrosion resistance and ability to dissipate high fault currents.
- Causes of short circuits and how earthing provides protection during faults.
- Maximum earth resistance values that should be achieved for different electrical equipment.
in this presentation i have completely described the basic constriction and working of Surge Arresters so that you will find it easy to understand and it can be easily delivered to the listeners
The document defines and describes different types of overvoltages that can occur on power systems, including temporary, transient, lightning, and switching overvoltages. It explains that overvoltages are caused by both internal factors like switching and insulation failures, as well as external lightning strikes. The mechanism of lightning is then described in detail, including how charge separation in storm clouds leads to the formation of stepped leaders and streamers, completing an ionized conductive path between the cloud and earth.
study of lightning arrester ' working principal and working of lighning and construction of lightning arrester. and at the end what are the types of lightning arrester how these types are different from each other and what is their working principal and which is used mostly on 500kva substation.
This document provides information on fuses and circuit breakers used in electrical systems. It discusses the purpose of fuses and circuit breakers as overcurrent protection devices that open a circuit when too much current flows. The key components and operating principles of fuses and various types of circuit breakers like thermal, magnetic, and thermomagnetic are described. Characteristics such as rated current, breaking capacity, and time-current curves are also covered.
The fuse protects electric circuits from excessive current by containing a wire that melts when overheated. There are two main types: replaceable wire fuses and cartridge fuses. The fuse rating indicates the maximum current it can withstand without melting. Fuses should be rated slightly higher than the appliance's normal current to prevent tripping during regular use. Earth wires connect appliances to ground and provide a path for current in case of a loose live wire, preventing electric shocks.
The document discusses lightning arresters, including their working principle, types, and advantages/disadvantages. Lightning arresters protect electrical equipment by diverting high voltage surges from lightning strikes or nearby objects to ground. They break down at a preset voltage to provide a path of least resistance to ground. Common types include rod gap, sphere gap, horn gap, and metal oxide arresters. Lightning arresters help reduce property damage and protect outdoor substation equipment and power lines from damage from lightning strikes. However, they require more space and have a higher installation cost than some alternatives.
The document discusses different types of earthing systems used in electrical installations. It provides details on:
- The purpose of earthing systems which is to provide protection from electric shocks and maintain safe voltages.
- Common types of earthing methods including plate, pipe, rod and strip earthing. It also discusses maintenance free earthing systems.
- Factors that determine good earthing including low resistance, corrosion resistance and ability to dissipate high fault currents.
- Causes of short circuits and how earthing provides protection during faults.
- Maximum earth resistance values that should be achieved for different electrical equipment.
in this presentation i have completely described the basic constriction and working of Surge Arresters so that you will find it easy to understand and it can be easily delivered to the listeners
The document defines and describes different types of overvoltages that can occur on power systems, including temporary, transient, lightning, and switching overvoltages. It explains that overvoltages are caused by both internal factors like switching and insulation failures, as well as external lightning strikes. The mechanism of lightning is then described in detail, including how charge separation in storm clouds leads to the formation of stepped leaders and streamers, completing an ionized conductive path between the cloud and earth.
study of lightning arrester ' working principal and working of lighning and construction of lightning arrester. and at the end what are the types of lightning arrester how these types are different from each other and what is their working principal and which is used mostly on 500kva substation.
POWER SYSTEM PROTECTION
Protection Devices and the Lightning,. protection,
Lightning protection, Introduction
Air Break Switches
Disconnect switches
Grounding switches
Current limiting reactors
Grounding transformers
Co-ordination of protective devices
Grounding of electrical installations
Electric shock
Lightning protection
Lightning Arrestor
A lightning arrester, also known as a lightning conductor, is a device used to protect electrical power systems and telecommunications systems from damage caused by lightning strikes. It has a high voltage terminal connected to the power line and a ground terminal. When a lightning surge travels along the power line, the arrester diverts the current through itself to ground, usually by means of an arc across an air gap. Common types of lightning arresters include rod arresters, horn gap arresters, multi gap arresters, and various types using silicon carbide or metal oxide components. A horn gap arrester consists of two horn-shaped metal rods separated by a small air gap, connected to the power line through a resistance and choke coil to
This document discusses electrical safety and provides information on basic electrical principles including electricity, electric current, potential difference, conductors, resistance, and Ohm's law. It also covers safe working practices with electricity such as lock out procedures, personal protective equipment, and portable electrical equipment maintenance. Key risks from electricity like electric shock and electrical fires are explained. The document emphasizes isolating electrical sources, inspecting equipment, and using proper safety procedures to prevent accidents.
This document discusses surge currents in power systems and how superconducting fault current limiters (SFCLs) can help protect against them. It begins with an introduction to modern power system growth and the need to protect against faults. It then defines surge currents and explains superconductors and the Meissner effect. Different types of SFCLs are described, including resistive, shielded core, and magnetic shielding types. Applications and benefits of SFCLs are provided. In conclusion, SFCLs offer efficient advantages for power system protection by utilizing the properties of superconducting materials.
Faraday's law of induction states that (1) a changing magnetic flux induces an electromotive force (EMF) in any closed circuit, and (2) the magnitude of the induced EMF is directly proportional to the rate of change of the magnetic flux through the circuit. The document provides examples of Faraday's law in transformers, induction cookers, and musical instruments. It also discusses the advantages of Faraday's law such as efficiency and its applications. Numerical problems are included to calculate induced EMF and current in a coil.
Electrical safety is an important issue that can prevent fatalities and injuries. Each year, contact with overhead power lines results in deaths and property damage. Working near electricity puts many workers at risk, including equipment operators, emergency responders, and those on ladders or scaffolds. Even small amounts of electricity can cause harm, with just 75mA potentially causing death. Proper safety training and coordinating work with utilities can help prevent electrical accidents.
Surge current protection using superconductor pptChirag2016
This document summarizes a seminar presentation on using superconductors for surge current protection. It introduces surge currents and the need for protection against them. It then discusses superconductors and how they can conduct electricity with zero resistance below a critical temperature. Different types of superconductors are presented, as well as how superconductive surge current limiters work by providing high impedance above a given current threshold. The document concludes by discussing advantages of using superconductors for this application and future plans to introduce them into power grid transmission systems.
This document discusses types of lightning arresters. It begins by explaining what lightning is and the mechanism of lightning discharge. There are two main types of lightning strokes: direct and indirect. Lightning arresters protect equipment by providing a low resistance path for surges to ground. The main types discussed are rod gap, horn gap, multigap, expulsion, and valve arresters. Valve arresters, which incorporate nonlinear resistors and spark gaps, are most effective and commonly used on high voltage systems above 66kV. The document concludes by mentioning IEC surge arrester testing standards.
Superconducting fault current limiters (SFCLs) use the properties of superconductors to limit fault currents on electric distribution and transmission systems. SFCLs maintain near-zero resistance under normal operation but transition to a resistive state during faults to limit excessive currents. Several types have been developed including inductive, resistive, shielded-core, and saturable-core designs. SFCLs allow increased utilization of existing grid equipment and infrastructure by controlling fault currents. They are being pursued by utilities worldwide with commercial devices expected by 2000.
The document discusses superconductors, which are materials that lose all electrical resistance below a critical temperature. It describes how superconductivity was discovered in 1911 by Kammerlingh Onnes. The key properties of superconductors are zero resistance, the Meissner effect of expelling magnetic fields, and ability to levitate objects. There are two types of superconductors based on their critical magnetic field properties. Applications include MRI, maglev trains, and particle accelerators. Advantages are efficient power transmission and small devices, while limitations are the need for extremely low temperatures and brittleness.
Designing and testing of metal oxide surge arrester for EHV lineRohit Khare
Surge arresters constitute an indispensable aid to insulation coordination in electrical power systems. There the voltages which may appear in an electrical power system are given in per-unit of the peak value of the highest continuous line-to-earth voltage, depending on the duration of their appearance. The voltage or overvoltage which can be reached without the use of arresters is a value of several p.u. If instead, one considers the curve of the withstand voltage of equipment insulation (here equipment means electrical devices such as power transformers) one notices that starting in the range of switching overvoltages, and especially for lightning over voltages, the equipment insulation cannot withstand the occurring dielectric stresses. At this point, the arresters intervene. When in operation, it is certain that the voltage that occurs at the terminal of the device - while maintaining an adequate safety margin - will stay below the withstand voltage. Arresters’ effect, therefore, involves lightning and switching over voltages.
The time axis is roughly divided into the range of lightning overvoltage (microseconds), switching overvoltages (milliseconds), temporary overvoltages (seconds) – which are commonly cited by the abbreviation "TOV" – and finally the temporally unlimited highest continuous system operation voltage.
This document summarizes types of lightning arresters, their classification, identification, standard ratings, and service conditions. There are three main types of arresters: expulsion, valve, and gapless metal-oxide. Arresters are classified into four classes based on their nominal discharge current and use: station, intermediate, distribution, and secondary. Arresters must be properly identified and can operate under normal conditions of temperature, radiation, altitude, and frequency, but may require special consideration under abnormal conditions.
Over voltages can be caused by internal factors like switching operations or insulation failures, or external factors like lightning. Lightning arrestors protect equipment by diverting high voltage surges to ground. They break down temporarily during over voltages and regain insulation at normal voltages. Insulation coordination determines equipment insulation strength to withstand normal operating voltages and temporary over voltages based on factors like highest system frequency, temporary over voltages, and transient surges. Equipment is tested and rated with a basic insulation level to ensure it can withstand impulse voltages above that level.
A surge diverter protects electrical equipment from voltage surges by diverting excess voltages caused by spikes in the electrical supply to earth. There are different types of surge diverters, including rod gap, protector tube, and valve type diverters. Rod gap diverters consist of two rods with a gap that sparks over during a surge to discharge current to ground. Protector tube diverters improve on rod gaps by enclosing the gaps to extinguish follow-on arcs. Valve type diverters incorporate non-linear resistors to provide a low resistance path for surges while blocking normal voltages and currents.
Superconductivity is a phenomenon where materials exhibit zero electrical resistance and expel magnetic fields when cooled below a critical temperature. It is characterized by the Meissner effect, where superconductors push out magnetic fields. Superconductors can carry direct electric currents without resistance, allowing the current to flow undiminished forever. The crystal structures of high-temperature superconductors contain copper-oxide layers. Type I superconductors exhibit a sudden transition from the superconducting to normal state at a critical magnetic field, while type II superconductors can be penetrated by magnetic fields and are useful for applications. Superconductors have applications in power transmission, telecommunications, transportation, computing, medical imaging and other areas.
This document discusses using superconductors for surge current protection in power systems. It begins with an introduction to surge currents and superconductors. Superconductors conduct electricity with zero resistance below a critical temperature. There are two main types of superconductors: low-temperature and high-temperature. Fault current limiters (FCLs) use superconductors to limit surge currents during faults. FCLs come in resistive and inductive varieties. FCLs can protect equipment by limiting current flow and extending component lifetimes. Future applications include installing FCLs at transmission voltages of 500kV. Superconducting FCLs offer efficient protection for power systems.
Surge current protection using superconductor ppt maheshKuldeep Singh
This seminar discusses using superconductors for surge current protection. Superconductors conduct electricity with zero resistance below a critical temperature. They can be used as fault current limiters to protect power systems when faults occur. Two main types of superconductor fault current limiters are resistive and inductive. Superconductive fault current limiters offer advantages like safety, reliability, and extended equipment life. Future plans include developing three-phase limiters for testing on power grids this century. Superconductive fault current limiters have applications in transmission and distribution systems.
This document provides guidance on electrical insulation testing. It discusses what constitutes good insulation, how insulation resistance is measured using a Megger insulation tester, and different types of insulation resistance tests including short-time or spot-reading tests and time-resistance tests. Factors that can affect insulation resistance readings, such as temperature, humidity, and the length of time voltage is applied, are also covered.
Surge arrestors are protective devices that limit voltage spikes and surges from damaging electrical equipment. They work by diverting excess current during events like lightning strikes or power faults to ground. When voltage increases, the resistor inside the arrestor decreases in resistance, allowing extra current to drain out and prevent voltage from increasing in protected equipment. Surge arrestors are installed at substations and near transformers to shield sensitive equipment from voltage transients. They parallel arrangement allows surges to be discharged without propagating through the system.
The Different Types of Inductors and Their Affecting Factorselprocus
An inductor is also named as a reactor, coil and choke. It is a two terminal electrical component used in various electrical and electronic circuits. An inductor is used to store energy in the form of a magnetic field. Learn the different types of inductors and their affecting factors and have a wide variety and important applications in electronics.
This document provides an overview of electric power systems, including their history and basic concepts. It discusses how electric power systems evolved from early experiments in the 18th century through the development of generators, transformers, and interconnected grids. The key concepts of voltage, current, power, energy, direct current, alternating current, frequency, and the three types of loads - resistive, inductive, and capacitive - are explained. Today's electric power systems generate power, transmit it over high-voltage lines, transform the voltage, and distribute power to homes and businesses in real-time as it is consumed.
Brief information of Electricity and wiring Mani Das
Electricity is a form of energy involving the flow of electrons. Benjamin Franklin first invented electricity and studied it, while Alessandro Volta discovered that chemical reactions can produce electricity and invented the first battery. Electricity can be generated through various means like heat, falling water, wind, solar, and chemical energy. There are two types of electric current: direct current where electrons flow in one direction and alternating current where electrons repeatedly change direction. Electricity has many applications like powering homes and industry as well as operating machines.
POWER SYSTEM PROTECTION
Protection Devices and the Lightning,. protection,
Lightning protection, Introduction
Air Break Switches
Disconnect switches
Grounding switches
Current limiting reactors
Grounding transformers
Co-ordination of protective devices
Grounding of electrical installations
Electric shock
Lightning protection
Lightning Arrestor
A lightning arrester, also known as a lightning conductor, is a device used to protect electrical power systems and telecommunications systems from damage caused by lightning strikes. It has a high voltage terminal connected to the power line and a ground terminal. When a lightning surge travels along the power line, the arrester diverts the current through itself to ground, usually by means of an arc across an air gap. Common types of lightning arresters include rod arresters, horn gap arresters, multi gap arresters, and various types using silicon carbide or metal oxide components. A horn gap arrester consists of two horn-shaped metal rods separated by a small air gap, connected to the power line through a resistance and choke coil to
This document discusses electrical safety and provides information on basic electrical principles including electricity, electric current, potential difference, conductors, resistance, and Ohm's law. It also covers safe working practices with electricity such as lock out procedures, personal protective equipment, and portable electrical equipment maintenance. Key risks from electricity like electric shock and electrical fires are explained. The document emphasizes isolating electrical sources, inspecting equipment, and using proper safety procedures to prevent accidents.
This document discusses surge currents in power systems and how superconducting fault current limiters (SFCLs) can help protect against them. It begins with an introduction to modern power system growth and the need to protect against faults. It then defines surge currents and explains superconductors and the Meissner effect. Different types of SFCLs are described, including resistive, shielded core, and magnetic shielding types. Applications and benefits of SFCLs are provided. In conclusion, SFCLs offer efficient advantages for power system protection by utilizing the properties of superconducting materials.
Faraday's law of induction states that (1) a changing magnetic flux induces an electromotive force (EMF) in any closed circuit, and (2) the magnitude of the induced EMF is directly proportional to the rate of change of the magnetic flux through the circuit. The document provides examples of Faraday's law in transformers, induction cookers, and musical instruments. It also discusses the advantages of Faraday's law such as efficiency and its applications. Numerical problems are included to calculate induced EMF and current in a coil.
Electrical safety is an important issue that can prevent fatalities and injuries. Each year, contact with overhead power lines results in deaths and property damage. Working near electricity puts many workers at risk, including equipment operators, emergency responders, and those on ladders or scaffolds. Even small amounts of electricity can cause harm, with just 75mA potentially causing death. Proper safety training and coordinating work with utilities can help prevent electrical accidents.
Surge current protection using superconductor pptChirag2016
This document summarizes a seminar presentation on using superconductors for surge current protection. It introduces surge currents and the need for protection against them. It then discusses superconductors and how they can conduct electricity with zero resistance below a critical temperature. Different types of superconductors are presented, as well as how superconductive surge current limiters work by providing high impedance above a given current threshold. The document concludes by discussing advantages of using superconductors for this application and future plans to introduce them into power grid transmission systems.
This document discusses types of lightning arresters. It begins by explaining what lightning is and the mechanism of lightning discharge. There are two main types of lightning strokes: direct and indirect. Lightning arresters protect equipment by providing a low resistance path for surges to ground. The main types discussed are rod gap, horn gap, multigap, expulsion, and valve arresters. Valve arresters, which incorporate nonlinear resistors and spark gaps, are most effective and commonly used on high voltage systems above 66kV. The document concludes by mentioning IEC surge arrester testing standards.
Superconducting fault current limiters (SFCLs) use the properties of superconductors to limit fault currents on electric distribution and transmission systems. SFCLs maintain near-zero resistance under normal operation but transition to a resistive state during faults to limit excessive currents. Several types have been developed including inductive, resistive, shielded-core, and saturable-core designs. SFCLs allow increased utilization of existing grid equipment and infrastructure by controlling fault currents. They are being pursued by utilities worldwide with commercial devices expected by 2000.
The document discusses superconductors, which are materials that lose all electrical resistance below a critical temperature. It describes how superconductivity was discovered in 1911 by Kammerlingh Onnes. The key properties of superconductors are zero resistance, the Meissner effect of expelling magnetic fields, and ability to levitate objects. There are two types of superconductors based on their critical magnetic field properties. Applications include MRI, maglev trains, and particle accelerators. Advantages are efficient power transmission and small devices, while limitations are the need for extremely low temperatures and brittleness.
Designing and testing of metal oxide surge arrester for EHV lineRohit Khare
Surge arresters constitute an indispensable aid to insulation coordination in electrical power systems. There the voltages which may appear in an electrical power system are given in per-unit of the peak value of the highest continuous line-to-earth voltage, depending on the duration of their appearance. The voltage or overvoltage which can be reached without the use of arresters is a value of several p.u. If instead, one considers the curve of the withstand voltage of equipment insulation (here equipment means electrical devices such as power transformers) one notices that starting in the range of switching overvoltages, and especially for lightning over voltages, the equipment insulation cannot withstand the occurring dielectric stresses. At this point, the arresters intervene. When in operation, it is certain that the voltage that occurs at the terminal of the device - while maintaining an adequate safety margin - will stay below the withstand voltage. Arresters’ effect, therefore, involves lightning and switching over voltages.
The time axis is roughly divided into the range of lightning overvoltage (microseconds), switching overvoltages (milliseconds), temporary overvoltages (seconds) – which are commonly cited by the abbreviation "TOV" – and finally the temporally unlimited highest continuous system operation voltage.
This document summarizes types of lightning arresters, their classification, identification, standard ratings, and service conditions. There are three main types of arresters: expulsion, valve, and gapless metal-oxide. Arresters are classified into four classes based on their nominal discharge current and use: station, intermediate, distribution, and secondary. Arresters must be properly identified and can operate under normal conditions of temperature, radiation, altitude, and frequency, but may require special consideration under abnormal conditions.
Over voltages can be caused by internal factors like switching operations or insulation failures, or external factors like lightning. Lightning arrestors protect equipment by diverting high voltage surges to ground. They break down temporarily during over voltages and regain insulation at normal voltages. Insulation coordination determines equipment insulation strength to withstand normal operating voltages and temporary over voltages based on factors like highest system frequency, temporary over voltages, and transient surges. Equipment is tested and rated with a basic insulation level to ensure it can withstand impulse voltages above that level.
A surge diverter protects electrical equipment from voltage surges by diverting excess voltages caused by spikes in the electrical supply to earth. There are different types of surge diverters, including rod gap, protector tube, and valve type diverters. Rod gap diverters consist of two rods with a gap that sparks over during a surge to discharge current to ground. Protector tube diverters improve on rod gaps by enclosing the gaps to extinguish follow-on arcs. Valve type diverters incorporate non-linear resistors to provide a low resistance path for surges while blocking normal voltages and currents.
Superconductivity is a phenomenon where materials exhibit zero electrical resistance and expel magnetic fields when cooled below a critical temperature. It is characterized by the Meissner effect, where superconductors push out magnetic fields. Superconductors can carry direct electric currents without resistance, allowing the current to flow undiminished forever. The crystal structures of high-temperature superconductors contain copper-oxide layers. Type I superconductors exhibit a sudden transition from the superconducting to normal state at a critical magnetic field, while type II superconductors can be penetrated by magnetic fields and are useful for applications. Superconductors have applications in power transmission, telecommunications, transportation, computing, medical imaging and other areas.
This document discusses using superconductors for surge current protection in power systems. It begins with an introduction to surge currents and superconductors. Superconductors conduct electricity with zero resistance below a critical temperature. There are two main types of superconductors: low-temperature and high-temperature. Fault current limiters (FCLs) use superconductors to limit surge currents during faults. FCLs come in resistive and inductive varieties. FCLs can protect equipment by limiting current flow and extending component lifetimes. Future applications include installing FCLs at transmission voltages of 500kV. Superconducting FCLs offer efficient protection for power systems.
Surge current protection using superconductor ppt maheshKuldeep Singh
This seminar discusses using superconductors for surge current protection. Superconductors conduct electricity with zero resistance below a critical temperature. They can be used as fault current limiters to protect power systems when faults occur. Two main types of superconductor fault current limiters are resistive and inductive. Superconductive fault current limiters offer advantages like safety, reliability, and extended equipment life. Future plans include developing three-phase limiters for testing on power grids this century. Superconductive fault current limiters have applications in transmission and distribution systems.
This document provides guidance on electrical insulation testing. It discusses what constitutes good insulation, how insulation resistance is measured using a Megger insulation tester, and different types of insulation resistance tests including short-time or spot-reading tests and time-resistance tests. Factors that can affect insulation resistance readings, such as temperature, humidity, and the length of time voltage is applied, are also covered.
Surge arrestors are protective devices that limit voltage spikes and surges from damaging electrical equipment. They work by diverting excess current during events like lightning strikes or power faults to ground. When voltage increases, the resistor inside the arrestor decreases in resistance, allowing extra current to drain out and prevent voltage from increasing in protected equipment. Surge arrestors are installed at substations and near transformers to shield sensitive equipment from voltage transients. They parallel arrangement allows surges to be discharged without propagating through the system.
The Different Types of Inductors and Their Affecting Factorselprocus
An inductor is also named as a reactor, coil and choke. It is a two terminal electrical component used in various electrical and electronic circuits. An inductor is used to store energy in the form of a magnetic field. Learn the different types of inductors and their affecting factors and have a wide variety and important applications in electronics.
This document provides an overview of electric power systems, including their history and basic concepts. It discusses how electric power systems evolved from early experiments in the 18th century through the development of generators, transformers, and interconnected grids. The key concepts of voltage, current, power, energy, direct current, alternating current, frequency, and the three types of loads - resistive, inductive, and capacitive - are explained. Today's electric power systems generate power, transmit it over high-voltage lines, transform the voltage, and distribute power to homes and businesses in real-time as it is consumed.
Brief information of Electricity and wiring Mani Das
Electricity is a form of energy involving the flow of electrons. Benjamin Franklin first invented electricity and studied it, while Alessandro Volta discovered that chemical reactions can produce electricity and invented the first battery. Electricity can be generated through various means like heat, falling water, wind, solar, and chemical energy. There are two types of electric current: direct current where electrons flow in one direction and alternating current where electrons repeatedly change direction. Electricity has many applications like powering homes and industry as well as operating machines.
The document provides an overview of how electricity works. It explains that electricity is the flow of electrons through conductors. Materials like metals have free electrons that allow electricity to flow, while insulators do not. Generators use magnets to induce electron flow, creating electricity. Electrical circuits require a power source, conductor, and load to provide a complete path for electrons to flow through. The voltage pushes electrons through the circuit, while current is the flow of electrons and resistance impedes their flow. Alternating current produced by power plants flows back and forth rather than one direction.
Current Electricity Chp-8 General Science 9th 10thKamran Abdullah
Subject : General Science
Teacher: Mr Ehtisham Ul Haq
Class: BS EDUCATION
Semester: 2nd (Spring(2023-2027)
Date Of Starting Of Semester : 4 September 2023
Date Of End Of Semester : 20 January 2024
University Of Sargodha
Institute of Education
These are the presentation slides that we prepare by our own research and work!
This document provides an outline for a course on electromagnetism, electricity, and digital electronics. It covers topics such as the theory of electrons and atoms, resistors, circuits, magnetism, diodes, logic gates, and combinational and sequential circuits. References provided include textbooks on digital design, electronic devices, engineering circuit analysis, and introductions to electric circuits and digital circuits. The document also includes sections on electron theory, atomic structure, conductors and insulators, sources of electricity, alternating and direct current, voltage, current and resistance, and Ohm's law.
This document provides an outline for a course on electromagnetism, electricity, and digital electronics. The course covers topics such as the theory of electrons and electricity, resistors, Ohm's law, circuits, magnetism, diodes, logic gates, combinational and sequential circuits. References for the course include textbooks on digital design, electronic devices, engineering circuit analysis, and introductions to electric circuits and digital circuits. The document also provides details on some of the topics, including the theory of electrons, insulators/conductors/semiconductors, direct and alternating current, voltage, current, resistance, and Ohm's law.
Electricity is produced by the flow of electrons through a conductor. It is a vital resource that powers economic growth and development. There are natural and artificial sources of electricity. In automobiles, the main source is a storage battery, which is kept charged by an alternator. The basic units of electricity are electrons, voltage, current, resistance, and watts. Voltage is the force that pushes electricity through a wire, current is the flow of electrons, and resistance restricts this flow. Power in watts is calculated by multiplying amps times volts. Understanding these basic concepts is key to working with electrical systems.
POWER SYSTEM INTRODUCTION priyank pulkit rads praveerPRIYANK JAIN
The document provides an overview of the electricity sector in India. It discusses how electricity has become essential to modern life and the Indian economy. It then summarizes the history and development of the electricity sector in India, including key milestones like the 1991 reforms that opened the sector to private investment and the 2003 Electricity Act. The document also provides explanations of basic electricity concepts like voltage, current, power, frequency, as well as different components of the power system like generation, transmission, distribution and utilization.
The document provides an overview of basics of electricity including:
1) A brief history of electrical power systems and key inventors like Thomas Edison, Frank Julian Sprague, Nikola Tesla, and William Stanley.
2) Descriptions of electrons, protons, voltage, current, resistance, and basic electric circuits.
3) Explanations of conductors, insulators, electromagnetic fields, and other fundamental concepts.
Electricity is produced when electrons move between atoms. It is everywhere in electrical outlets, batteries, and static electricity from rubbing your feet on carpet. An electric circuit allows electrons to flow continuously from a power source like a battery through a conductor like a wire back to the source. Conductors freely allow electron movement while insulators do not, preventing shocks. Electricity can be static and stay in one place or use current to flow through closed circuits in appliances, creating alternating currents.
WHY ELECRICITY IS IMPORTANT ?
Electricity is an essential part of modern life. People use electricity for lighting, heating, cooling, and refrigeration and for operating appliances, computers, electronics, machinery, and public transportation systems.
Electrical energy is one of the most commonly used forms of energy in the world. It can be easily converted into any other energy form and can be safely and efficiently transported over long distances. As a result, it is used in our daily lives more than any other energy source.
Benjamin Franklin and Thomas Edison were important figures in the development of electricity. Franklin proved that lightning was electricity and helped people understand electrical principles, while Edison invented the light bulb. The document goes on to define key electrical concepts like current, voltage, resistance and different types of circuits. It also describes different sources of electricity like power stations and batteries, as well as instruments used to measure current and voltage.
This document discusses electricity and magnetism. It provides historical context on the discovery of electricity from rubbing amber. It describes the basic components that make up atoms and how they relate to electric charge. Key topics covered include electric charge, electrostatic forces, circuits, batteries, conductors vs insulators, resistance, voltage, capacitors, and Ohm's law. Formulas for resistance, capacitance, and calculating electrical power are also presented.
This document provides information about electrostatics and related concepts:
- Electrostatics is the study of static electricity and involves the forces between electrically charged particles at rest. Thales of Miletus discovered static electricity by observing that rubbing amber with wool caused it to attract small particles.
- There are two types of electric charge: positive and negative. Electrons carry a negative charge while protons carry a positive charge. Materials become positively charged when electrons are removed and negatively charged when electrons are added.
- Coulomb's law describes the electric force between two charged particles. It states that the force is directly proportional to the product of the charges and inversely proportional to the square of the distance between them.
Current Electricity Chp-8 General Science 9th 10thKamran Abdullah
Subject : General Science
Teacher: Mr Ehtisham Ul Haq
Class: BS EDUCATION
Semester: 2nd (Spring(2023-2027)
Date Of Starting Of Semester : 4 September 2023
Date Of End Of Semester : 20 January 2024
University Of Sargodha
Institute of Education
These are the presentation slides that we prepare by our own research and work!
This document discusses the history and development of high voltage engineering. It begins with early experiments with static electricity by ancient Greeks. Key figures who contributed include Franklin, Faraday, Tesla, and Edison. Faraday's law established that a magnetic field can induce current in a wire. Advances allowed longer distance power transmission. Challenges included developing high voltage insulation. Numerical methods like finite element analysis are now used to model electric field distributions in complex high voltage components.
Some slides here were disorganized although I uploaded it on its good condition. Maybe some compression? or what? Howsoever, I think that it's readable and understandable enough.
Similar to Electrical basic engineering by Ramesh meti karanataka (20)
Motors use electromagnetic induction to convert electrical energy into mechanical energy. AC motors have a stationary stator and rotating rotor that interact via magnetic fields generated by alternating currents. DC motors consist of an armature winding and stator winding, with the armature acting as the rotor. Motor starters are used to control motor speed and current during starting to prevent damage. Common motor starters include magnetic, full-voltage, reversing, reduced-voltage, and solid-state starters. Reduced-voltage starters gradually apply voltage during starting for smoother acceleration.
A DC motor converts electrical energy into mechanical energy using the principles that a current carrying conductor placed in a magnetic field experiences a force. It has a stator that houses field windings and a rotor that rotates. There are different types of DC motors including separately excited, series, shunt, and compound motors. Series motors have high starting torque but low speed regulation while shunt motors have low starting torque but good speed regulation, making each suitable for different applications.
1) The document discusses the key parts of a DC generator, including the yoke, pole core, field coils, armature core, armature winding, commutator, brushes and brush holders, and bearings.
2) It describes the function of each part, with the yoke providing a low reluctance path for magnetic flux, the field coils producing flux when excited, the armature winding placed in slots on the armature core, and the commutator facilitating current collection from the armature conductors.
3) The class covered the purpose of each generator component and conducted a quiz to test comprehension.
The document discusses the working principle of a DC generator. It explains that a DC generator converts mechanical energy to electrical energy using electromagnetic induction. When a conductor moves through a magnetic field, an induced current is generated based on Faraday's law of induction. The direction of the induced current can be determined using Fleming's right hand rule. The document then describes how a rectangular loop of conductor rotating inside a magnetic field cuts the magnetic flux, generating an induced current that changes direction based on the loop's position. A commutator is used to ensure the output current flows continuously in one direction to the load.
The document discusses the universal motor, which can operate on both AC and DC power. It has a series-wound construction similar to a DC motor but with laminated magnetic components to reduce eddy currents from AC power. Universal motors are commonly used in appliances like drills, fans, and blenders because they can function using both AC household power and portable DC batteries. The document covers the construction, working principle, characteristics, and common defects of universal motors.
- A Direct On Line (DOL) starter connects the motor directly to the power supply. It consists of fuses, an isolator, contactor, and overload protection. Pressing the start button energizes the contactor coil to close the contacts and start the motor.
- A reversing DOL starter uses two contactors to reverse the motor direction by swapping the phase connections. It has separate start buttons for forward and reverse operation.
- A star-delta starter reduces starting current by initially connecting the motor in star configuration before switching to delta. This allows the motor to start smoothly before applying full voltage once up to speed.
The document provides information about DC motors, including:
- The construction of a DC motor, which includes an armature mounted on a shaft within magnetic poles that provide torque.
- How DC motors work by applying current to the armature within a magnetic field to produce rotational force, with the magnitude of force determined by Fleming's left hand rule.
- Different types of DC motor windings including series, shunt, and compound, and how they affect torque characteristics like starting torque.
- How speed can be controlled through armature or field control, and various losses that occur in DC machines.
1. This document provides an introduction to using formulas and functions in Excel, including the basics of adding, subtracting, multiplying, and dividing in Excel without functions, as well as an overview of more advanced functions like SUM, TODAY, COUNT, and AVERAGE.
2. Key functions introduced include SUM, which totals the values in a range of cells; TODAY, which returns the current date; COUNT, which counts the number of cells in a range that contain numbers; and AVERAGE, which calculates the average of the values in a range.
3. The document explains best practices for using formulas with cell references rather than hard-coded values to allow for easy updating, and demonstrates how to enter functions
This document lists 50 keyboard shortcuts in Excel for Windows for navigating cells, making selections, formatting cells, and other frequently used shortcuts. Some examples include using Page Down to move down one screen, Ctrl + Home to go to the beginning of the worksheet, Ctrl + End to go to the last cell, and Ctrl + S to save a spreadsheet.
This document provides information on power projects in Karnataka operated by KPCL, including:
1) Existing projects totaling 6,498.91 MW from hydro (3,652.35 MW), thermal (2,720 MW), diesel (108 MW), wind (4.56 MW), and solar (14 MW).
2) Ongoing projects totaling 2,325 MW from thermal and hydro.
3) New projects totaling 3,120 MW planned from thermal, hydro, and gas.
4) Proposed new projects totaling 3,895 MW planned from hydro and gas.
Sri M. S. Suresh, S. I. Gr. II
Sri M. S. Suresh, S. I. Gr. II
Sri M. S. Suresh, S. I. Gr. II
Sri M. S. Suresh, S. I. Gr. II
Sri M. S. Suresh, S. I. Gr. II
Sri M. S. Suresh, S. I. Gr. II
Sri M. S. Suresh, S. I. Gr. II
Sri M. S. Suresh, S. I. Gr. II
Sri M. S
The document is the Kalaburagi District at a Glance report for 2016-17 published by the District Statistical Office, Kalaburagi.
The report provides key statistics on the district's demography, economy, infrastructure like education, health and transportation. It includes data on population, births and deaths, crops, livestock and other socio-economic indicators. The performance is compared to other districts in the state.
The report was prepared under the guidance of senior statistician Dr. D.R. Suresh, District Statistical Officer, Kalaburagi and other staff of the District Statistical Office for planning purposes.
The document discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive functioning. Exercise causes chemical changes in the brain that may help protect against mental illness and improve symptoms.
This document appears to be a price list from Schneider Electric for its low voltage distribution products. It includes pricing and descriptions for various circuit breakers, switch disconnectors, and accessories. The products are organized by category and range, with sections devoted to Compact NSXm circuit breakers, EasyPact CVS and EZC circuit breakers, ground fault protection devices, Masterpact circuit breakers, and more. Technical specifications, stock statuses, and contact information for ordering are provided.
This document is a price list from Schneider Electric that provides pricing and product information for various electrical distribution and control products effective January 18, 2019. It includes pricing for miniature circuit breakers, residual current devices, surge protection devices, wiring devices, plugs and sockets, enclosures, and lighting and building control systems. The price list provides product references, unit prices, minimum order quantities and other specifications.
The document discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive function. Exercise causes chemical changes in the brain that may help protect against mental illness and improve symptoms for those who already suffer from conditions like anxiety and depression.
The document provides various tips to save energy in lighting, fans, kitchen appliances, washing machines, air conditioners and electronic devices. Some key tips include:
- Turn off lights and use natural daylight when possible. Replace incandescent bulbs with LED bulbs which last longer.
- Install electronic regulators for ceiling fans and place exhaust fans at a higher elevation than ceiling fans.
- Use appliances with automatic cutoffs and energy efficient settings. Avoid preheating microwaves unnecessarily.
- Only run full loads in washing machines and dryers. Air dry clothes when possible.
- Turn off electronic devices when not in use to avoid idle energy loss. Adjust monitor brightness settings.
- Seal air conditioner
The document is a scanned receipt from a grocery store purchase on January 15th, 2023 for $58.46. It lists the items bought which include milk, eggs, bread, cereal, orange juice, bananas, and ground beef. The payment was made with a credit card ending in 4321.
CHINA’S GEO-ECONOMIC OUTREACH IN CENTRAL ASIAN COUNTRIES AND FUTURE PROSPECTjpsjournal1
The rivalry between prominent international actors for dominance over Central Asia's hydrocarbon
reserves and the ancient silk trade route, along with China's diplomatic endeavours in the area, has been
referred to as the "New Great Game." This research centres on the power struggle, considering
geopolitical, geostrategic, and geoeconomic variables. Topics including trade, political hegemony, oil
politics, and conventional and nontraditional security are all explored and explained by the researcher.
Using Mackinder's Heartland, Spykman Rimland, and Hegemonic Stability theories, examines China's role
in Central Asia. This study adheres to the empirical epistemological method and has taken care of
objectivity. This study analyze primary and secondary research documents critically to elaborate role of
china’s geo economic outreach in central Asian countries and its future prospect. China is thriving in trade,
pipeline politics, and winning states, according to this study, thanks to important instruments like the
Shanghai Cooperation Organisation and the Belt and Road Economic Initiative. According to this study,
China is seeing significant success in commerce, pipeline politics, and gaining influence on other
governments. This success may be attributed to the effective utilisation of key tools such as the Shanghai
Cooperation Organisation and the Belt and Road Economic Initiative.
Harnessing WebAssembly for Real-time Stateless Streaming PipelinesChristina Lin
Traditionally, dealing with real-time data pipelines has involved significant overhead, even for straightforward tasks like data transformation or masking. However, in this talk, we’ll venture into the dynamic realm of WebAssembly (WASM) and discover how it can revolutionize the creation of stateless streaming pipelines within a Kafka (Redpanda) broker. These pipelines are adept at managing low-latency, high-data-volume scenarios.
Comparative analysis between traditional aquaponics and reconstructed aquapon...bijceesjournal
The aquaponic system of planting is a method that does not require soil usage. It is a method that only needs water, fish, lava rocks (a substitute for soil), and plants. Aquaponic systems are sustainable and environmentally friendly. Its use not only helps to plant in small spaces but also helps reduce artificial chemical use and minimizes excess water use, as aquaponics consumes 90% less water than soil-based gardening. The study applied a descriptive and experimental design to assess and compare conventional and reconstructed aquaponic methods for reproducing tomatoes. The researchers created an observation checklist to determine the significant factors of the study. The study aims to determine the significant difference between traditional aquaponics and reconstructed aquaponics systems propagating tomatoes in terms of height, weight, girth, and number of fruits. The reconstructed aquaponics system’s higher growth yield results in a much more nourished crop than the traditional aquaponics system. It is superior in its number of fruits, height, weight, and girth measurement. Moreover, the reconstructed aquaponics system is proven to eliminate all the hindrances present in the traditional aquaponics system, which are overcrowding of fish, algae growth, pest problems, contaminated water, and dead fish.
Presentation of IEEE Slovenia CIS (Computational Intelligence Society) Chapte...University of Maribor
Slides from talk presenting:
Aleš Zamuda: Presentation of IEEE Slovenia CIS (Computational Intelligence Society) Chapter and Networking.
Presentation at IcETRAN 2024 session:
"Inter-Society Networking Panel GRSS/MTT-S/CIS
Panel Session: Promoting Connection and Cooperation"
IEEE Slovenia GRSS
IEEE Serbia and Montenegro MTT-S
IEEE Slovenia CIS
11TH INTERNATIONAL CONFERENCE ON ELECTRICAL, ELECTRONIC AND COMPUTING ENGINEERING
3-6 June 2024, Niš, Serbia
Redefining brain tumor segmentation: a cutting-edge convolutional neural netw...IJECEIAES
Medical image analysis has witnessed significant advancements with deep learning techniques. In the domain of brain tumor segmentation, the ability to
precisely delineate tumor boundaries from magnetic resonance imaging (MRI)
scans holds profound implications for diagnosis. This study presents an ensemble convolutional neural network (CNN) with transfer learning, integrating
the state-of-the-art Deeplabv3+ architecture with the ResNet18 backbone. The
model is rigorously trained and evaluated, exhibiting remarkable performance
metrics, including an impressive global accuracy of 99.286%, a high-class accuracy of 82.191%, a mean intersection over union (IoU) of 79.900%, a weighted
IoU of 98.620%, and a Boundary F1 (BF) score of 83.303%. Notably, a detailed comparative analysis with existing methods showcases the superiority of
our proposed model. These findings underscore the model’s competence in precise brain tumor localization, underscoring its potential to revolutionize medical
image analysis and enhance healthcare outcomes. This research paves the way
for future exploration and optimization of advanced CNN models in medical
imaging, emphasizing addressing false positives and resource efficiency.
Using recycled concrete aggregates (RCA) for pavements is crucial to achieving sustainability. Implementing RCA for new pavement can minimize carbon footprint, conserve natural resources, reduce harmful emissions, and lower life cycle costs. Compared to natural aggregate (NA), RCA pavement has fewer comprehensive studies and sustainability assessments.
Introduction- e - waste – definition - sources of e-waste– hazardous substances in e-waste - effects of e-waste on environment and human health- need for e-waste management– e-waste handling rules - waste minimization techniques for managing e-waste – recycling of e-waste - disposal treatment methods of e- waste – mechanism of extraction of precious metal from leaching solution-global Scenario of E-waste – E-waste in India- case studies.
Advanced control scheme of doubly fed induction generator for wind turbine us...IJECEIAES
This paper describes a speed control device for generating electrical energy on an electricity network based on the doubly fed induction generator (DFIG) used for wind power conversion systems. At first, a double-fed induction generator model was constructed. A control law is formulated to govern the flow of energy between the stator of a DFIG and the energy network using three types of controllers: proportional integral (PI), sliding mode controller (SMC) and second order sliding mode controller (SOSMC). Their different results in terms of power reference tracking, reaction to unexpected speed fluctuations, sensitivity to perturbations, and resilience against machine parameter alterations are compared. MATLAB/Simulink was used to conduct the simulations for the preceding study. Multiple simulations have shown very satisfying results, and the investigations demonstrate the efficacy and power-enhancing capabilities of the suggested control system.
2. HISTORY AND BASICS OF
ELECTRICITY
Introduction
Although man has been aware of electricity for several centuries, a
proper scientific understanding of it began only in the 18 th century. In
this session, we will learn about the history of electricity and its basics.
History of Electricity
Around 600 BC,Thales, a Greek philosopher, discovered frictional
electricity. In 1600 AD, William Gilbert, an English physicist, coined the
word „electrical‟(Latin word derived from the Greek word electron. In 1646,
Sir Thomas Brown, an English writer, modified the term to „electricity‟. In
1800, Alessandro Volta, an Italian scientist, discovered a chemical form
of producing electricity. In 1831, Dr Michel Faraday, an English scientist
(also known as the „father of electricity‟), discovered dynamic electricity
with electromagnetic Induction. He is also called as the ' father of the
electricity.'
3. when was electricity first used in
homes
In 1882 Edison helped form
the Edison Electric
Illuminating Company of
New York, which brought
electric light to parts of
Manhattan. But progress was
slow. Most Americans still lit
their homes with gas light
and candles for another fifty
years. Only in 1925 did half
of all homes in the U.S. have
electric power.
4. when was incandescent lamp
used
1879 After many
experiments, Thomas Edison
invented an incandescent
light bulb that could be used
for about 40 hours without
burning out. By 1880 his
bulbs could be used for 1200
hours. 1879 Electric lights
(Brush arc lamps) were first
used for public street
lighting, in Cleveland, Ohio.
5. Thomas Edison Born Thomas Alva Edison
February 11, 1847
Milan, Ohio, U.S.
DiedOctober 18, 1931 (aged 84)
West Orange, New Jersey, U.S.
Burial placeThomas Edison National
Historical Park
Nationality American
Education Self-educated Occupation
Inventor, businessman Years active
1877–1930
Spouse(s)Mary Stilwell
(m. 1871; d. 1884)
Mina Miller
(m. 1886)
Children6, including Madeleine Edison,
Charles Edison and Theodore Miller
Edison
Relatives Lewis Miller (father-in-
law)Signature
6. When was electricity used in india
Established Asia’s first – Hydro
Electric Power Station in
Shivanasamudram, on the banks of
river Cauvery during 1902.
Karnataka the first to embark on
Alternating current, when
Bangalore Citys lighting scheme
was completed. Karnataka had the
longest transmission line in the
world in 1902, from
Shivanasamudram to KGF,
covering a distance of 147 km and
it was the first state in the country
to conceive
7. Who is the father of Electricty
Michael Faraday
A self-taught scientist, Michael
Faraday (1791-1867) excelled in
chemistry and physics to
become one of the most
influential thinkers in history.
He's been called the "father of
electricity," (Nikola Tesla and
Thomas Edison also wear that
crown) and his appetite for
experimenting knew no bounds.
8. What is the speed of electricity per
second?
Therefore, the speed of
electricity in a 12-gauge
copper wire is
299,792,458 meters per
second x 0.951 or
285,102,627 meters per
second. This is about
280,000,000 meters per
second.
2,80000km/sec
9. The Law of Conservation of Energy
The Law of Conservation of Energy states
that energy cannot be created or
destroyed; it can only be changed from
one form to another.
Sources of Electrical Energy
Water, Sun, Coal, Fuels, Nuclear, Wind
10. PRINCIPLES OF ELECTRICITY
Introduction
Electricity has become an integral part of
our lives. It is essential for lighting, power,
air conditioning, refrigeration and a host of
other applications. Life without electricity is
almost unimaginable. We must therefore have a
fair knowledge of the principles of electricity.
11. What is electricity?
What is electricity?
Electricity is an invisible and untouchable form of energy. But it can felt through its effects.
The components of electricity are current, voltage and resistance.
Current
Current is defined as the free flow of electrons through a conductor, which is measured by an
Ammeter, measuring unit is Amps and letter represented by I.
Voltage
Voltage is an electrical pressure required to drive free flow of electrons through a conductor.
It is measured by a voltmeter; measuring unit is volts and letter represented by V or E.
Resistance
Resistance is the property of a material which opposes free flow of electrons through it. It is
measured by an ohmmeter; measuring unit is ohms and letter represented by R.
12. How electricity gets to your home
Electricity starts its life in a power station.
Power stations are huge plants – often
located near energy sources like natural gas
plants, hydroelectricity dams, and solar or
wind farms – that produce electricity.
Depending on the type of fuel or source of
energy input - whether it’s coal, solar, wind,
or even nuclear - power plants may have
components such as a furnace, boiler,
turbine, cooling towers, and generators.
These types of components are essential for
the generation process.Once the electricity is
generated, it leaves the power station
through overhead lines to large substations.
At this stage, the electricity can be at as high
as 25,000 volts or ever higher.
POWER STATION
14. First substation transformer
Substations are usually located near
power stations. Substations play an
important role in the electricity
transmission process: they further
increase the voltage of the current,
allowing it to be sent over long
distances without losing too much
power. Substations do this by using
transformers, and these can be used to
either increase or decrease the voltage
of electric currents. Decreasing the
voltage of electricity can be important
at distribution substations as it needs
to be made less powerful and safe
before it enters your house.
Once it passes through the first
substation transformer, your electricity
makes its way to the transmission
networks.
15. Transmission networks
The transmission networks help
shift electricity from power
stations on to distribution networks
to facilitate delivery to households,
businesses, and other end users. At
this stage, the electricity remains at
a high voltage since it still needs to
move across vast distances.
The transmission networks are
made up of overhead lines on
metal pylons or lines buried under
the ground. These lines are
designed to carry ultra-high
voltages and they’re insulated to
prevent the electric current from
accidentally moving to the ground,
where it can be dangerous for
people.
16. 220kv substation transformer
At the second substation transformer point,
your electricity is reduced in voltage, again
through the use of transformers, to make it
safe for use by households and end users. At
this point the electricity is considered to
have reached the distribution network and
left the transmission network.
The type of substation and voltage can vary
depending on the use and location. For
example, in rural areas, smaller substations
might be used to reduce the voltage to
around 33,000 volts, which makes it suitable
for powering trains and factories. In urban
areas with factories, the voltage could range
between 11,000 and 33,000 volts to serve
smaller factories. Contrast with delivery to
homes, offices, and business, where the
neighbourhood transformer might lower the
voltage to as little as 230 volts.
17. Distribution powerlines
Once your electricity leaves the
substation transformer, it enters
distribution power lines on its way
to the final destination. Power
lines can be overhead or
underground, and they’re a
familiar sight in most areas around
Australia. Once it reaches your
neighbourhood, the electricity
passes through a small pole-top
transformer for another voltage
reduction. This ensures it’s safe to
use inside the home, office, or
business.
18. Your home
Your electricity passes through the service
drop and gets recorded at your metre. The
metre tracks how much electricity you
use. At your switchboard, your electricity
gets divided up into circuits for each area
of your house. Finally, the electricity
moves through wires behind your walls to
power outlets and switches, where you
operate your lights and appliances.
It’s easy to take the electricity used to
light your house for granted, but this
precious energy source has travelled a
long way, through complex generation
and transmission infrastructure, to get to
your house. Knowing this, you’re
probably less likely to take electricity for
granted when you next switch on your
light or power up the TV.
19. EFFECTS OF ELECTRIC
CURRENT
Introduction
As we discussed earlier, electricity is an invisible form
of energy that can be perceived only
through its effects. Whenever current flows
through a conductor, it is actually electrons
flowing from one place to another. It is not possible to
see the electrons or current flow. So it
is essential to know about the effects of electric
current.
20. Effects of Electricity
Physical effect: The human body is a good conductor of
electricity. So when we touch an object through which
current is flowing, we get a shock. Severe shock may even
lead to death (examples through case studies, activity,
etc.)
Heating effect: Whenever current passes through any
conductor, heat is produced in
that conductor. Such effect is used in a heater, press, lamps,
soldering iron, etc.
(activity based experiment)
21. Effects of Electricity
Magnetic effect: This effect is seen in fans, meters, calling
bells, etc. (demonstrate a calling bell)
Chemical effect: When current passes through an
electrolyte, a chemical reaction takes place. Battery charging
and electroplating are good examples.
X-ray effect: When high frequency is passed through a
vacuum tube, a special type of high-penetration rays come out,
which cannot be seen. They are called x rays; they are used to
take images of the insides of our body to diagnose diseases and
determine treatment.
22. POWER AND ENERGY
Power
Power is the rate of doing work.
Power (P) = Work done (W) / Time taken (T)
The unit of power is joules / second or watts /
second. I kilowatt (kW) = 1000 w
Another unit of power is hp; 1 hp = 746 w, or 1.34 hp in MKS system; 1 kW = 1.36 hp
Energy
Energy is the capacity for doing work. Energy exists in several forms, which
may be
interchanged.
1 joule = 1 Newton / meter A small unit of power is watt / second
A bigger unit of power is kwh (also called (botu); 1 botu = 1000 w or 1 kwh
= 36,00,000 joules
23. Energy Calculation
S.
No
Name of point No. of points Load
1 Lamps 10 100w
2 Ceiling fans 8 75w
3 Electric heater 1 1500w
4 Motor 1.5 hp 1 2000w
Total load
24. SAFETY PRECAUTION
Introduction
Electricity helps us in many ways. But it can take a
lot more than it gives us, and can be dangerous if it is
not treated properly. So we need to be very careful while
working with the live supply.
Safety Precautions
Careful handling of electrical appliances, using
insulated hand tools, using correct rating fuses,
effective earthing.
Metallic parts, using of hand gloves, using rubber
mat, never tamper unnecessarily with live lines and
never use damaged appliances.
25. Causes of Electric Shock
Carelessness
Accidental
Over confidence
Lack of awareness / ignorance
Natural causes (lightning etc.)
Effects of Shock on the Human Body
On the brain, body, kidney, etc. (refer to text books)
The Severity of a Shock Depends on:
Duration of current flow
Amount of current
Path of flow of current -location
Type of energy and line voltage, etc.
An electric shock occurs by touching:
Phase and natural simultaneously
Phase conductor and standing on ground
A metallic part, when current is leaking.
26. CAUSES OF ELECTRIC FIRE, AND EQUIPMENT USED
TO CEASE FIRE
Introduction
When a conductor carrying electric current gets
overloaded, it heats up and softens the insulating
cable. This may lead to a short circuit and fire. It is
therefore important that we understand various types
of fire and how to put them out with fire
extinguishers.
27. Causes of electric fire
Fire is a chain of chemical reaction, caused by combustion of
inflammable material producing heat, light and smoke. The
reasons for a fire could be:
Improper / substandard cables for wiring
Short circuits
Overloading the equipment
Maintenance negligence
Inadequate / poor insulation
Lightning
28. S.
No
Type of
fire
Name of
fire
Source Fire
extinguishers
used
1 Class A Solid fires Wood, cloth paper A class fire
extinguishers
2 Class B Liquid fire Petrol, fuel Dry Chemical
Powder (DCP)
3 Class C Gas fire LPG gas Dry Chemical
Powder (DCP)
4 Class – D Metal Fire Sodium,
Magnesium
ABC Fire
extinguishers
5 Electrically Started
Fires (ESF)
Electrical
Fire
Electrically Starts ABC Fire
extinguishers,
CO2 Gas
29. Types of Fire Extinguishers
Soda acid, Water-CO2, Form-type, Dry Chemical Powder (DCP), CO2 gas,
ABC Powder Extinguisher
Pressurizing mechanism in a Fire Extinguisher
Gas cartridge (CO2, water)
Spot pressure (soda, acid, and gas)
Stored pressure (readily available)
Advantages of ABC Fire Extinguishers
Very easy to handle
Anybody can operate
Can be located at the level of pressure
Very economical and effective
Can be used for any type of fire (Class A / B / C)
Readily available with stored pressure
30. Current level
(Milli-
amperes)
Probable Effect on Human Body
1 mA
Perception level. Slight tingling sensation. Still dangerous
under certain conditions.
5mA
Slight shock felt; not painful but disturbing. Average individual
can let go. However, strong involuntary reactions to shocks in
this range may lead to injuries.
6mA - 16mA
Painful shock, begin to lose muscular control. Commonly
referred to as the freezing current or "let-go" range.
17mA - 99mA
Extreme pain, respiratory arrest, severe muscular contractions.
Individual cannot let go. Death is possible.
100mA -
2000mA
Ventricular fibrillation (uneven, uncoordinated pumping of the
heart.) Muscular contraction and nerve damage begins to
occur. Death is likely.
> 2,000mA
Cardiac arrest, internal organ damage, and severe burns. Death is
probable
31. Minimizing Electrical Hazards
• Grounding/Earthing
• Guarding
• Locking and Tagging Equipment
• Mechanical Protection Devices
• Protective gears and clothing
• Plugs and receptacles
• Inspect Electrical Equipment before use
• Cable Routing
32. CONDUCTORS AND
INSULATORS
Introduction
Conductors and insulators play a vital role
in domestic / industrial wiring, including
networking systems. While conductors carry
the current, insulators provide safety for it. It is
important to understand them well.
33. Introduction to conductor and Insulator
Conductor: A material which contains many free electrons and is
capable of carrying electric current is known as a conductor.
Properties of a conductor:
Have a law specific resistance
Are mechanically rigid
Should be easily available
Should not be very expensive
Should be non corrosive
Should be ductile
Should be durable, malleable
Should have high stencil power
Should be highly conductive
34. DIFFERENT CONDUCTORS
USED FOR HOUSE WIRING
SYSTEM
Introduction
The conductor of a cable is like the heart of the human
body. The function of the conductor is to carry
current, like the heart circulates blood in the body. If
the blood circulation is irregular and improper, it may
cause various diseases in the body. Similarly if the
conductor (copper) is not good, due to reasons like
impurity of copper or improper bunching, the current
carrying capacity of the conductor will reduce. So we
need to use good conductors.
35. Types of wires used in domestic and industrial
According to the core
Single core wire
Two core wire
Three core wire
Four core wire
According to insulation (Stand wires)
VIR wire
CTS or TRS wires
PVC wires
FRLC
HFFR
Weather proof wires
Enameled wire
Fire resisting etc.
According to the metal
Bare Copper
ACSR Conductor
Fuse wire
Nichrome wires
36. The main criteria for selection of Cables
Voltage grade for house wiring 1100 V, 1.1 KV grade
Current rating of cables Voltage drop in cables on
current flow Short circuit withstanding capacity
Derating or safety load etc.
Avoid using obsolete British standard cables such as
1 / 18, 3 / 20 etc.
ISI recommends the use of metric system such as, 1.5
sq mm, 2.5 sq mm, 4 sq mm, 6 sq mm, 10 sq mm
37. Flow color codes for wiring (as shown in the picture)
o Green – Earthing
o Black – Neutral
o Red, Yellow, Blue – Phases
Abbreviations
CTS : Cab Tire Sheathed
VIR : Vulcanized Indian Rubber
PVC : Poly Vinyl Chloride
ETP : Electrolytic Tough Pitch
FRLS : Fire Retardant Low Smoke
HFFR : Halogen Free Flame Retardant
Conclusion
There is a need to give examples of many case studies, conventional cables and fire
retardant cables to the aspirants. Technicians should recognize the quality of a
conductor by seeing it.
38. The following points must be considered before selecting a particular wiring.
1. Durability: The wiring must be able to withstand wear & tear under any
circumstances.
2. Safety: The wiring must be able to provide safety by safely concealing
the wiring systems.
3. Mechanical Protection: Conduit wiring must be protected from damage through
physical or natural changes during its use.
4. Appearance: Appearance is the most important aspect to consider from the
architectural point of view.
5. Permanency: The wiring must not be affected by weather, smoke, dampness etc.
6. Accessibility: In the wiring system facility for the extension or renewal or
attraction should provided. he wiring must be done in a way that makes distribution
of power easy, without any hassles.
7. Cost: The wiring system adopted must be economically suitable to the client.
39. ISI recommends conductor
ISI recommends the use of metric system of wires as
given below:
a. 1.0 Sq mm b. 1.5 Sq mm c. 2.5 Sq mm
d. 4 Sq mm e. 6 Sq mm f. 10 Sq mm
Note: Obsolete British standard cables are 1/18, 3/20,
7/20 etc.
40. ELECTRICAL ACCESSORIES
Switches, Sockets
House wiring accessories can be classified into the following categories:
a. Control and distribution system
b. Cable carrier and support system
c. Current carrying conductors (wires)
d. Switching and termination products
e. Sensor Switches
Control (Protection) and distribution system
This system is used to control the main supply and distribute it to the circuits. The main
protective devices used in house wiring circuits are:
i. Fuses (Fuse that can be re-wired, HRC Fuses available at diff ranges [6Amp to 200Amp])
ii. ICDP, ICTP (available at 32A to 200A)
iii. Miniature Circuit Breakers (available at 1A to 40A)
iv. Isolator (available at 32A to 63A)
v. ELCB / RCCB – (available at 32A, 40A & 63A) and MCCB above 63A
All the above mentioned items are installed in control and distribution boards. The Boards are
available in 1 phase, 3 phase, single door and double door as shown in the picture.
41. Cable carrier and support
The house wiring cable can‟t be run or laid on walls without support. Hence the
wires need to be supported from the main distribution till the terminating product.
The systems used to carry, support and run these wires are called cable carriers and
support systems. The different systems which we adopt for the same are as follows:
i. Wooden capping & casing wiring
ii. Cleat wiring
iii. Conduit wiring (open/ surface)
iv. Conduit wiring (concealed)
Different accessories available to carry wires
i. PVC conduits available in 19 mm, 25 mm
ii. Junction Box – 1 way, 2 way, 3 way and fan hooks
iii. MS / GI conduits and its accessories such as MS inspection bend, Inspection „T‟ and
„J‟ boxes etc.
iv. The conduits are available in sizes of 16mm, 19mm, 25mm and 30mm and are
normally of 16 SWG thickness
v. Casing and capping batten patties are also available in different sizes for temporary
wiring
42. Switching and terminating products
All these products have certain common features like insulation bases and covers.
All the house wiring cables normally terminate in:
i. Switches (All types)
ii. Sockets
iii. Ceiling roses
iv. Holders and adaptors etc.
i. Switches:
Switches are classified as under:
1. According to the rating – 6 A, 10 A, 16A
2. According to the connection – 1 way, 2 way and intermediate
ii. Sockets:
1. According to the rating: 6A, 10A, 16A, 25A etc.
2. According to the connection: 2 pin, 3 pin, 5 pin, multi pin etc.
43. iii. Ceiling Roses:
The wiring from switch terminals is taken to ceiling roses, lamp holders and
connectors.
The ceiling roses are available in two types. These are 2 pin and 3 pin.
iv. Holders and Adaptors:
There are some other terminating products named as holder and adaptors.
Different holders are available in the market:
a. Angle Holder b. Batten Holder c. Pendent Holder
d. Screw type / Pin type Holder etc.
Sensor Switches:
Sensor switch is also similar to the switch but it works on sensor signals. It is a
small
electronic circuit. The sensor switches are as under:
a. Temperature sensor b. Light sensor
c. Dark sensor d. Sound sensor
e. Acoustic sensor f. Vibration sensor
g. Altitude sensor h. PIR (Passive Infrared) etc.
44. Stand by power sources: Power outages are very
common in all parts of the country which is why
standby power sources are very essential to fulfill the
power shortage. Standby power sources may be:
a. Alternators / Generators
b. UPS (Uninterrupted Power Supply) system
c. Inverter
d. Emergency lights etc.
45. The common conductors used for electrical purpose are:
Silver Copper Bronze
Brass Aluminum Lead
Tin Micromere Tungsten
Eureka Carbon etc.
Insulators: A substance which cannot pass current through it under normal conditions
is
termed as an insulator.
Properties of insulators:
Insulators:
Should have low conductivity
Should have a high specific resistance
Should have a resistance and ability to bear high temperatures
Should have a good mechanical strength
Should be moisture resistant and water proof
Should have a high dielectric strength (voltage bearing capacity)
Should be permanent in nature (remain in the same state and condition regardless of
the environmental conditions)
46. The common insulation used for
electrical uses:
• Bakelite, Porcelain, Mica , Rubber, Fiber, Vanish
Glass, Wood , Cotton tape ,PVC Oil
• Classifications of cables according to the insulator
used:
• VIR wires
• PVC wires
• Flexible wires
• Enameled wires
• Cotton covered wires
47. UNDER GROUND CABLES
Introduction
Electric power can be transmitted or distributed either by OHL or by underground
cables. The underground cables have several advantages, the only disadvantage
being the initial cost. Underground cables An underground cable essentially
consists of one or more conductors covered with suitable insulation and
surrounded by a protecting cover.
Construction of cables
The various parts of underground cables are as under
as shown in the picture.
a. Cores or conductors
b. Insulation
c. Metallic sheath
d. Bedding
e. Armoring
f. Serving
48. Insulating material for cables
The satisfactory operation of a cable depends to a
great extent upon the characteristics of insulation
used.
The principal insulating materials used in cables
are:
a. Rubber
b. Vulcanized Indian Rubber (VIR)
c. Impregnated paper
d. Varnished cambric
49. Classification of cables
Cables for underground service may be classified in two ways according to:
1. The type of insulating material used
2. The voltage for which they are manufactured According to the voltage
1. Low tension (LT) cable – up to 1000V
2. High tension (HT) cable – up to 11,000V
3. Super tension (ST) cable – up to 33 KV
4. Extra high tension (EHT) cable – 3 KV to 66 KV
5. Extra super voltage cable – beyond 132 KV
Cables for 3 phase service
1. Better cable – up to 11 KV
2. Screened cables – 22 KV to 66 KV
3. Pressure cable – Beyond 66 KV
51. Electricity today is playing an ever increasing role in the lives of
every human being. Increased use of electricity has resulted in
increased danger to human beings. When lightening occurs, it
not only damages consumer‟s premises but it also destroys
property and lives. So today Earthing is considered the
most
essential provision of any electric supply system. But
unfortunately it is the most neglected aspect in house
wiring and implement it on grounds. Hence today we discuss
about Earthing.
and in many cases even in industrial and commercial wiring. So
earthing is thus laid down as a statutory requirement in Indian
electricity rules so as a trainer / trainee we need to understand
and implement it on grounds. Hence today we discuss about
Earthing.
52. What is Earthing?
A wire coming from the ground 2.5m to 3m deep from an
electrode (Plate) is called Earthing.
A wire 2.5m to 3m long connected from an electrode
(plate) to the main switch board to
avoid shock is called Earthing.
Note: The metal plate, copper plate, rod or
conductor is called as earth electrode.
53. Purpose / Objects of Earthing
• To save human life from
Danger / shock
• To protect large buildings and
towers from lightening
• To protect all machines fed
from OH lines from lightening
arresters
• To maintain the line voltage
• To provide easy return path for
leakage current
• Good Earthing is that which
gives low resistance and enables
smooth flow of heavy
•current
54. Methods of Earthing
•There are mainly two methods of Earthing. They are:
•a. Plate Earthing (most common and effective method)
•b. Pipe Earthing
•ISI Rules
• The standard Earthing code is IS 3043
• The Earth pit must be 1 ½ m distance from the building wall
• The earth wire must be of the same material as that of the electrode used
• The cross sectional area of the earth wire should not be less than 8 SWG
• The size of the earth conductor should not be less than half the size of
the line
•conductor
• All the joints must be properly joint, bolted, soldered or brazed
• All the metal parts, motors, generators and other appliances must be
properly
•connected by the earth conductor
• All the third pin of sockets must be connected to earth conductor
• Every stay wire must be Earthed
55. Earthing
•Earthing.
•Necessary of earthing.
•Safety of earthing.
•Method of earthing.
•Plate earthing.``
•Pipe earthing.```
•Chemical earthing.
•Application of earthing.
•Recommended of earthing resistance value
56. •Bare copper condEarthing means copper
plate/cast iron plate with G.I plate to be
inserted in the ground. About 2.5 to 3
meters depth in the ground, &Earthing is
flow of leakage & excessive current.
•uctor is to be connected to plate & taken
out as earthing wire called earthing.
57. Safety of earthing
•danger of electric
shock.
• To protect building ,
machinery &
appliances & under
fault condition.
• To provide safe path
to neutraTo save the
human life from the
lize the access
voltage.
58. What is earthing and why it is
done?
Earthing is used to
protect you from an
electric shock. It does this
by providing a path (a
protective conductor) for a
fault current to flow to
earth. It also causes the
protective device (either a
circuit-breaker or fuse) to
switch off the electric
current to the circuit that
has the fault.
59. Which type of earthing is used in homes?
Electric earthing may be
either pipe or plate earthing.
Normally GI pipe (2.5 inch
diameter) or plate (500 mm
X 500 mm X 10 mm) is
used but if the soil is
corrosive then copper pipe or
plate should be used. Use
Double GI Strip size 30 mm
X 10 mm to connect GI Plate
to System Earthing.
60. Plate type earthing
Plate Earthing: A copper
plate or galvanized plate
is buried in an earth pit
below ground level. The
plate electrode connects
the electrical conductors to
the earth
61. •chemical earthing is consider more
effective solution for consistent &
permanent earthing.
•They are maintenance free & have
minimum fluctuations & are eco
friendly.
•In chemical earthing we use
bentonite powder
•They are highly reliable for safety
of human life.
Chemical earthing
63. Recommended of earthing resistance
value
• Earth resistance less
then 2 ohm’s
residential/commercial/i
ndustrial.
• For electronic
components
(computer/T.V/UPS) it
should be within 1ohm.
• if the results are out of
range needs to check &
rectify until it reaches
within the limits.
64.
65. `What is fuse explain?
In electronics and electrical
engineering, a fuse is an
electrical safety device that
operates to provide
overcurrent protection of an
electrical circuit. Its essential
component is a metal wire or
strip that melts when too
much current flows through
it, thereby stopping or
interrupting the current.
67. What is MCB and its function?
A miniature circuit breaker
(MCB) automatically
switches off electrical circuit
during an abnormal
condition of the network
means in overload condition
as well as faulty condition.
Nowadays we use an MCB
in low voltage electrical
network instead of a fuse. ...
Handling an MCB is
electrically safer than a fuse
68. Types of MCB
There are four types of
MCB
1 Pole MCB
2 Pole MCB
3 Pole MCB and
4 Pole MCB
69. Current Ratings of MCB
0.5 A
1 A
2 A
3 A
4 A
5 A
6 A
10 A
16 A
20A
25 A
32 A
40 A
50 A
63 A
70. Parts of MCB
A breaker is a device
designed to isolate a circuit
during an overcurrent event
without the use of a fusible
element. A breaker is a
resettable protective device
that protects against two
types of
overcurrent situations:
Overload and
Short Circuit.
71. Small circuit breakers are
either installed directly in
equipment, or are arranged in a
breaker panel. The design of
MCB includes the following
components:
1.Actuatorlever
2.Tripmechanism
3.Contacts
4.Terminals
5.Bimetallicstrip
6.Calibrationscrew
7.Solenoid
8.Arcdivider/Extinguisher
72. Thermal / Magnetic trip units
Current Limiting Breakers
use an electromechanical
(Thermal /Magnetic) trip
unit to open the breaker
contacts during a
overcurrent event. The
thermal trip unit is
temperature sensitive and the
magnetic trip unit is current
sensitive.
Both units act independently
and mechanically with the
breaker’s trip mechanism to
open the breaker’s contacts.
73. What is MCCB
Molded Case Circuit Breaker
(MCCB) is a circuit breaker
and trip device assembled in
a mould case. Also it can
automatically cut off electric
power in case of overload
and short circuit. It is meant
for higher rated current and
is commonly used in
Industrial applications. Its
usual range is 250A-800A.
74. Current rating of MCCB
15 A
20 A
30 A
40 A
50 A
60 A
75 A
100 A
125 A
150 A
175 A
200 A
225 A
250 A
300 A
350 A
400 A
500 A
630 A
700 A
800 A
1000 A
1200 A
75. MCB MCCB
Miniature Circuit Breaker Moulded Case Circuit Breaker
Rated current not more than 63
A.
Rated current up to 1000 A.
Trip current
normally not adjustable.
Trip current may be adjustable.
normally not adjustable.
Thermal or thermal-magnetic
operation.
Thermal or thermal-magnetic
operation.
which is used to break small
currents. Like in domestic LT
circuitz
which has a rugged
construction as it can break
larger currents usually from
(100-1000A).
For domestic purpose. For commercial and industrial
use.
Type of switch which protects
the system from overloaded
current.
Protects the equipment from
over temperature and fault
current.
76. RCB (Residual Current Circuit
Breaker)
While RCCB is a current
sensing electro-mechanical
device that breaks an electric
circuit and trip in case of the
earth fault.
Line (Phase or Live) and
Neutral (N) both wires are
connected to the load points
through RCCB (RCD)
It is only connected to Phase
and Neutral Wire.
77. Residual Current Circuit Breaker
If there is no connection
between the ground and the
enclosure of the device, and
a person touches the metallic
body of that device. In this
case, incoming and outgoing
current will be different and
RCB will Trip in contrast
with ELCB.
Functionality of RCB
(Residual Current Breaker)
does not effect by lightning
strikes.
It does not trip falsely.
78. ACB ( Air Circuit Breaker )
Air Circuit Breaker
(ACB) is an electrical
device used to provide
Over current and short-
circuit protection for
electric circuits over 800
Amps to 10K Amps. These
are usually used in low
voltage applications below
450V.
79. vacuum circuit breaker
A vacuum circuit breaker is a
kind of circuit breaker where the
arc quenching takes place in
vacuum medium. The operation of
switching on and closing of
current carrying contacts and
interrelated arc interruption takes
place in a vacuum chamber in the
breaker which is called vacuum
interrupter
3000 Amperes
The VCB (Vacuum circuit
breaker) current rating is up to
3000 Amperes. The main
characteristics of vacuum circuit
breaker are, it interrupts the arc in
a vacuum bottle. These can be
applied at up to 35 thousand volts
80. Sulfur hexafluoride circuit
breakers
Sulfur hexafluoride circuit breakers
protect electrical power stations and
distribution systems by interrupting
electric currents, when tripped by a
protective relay. Instead of oil, air, or a
vacuum, a sulfur hexafluoride circuit
breaker uses sulfur hexafluoride (SF6)
gas to cool and quench the arc on
opening a circuit. Advantages over
other media include lower operating
noise and no emission of hot gases,
and relatively low maintenance.
Developed in the 1950s and onward,
SF6 circuit breakers are widely used in
electrical grids at transmission
voltages up to 800 kV, as generator
circuit breakers, and in distribution
systems at voltages up to 35 kV.
81. Georg Simon Ohm
Born16 March 1789
Erlangen, Brandenburg-Bayreuth in
the Holy Roman Empire
(present-day Germany)
Died6 July 1854 (aged 65)
Munich, Kingdom of Bavaria in the
German Confederation
(present-day Germany)
Nationality German Alma mater
University of Erlangen Known for
Ohm's law
Ohm's phase law
Ohm's acoustic law
Awards Copley Medal
(1841)Scientific career Fields
Physics (studies of
electricity)Institutions University of
Munich Doctoral advisor Karl
Christian von Langsdorf
83. A multimeter or a multitester, also known as a VOM (volt-ohm-milliammeter), is an
electronic measuring instrument that combines several measurement functions in one
unit. A typical multimeter can measure voltage, current, and resistance. Analog
multimeters use a microammeter with a moving pointer to display readings.
Study of Multimeter
Measure AC/DC voltage
Measure current
Continuity test
Measure resistance
84. MATERIAL REQUIRED
Multimeter (1000V for AC and 650V for DC) - 1 each
Torque tester (600A) - 1 no.
TOOLS REQUIRED
Cutting pliers - 1 no.
Neon tester - 1 no.
Screwdriver set - 1 no.
PROCEDURE AND OBSERVATION
Task 1: Measuring AC voltage
1. Take multimeter /clip-on-meter and set the switch to AC position
2. Plug the two leads of the meter
3. Measure the voltage between phase & neutral, phase & earth and neutral & earth.
(if any leakage)
85. Task 2: Continuity Test
1. Set the multimeter switch to position
2. Plug the leads if the meter to
3. Check for continuity of a wire, bulb, choke etc. It gives beep sound in case of
continuity.
4. Set the meter switch to position
5. Follow step 2
6. Meter shows the resistance of the particular things
Task 3: Measuring current
1. Unplug the leads of the meter
2. Set the switch to position
3. Hook the clips/ jaws of the meter to any live wire
4. Meter shows the flow of current
SAFETY PRECAUTION
1. Set the meter position and range properly.
2. Do not measure beyond the rated voltage, current etc.
3. Hold / touch the leads properly.
86. An Analog Multimeter
is a device used to
measure limited
electrical quantities such
as Current, Voltage and
Resistance etc.
They have meter
movement mechanism, a
calibrated scale and a
pointer. Reading is
obtained by looking at
the position of the
pointer on the scale.
87. Digital Multimeter is a
device used to measure
multiple electrical quantities
such as Current, Voltage,
Resistance, Capacitance,
Diode values, Transistors
etc.
In a digital multimeter, the
meter movement is replaced
by a digital read out. This
read out is similar to that
used in electronic
calculators.
88. Task 2: Continuity Test
1. Set the multimeter switch to position
2. Plug the leads if the meter to
3. Check for continuity of a wire, bulb, choke etc. It gives beep sound in case of
continuity.
4. Set the meter switch to position
5. Follow step 2
6. Meter shows the resistance of the particular things
Task 3: Measuring current
1. Unplug the leads of the meter
2. Set the switch to position
3. Hook the clips/ jaws of the meter to any live wire
4. Meter shows the flow of current
SAFETY PRECAUTION
1. Set the meter position and range properly.
2. Do not measure beyond the rated voltage, current etc.
3. Hold / touch the leads properly.
89. Using a Multimeter safely is an important technical skill.
The following safety precautions should always be followed:
Never use the ohmmeter section on a live circuit.
Never connect the ammeter section in a parallel with voltage source.
Never overload the ammeter or voltmeter sections by attempting to measure
currents or voltages far in excess of the range switch setting.
Check the meter test leads for broken insulation before working with them.
Avoid touching the bare metal clips or tips of the test probes.
To avoid the danger of accidental shock, disconnect the meter test leads
immediately after the test is completed.
Multimeter – Safety precautions
90. What is Resistor
Resistor is an electrical component
that reduces the electric current. The
resistor's ability to reduce the
current is called resistance and is
measured in units of ohms (symbol:
Ω). If we make an analogy to water
flow through pipes, the resistor is a
thin pipe that reduces the water flow.
A resistor is a passive two-terminal
electrical component that
implements electrical resistance as a
circuit element. In electronic
circuits, resistors are used to reduce
current flow, adjust signal levels, to
divide voltages, bias active elements,
and terminate transmission lines,
among other uses
91. What is Resistance
Resistance is a measure of
the opposition to current
flow in an electrical circuit.
Resistance is measured in
ohms, symbolized by the
Greek letter omega (Ω).
Ohms are named after Georg
Simon Ohm (1784-1854), a
German physicist who
studied the relationship
between voltage, current and
resistance.
Tungsten resistance used in
Incandescent lamp
Nichrome resitance used in
Electrical heater
92. RESISTANCE RESISTOR
Its heat up It doesn’t heat up
In physically it inform of coil In physically it is inform of
solid cylinder
It has no any colour code on it Basically it has no’s of colour
code printed on it
It can’t used in PCB board due
to it heat up
Relevantly its used in all PCB
borad to reduce current
Resistance is the property of a
conductor, which determines
the quantity of current that
passes through it when a
potential difference is applied
across it.
A resistor is an electric
component with a
predetermined electrical
resistance, like 1 ohm, 10
ohms 100 ohms 10000 ohms
etc
Its used for electrical heating
appliances like lamp, heater
,projector etc
Its used in all electronic circuit
i.e computer, mobile , fan
regulator ,speaker woofer to
increase volume etc
94. Resistor Colour code Formula
BB ROY has a Great Britan Very Good Wife
B -Black -head hair
B -Brown
R -Red
O -Orange
Y -Yellow
Great -Green -Indian Flag
Britan -Blue
Very -Voilet
Good -Gray
Wife -White -feet
95. Series Circuits
Two elements in a series
Connected at a single point
No other current-carrying
connections at this point
A series circuit is constructed by
connecting various elements in
series
97. Resistors in series
Analogous formula is true for any number of resistors,
It follows that the equivalent resistance of a series
combination of resistors is greater than any of the
individual resistors
98. Resistors in parallel
Since both R1 and R2 are connected to the same battery, potential
differences across R1 and R2 are the same,
I
I2 I1
R2 R1
V
+
_
I
Req
V
+
_
1 2
1 2
eq
R R
R
R R
1 2
1 1 1
eqR R R
or
99. Resistors in parallel: notes
Analogous formula is true for any number of resistors,
It follows that the equivalent resistance of a parallel
combination of resistors is always less than any of the
individual resistors
100. Comparison between series and parallel:
Series connection Parallel connection
1. Current flows in single path 1.Current flows in several paths
2. Voltage is divided across each
resistance
v = v1 + v2 + v3
2. Voltage is constant
3. Current is constant 3. Current is divided i =i1+i2+i3
4. Total resistance is equal to the sum
of
individual resistance r = r1+ r2+ r3
4. The reciprocal of the total resistance
is
equal to the reciprocal the sum of
individual
resistance i.e. 1/r = 1/r1 + 1/r2+ 1/ r3
5. Fault finding is difficult 5.Fault finding is easy
6.Used for decoration purpose 6. Used for domestic purpose
102. Define Ohm’s law
The current flowing in a conductor is directly
proportional to the applied voltage V and inversely
proportional to its resistance R at temperature being
constant.
• I = V/R
• V = IR
• R = V/I
103. OHM’S LAW
The Ohm‟s Law was propounded by George Simon Ohm,
which defines the relationship between current (i), power (p),
voltage (v) and resistance (r)
I = v / r - 1 r = v / i - 2 v = i x r - 3
Ohm‟s Law states that, in any closed electrical circuit the current
is directly proportional to
voltage applied and universally proportional to the resistance of the
circuit, temperature and
other physical conditions being constant.
104. Solving Problems Using Ohm’s Law Triangle
Example 1: If the resistance of an electric iron is 50Ω and 3.2A
Current flows through the resistance. Find the voltage between
two points.
Ans. If the value of Resistance is asked and the values of the
current and voltage are given, then to calculate resistance
simply cover the R. Now, we are left with the V at the top and
I to the bottom left or V ÷ I.
Given, Resistance (R) = 50Ω
Current (I) = 3.2A
Therefore,
Voltage (V) = I X R = 3.2A x 50 Ω =160V
105. Example 2: An EMF source of 8.0 V is connected to a
purely resistive electrical appliance (a light bulb). An
electric current of 2.0 A flows through it. Consider the
conducting wires to be resistance-free. Calculate the
resistance offered by the electrical appliance.
Ans. If the value of current is asked and the values of the
resistance and voltage are given, then to calculate current
simply cover the I. We are left with Voltage over Resistance or
V ÷ R. So the equation for Current is Voltage divided by
Resistance.
Given,
Voltage (V) = 8.0 V
Current (I) = 2.0 A
Therefore, Resistance (R) = V ÷ I = V/I
= 8/2=4Ω
107. History about Gustav Robert
Kirchhoff
Gustav Robert Kirchhoff, a German physicist, was
born on March 12, 1824, in Konigsberg, Prussia.
His first research topic was on the conduction of
electricity. This research led to Kirchhoff
formulating the Laws of Closed Electric Circuits in
1845. These laws were eventually named after
Kirchhoff and are now known as Kirchhoff’s
Voltage and Current Laws. Since these laws apply
to all electric circuits, understanding their
fundamentals is paramount in the understanding of
how an electronic circuit functions. Although these
laws have immortalised Kirchhoff in the field of
Electrical Engineering, he has additional
discoveries. He was the first person to verify hat an
electrical impulse travelled at the speed of light.
Furthermore, Kirchhoff made a major contribution
to the study of spectroscopy and he advanced the
research into blackbody radiation.
Gustav Robert Kirchhoff
108. There are two types of Kirchhoff's laws , they are:
1.Kirchhoff’s first law or Current Law
2.Kirchhoff’s second law or voltage Law
109. Kirchhoff’s Current Law
In any electrical network the algebraic sum of currents
meeting at a junction is always zero. I = 0
The currents directed towards the junction are taken as positive
while those directed towards away from the junction are taken
as negative
I1 + I2 – I3 – I4 – I5 = 0
I1 + I2 = I3 + I4 + I5
From above expression we can say that the sum of current
flowing towards the junction is equal to the sum of currents leaving
the junction.
110. Kirchhoff’s voltage Law
The algebraic sum of all the potential drops around a closed loop is
equal to the sum of the voltage sources of that loop.
Equation can be given by
V source = V1 + V2 + V3 = I1R1 + I2 R2 + I3 R3
V = IR
i.e. Kirchhoff’s voltage law can be applied only to closed loop. A
closed loop must meet two conditions.
1. It must have one or more voltage sources.
2. It must have a complete path for current flow from any point, around the
loop and back to that point.
111. Magnetic Induction
• Electromagnetic induction is the production of
an electromotive force across a conductor when it is exposed to
a varying magnetic field.
• It is described mathematically by Faraday's law of induction,
named after Michael Faraday who is generally credited with
the discovery of induction in 1831.
• Electromagnetic induction was discovered independently
by Michael Faraday in 1831 and Joseph Henry in 1832.
112. FIRST LAW : Whenever there is a change in the magnetic flux linked
with a circuit an e.m.f and consequently a current is induced in the
circuit. However, it lasts only so long as the magnetic flux is changing.
(or)
Whenever a conductor cuts magnetic flux, an e.m.f is induced in that
conductor.
SECOND LAW: It states that the magnitude of the induced e.m.f is
equal to the rate of change of flux linkage.
FARADAY’S LAWS OF ELECTRO-
MAGNETIC INDUCTION
113.
114. State Lenz’s Law
Lenz’s law states that the direction
of the current induced in a
conductor by a changing magnetic
field is such that the magnetic field
created by the induced current
opposes the initial changing
magnetic field which produced it.
Lenz’s Law is named after the
German scientist H. F. E. Lenz in
1834. Lenz’s law obeys Newton’s
third law of motion (i.e to every
action there is always an equal and
opposite reaction) and the
conservation of energy (i.e energy
may neither be created nor
destroyed and therefore the sum of
all the energies in the system is a
constant).
115. Lenz’s law
The direction of the current is found by using this law which
was formulated by Lenz in 1835.
This law states that electro-magnetically induced
current always flows in such direction that the action of the
magnetic field set up by it tends to oppose the very cause
which produces it.
117. A relay is an electrical switch that opens and closes
under control of another electrical circuit.
So relay is a switch which controls (open and close)
circuits electromechanically. The main operation of this
device is to make or break contact with the help of a signal
without any human involvement in order to switch it ON
or OFF. It is mainly used to control a high powered circuit
using a low power signal.
Relay
118. •Generally relay is having following terminals and contacts.
• Input Coil: Operating voltage for relay is feeded to it.
• Normally closed (NC) Contact: It disconnect the circuit
when the relay is activated.
• Normally Open Contact (NO): It connects the circuit
when the relay is activated.
• Pole: It is the common terminal between NC and NO.
119. Types of Relay
EFR Relay [ Earth fault relay ]
OCR Relay [ Over current Relay ]
OLR Relay [ Over load Relay ]
121. Introduction
Now a days AC system, Specially 3 phase (poly phase)
system is most commonly adopted for generation,
transmission and distribution, because it is economical
and efficient. In India all generating stations and
alternators are practically producing 11 KV/ 21 KV.
Using the AC system, such power can be stepped up,
transmitted and distributed to reach the consumers‟ point,
keeping low cost and reduced size of conductor in
mind. A transformer is a device which conveys power
from the generating station to the consumers‟ point.
122. Define Transformer
The transformer may be defined as a static piece of
electrical apparatus which converts electrical power
from one circuit to another at the same frequency
while changing the corresponding values of current and
voltage.
OR
Transformer is a static device which transfer the voltage
from one circuit to another circuit but without changing
the frequency is called Transformer
123. Working Principle
The transformer works on the principle of Mutual
Induction.
OR
Transformer works on the principal of Farday’s law of
electromagnetic induction
124. Classification of Transformers
1. According to the magnetic core
a. Core type
b. Shell type
c. Berry type
2. According to the voltage
a. Step up transformers
b. Step down transformers
3. According to the phases / winding
a. Single phase transformer
b. Three phase transformer
4. According to the power / usage
a. Lighting / distribution transformer
b. Power transformer
125. 5. According to cooling
a. Self cooled
b. Air force cooled
c. Oil self cooled
d. Forcibly oil cooled
6. According to the location
a. Indoor transformer
b. Outdoor transformer
7. According to the output:
a. Auto transformer
b. Instrument transformer
127. For an Ideal transformer the voltage ratio is equal to the turns ratio
and power in equals to the power out. It means
V2/ V1=N2/ N1=I1/I2
Where,
V2 = Secondary voltage
V1 = Primary voltage
N2 = No. of turns in secondary coil
N1 = No. of turns in primary coil
I2 = Secondary Current
I1 = Primary Current
128. Basic Parts of a Transformer
These are the basic components of a transformer.
Laminated core
Windings
Insulating materials
Transformer oil
Tap changer
Oil Conservator
Breather
Cooling tubes
Buchholz Relay
Explosion vent
129. Function of Silica Gel Breather
Most of the power generation companies use silica gel breathers
fitted to the conservator of oil filled transformers. The purpose of
these silica gel breathers is to absorb the moisture in the air
sucked in by the transformer during the breathing process.
What is Transformer Breathing?
When load on transformer increases or when the transformer
under full load, the insulating oil of the transformer gets heated
up, expands and gets expel out in to the conservator tank present
at the top of the power transformer and subsequently pushes the
dry air out of the conservator tank through the silica gel breather.
This process is called breathing out of the transformer.
When the oil cools down, air from the atmosphere is drawn in to
the transformer. This is called breathing in of the transformer.
130. Use of Silica gel breather
During the breathing process, the incoming
air may consist of moisture and dirt which
should be removed in order to prevent any
damage. Hence the air is made to pass
through the silica gel breather, which will
absorb the moisture in the air and ensures
that only dry air enters in to the
transformer. Silica gel in the breather will
be blue when installed and they turn to pink
colour when they absorb moisture which
indicates the crystals should be replaced.
These breathers also have an oil cup fitted
with, so that the dust particles get settled in
the cup.
Thus Silica gel breathers provide an
economic and efficient means of
controlling the level of moisture entering
the conservator tank during the breathing
process.
131. OLTC
OLTC stands for On Load Tap Changer, which
is a device used for selecting different taps to
make fine adjustments in the output voltage,
without disconnecting the load. It is oil trip
circuit breaker. which will cut-off the
Transformer when the oil in the transformer
is degenerated due to continuous heating.
132. RTCC
REMOTE TAP CHANGER CONTROL PANEL RTCC is
“Remote Tap Changer Control “which is a Programmable
device to control the output of the transformer through
OLTC unit fitted in the transformer through control cables