A circuit breaker is an automatically-operated electrical switch designed to protect an electrical circuit from damage caused by overload or short circuit.
Its basic function is to detect a fault condition and, by interrupting continuity, to immediately discontinue electrical flow.
A circuit breaker is an automatically-operated electrical switch designed to protect an electrical circuit from damage caused by overload or short circuit.
Its basic function is to detect a fault condition and, by interrupting continuity, to immediately discontinue electrical flow.
i have complited the summer training from Bihar State Power Transmission Company LTD.where i learned a lots of thing about the Grid Substation and Various Type Of Component ,which is used in the Grid sub-station.
i have complited the summer training from Bihar State Power Transmission Company LTD.where i learned a lots of thing about the Grid Substation and Various Type Of Component ,which is used in the Grid sub-station.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
2. CONTENTS
Introduction
Circuit Breaker
Components of circuit breaker
Working Principle
Arc Formation
Methods of Arc quenching
Types of Circuit Breakers
Conclusion
2
3. INTRODUCTION
Nowadays, the modern power system deals with huge
power network and huge numbers of associated
electrical equipment.
During short circuit fault or any other types of electrical
fault these equipment suffer a high stress of fault current
which may damage the equipment and networks.
For saving these equipments and the power networks,
the fault current should be cleared from the system as
quickly as possible.
These complications have paved the way for the
evolution of circuit breakers.
3
4. CIRCUIT BREAKER
A circuit breaker is an electromechanical switch that breaks
the circuit either manually or automatically under all
conditions at no load, full load or short circuit.
Unlike a fuse, which operates once and then must be
replaced, a circuit breaker can be reset (either manually or
automatically) to resume normal operation.
Its basic function is to detect a fault condition, by interrupting
continuity and immediately discontinue the electrical flow.
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6. WORKING PRINCIPLE
The circuit breaker mainly consists of fixed contacts and moving
contacts.
In normal ON condition of circuit breaker, these two contacts are
physically connected to each other due to applied mechanical
pressure on the moving contacts.
The potential energy can be stored in the circuit breaker by
different ways like by deforming metal spring, by compressed
air, or by hydraulic pressure.
During fault condition, potential energy must be released.
Release of potential energy makes sliding of the moving contact
at extremely fast manner and breaks the circuit.
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7. ARC FORMATION
During the separation of contacts, due to large fault current and
high current density at the contact region, the surrounding
medium is ionized. Thus an electric arc is formed.
Factors responsible for arc are:
Potential difference between the contacts
Ionized particles between the contacts.
MOVING CONTACT
FIXED CONTACT ARC
7
8. METHODS OF ARC
QUENCHING
High Resistance Method:
Arc resistance is made to increase with time so that
current is reduced to a value insufficient to maintain the arc.
Low Resistance Method:
Dielectric Medium between the contacts is built up more
rapidly so that the arc fails to restrike and the current will be
interrupted.
Arc Resistance depends on factors like:
Degree of Ionization
Length of the arc
Cross section of arc
8
10. OIL CIRCUIT BREAKERS
These are the oldest type circuit breakers.
It can be operated 11kV - 765kV.
Oil is used as arc quenching media as well
as insulating media between current
carrying contacts and earthed parts of
the breaker.
These are of two types:
BOCB (Bulk oil Circuit Breaker)
MOCB (Minimum oil Circuit Breaker)
The oil used here is same as transformer
insulating oil.
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11. VACUUM CIRCUIT
BREAKERS
It is operated at medium voltage range
(3.3 - 33kV).
The arc quenching takes place in vacuum.
A vacuum interrupter is a switch which
uses electrical contacts in a vacuum for the
process of quenching the arc.
The vacuum pressure inside a vacuum
interrupter is normally maintained at 10-6 bar.
The technology is suitable for mainly
medium voltage application. For higher voltage
vacuum technology has been developed but not
commercially viable.
11
12. AIR BLAST CIRCUIT
BREAKERS
It operates using high velocity blast
of air which quenches the arc.
The contacts are opened in a flow
of air blast and quenches the arc.
This rapidly increases the dielectric
strength of the medium between
contacts and prevents from arc.
Then the arc is extinguished and
flow of current is interrupted.
12
13. SF6 CIRCUIT BREAKERS
It uses Sulphur Hexafluoride (SF6) gas
as an arc quenching medium.
In closed position, SF6 gas pressure -
2.8 kg/cm2
In opened position SF6 gas pressure-
14 kg/cm2
SF6 is released from a valve and
rapidly absorbs the free electrons in
the arc path to form immobile negative
ions to build up high dielectric strength
and extinguishes it.
After operation the valve is closed by
the action of a set of deformed springs.
13
14. CONCLUSION
Circuit breaker is the most essential part of the electrical
networks as it protects every device from damage.
By using appropriate circuit breaker for appropriate
operating voltages we can provide protection for bus bar
and electrical equipments like Power transformers,
generators, C.T, P.T, etc. from different faults that occur in
power system.
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