The circuit breaker can make or break the circuit either manually or by remote control. Diflu is a threephase circuit breaker that uses sf6 dual flow puffer. Sulfur hexaflouride sf6 is an electronegative gas and has a strong tendency to absorb free electrons. Handling and use of sulfur hexafluoride gas page 4 of 8 v. Identifying, quantifying and controlling emissions of. A circuit breaker in which sf 6 under pressure gas is used to extinguish the arc is called sf 6 circuit breaker. In addition to its many advantages in terms of technical properties, sf 6 has the disadvantage of having a very high global warming potential gwp. As sf 6 is heavier than air it displaces the oxygen in the air if it is inadvertently set free.
If moisture is able to infiltrate over time, arcing can occur. Circuit breaker adjusted distribution rate description circuit breaker distribution rate adjustments are made based on the circuit breaker credits reported in section 5 columns 2, 3, and 4 of the abstract. It combines the effect of thermal expansion with a rotating arc to create arc. Hence, this gas also began to be used in circuit breaker as arc quenching medium. Sf6 is a very good dielectric material which can resist high potentials. Due to high electronegativity, it has a high affinity for absorbing free electrons. Sulfur hexafluoride 100 2551624 ingredient name % cas number there are no additional ingredients present which, within the current knowledge of the supplier and in the. The dielectric and other physical and chemical properties related to its lack of reactivity have led to the extensive use of sf 6 as an insulating medium in switching equipment e. Pdf electrical strength analysis of sf6 gas circuit breaker element.
Medium voltage mv is defined as 1kv to 36kv high voltage hv is defined as 36kv to 2kv. Application, advantages and disadvantages of all types of. Measurement of water vapor in sulphur hexafluoride, sf6. Sulphur hexafluoride is a greenhouse gas, and wilful venting to the atmosphere is illegal refer to section 9. Worlds first sf 6 gas insulated substation was established in paris in the year of 1966. Performance analysis of high voltage sf6 circuit breaker based on coupling computation of electricgas flow field. Each table includes the organizationauthor, title, date, and topics addressed for each. Gasco sulfur hexafluoride calibration gas 100 ppm balance air in a 600 liter aluminum disposable cylinder cga 590 connection.
The paper also provides the recommendations for change sf6 circuit breaker. Sf6 emissions reduction partnership exelon has participated in the sf6 emissions reduction partnership with u. Fist 59, management and safe handling procedures for sulfur hexafluoride sf6 gas 5. Sf6 circuit breakers construction, types and working. Sulphur hexa fluoride sf6 extra high voltage circuit.
Handling of sulfur hexafluoride gas central facilities. Solvays sulphur hexafluoride is a non toxic, inert, insulating. Additionally, it is used for the filling of insulated windows and for the casting of magnesium. Sulphur hexafluoride sf6 circuit breaker a circuit breaker in which sf 6 under pressure gas is used to extinguish the arc is called sf 6 circuit breaker. Test conducted at ornl indicate that vacuum conditions, as might be found in sfsub 6 circuit breakers prior to filling with sfsub 6, could lead to significant changes in calibration, resulting in erroneous readings. A circuit breaker is a protective device which can break the circuit automatically under the fault condition. Sf6 circuit breaker sulfur hexafluoride circuit breaker. It is a nontoxic, colourless and odourless inert gas. The reason for the exemption, writes nicholas ottersbach, researcher, that there was no viable alternative. Circuit breaker a 2 pole miniature circuit breaker from wikipedia, the free encyclopedia a circuit breaker is an automaticallyoperated electrical switch designed to protect an electrical circuit from damage caused by overload or short circuit. Instead of oil, air, or a vacuum, a sulfur hexafluoride circuit breaker uses sulfur hexafluoride gas to cool and quench the arc on opening a circuit. Sulphur hexafluoride article about sulphur hexafluoride. The circuit breaker credit amount is the amount the net tax bill on each type of property exceeds the property tax cap.
A circuit breaker in which sulphur hexafluoride gas or sf 6 gas is used as the arc quinching medium, known as an sf6 circuit breaker. In an sf6 circuit breaker, sulphur hexafluoride gas is used as the arc quenching medium the sulphur hexafluoride gas sf6 is an electronegative gas and has a strong tendency to absorb free electrons. Use and handling of sulphur hexafluoride sf6 in high voltage switchgear and controlgear. Sulphur hexafluoride, sf6, is a nontoxic, inert, insulating and cooling gas of high dielectric strength and thermal stability. Why do the sf 6 gases have an excellent heat transfer property. Typical 245 kv dead tank circuit breakers using sf6 gas as. A circuit breaker in which the current carrying contacts operate in sulfur hexafluoride or sf6 gas is known as sf6 circuit breaker. It therefore warrants methodical and careful handling. The excellent dielectric properties of sf6 gas helped in.
Typical for a nonpolar gas, it is poorly soluble in water but quite soluble in nonpolar. In electrical energy technologies, the gas sulphur hexafluoride sf 6 currently plays a key role as an insulating and arcquenching medium, particularly in switchgear. The oil is both acts as an arc extinguishing medium and as an insulator between the live part and earth. This document provides the technical procedures for the analysis of sulfur hexafluoride sf. The contacts of the breaker are opened in a highpressure flow sulphur hexafluoride sf6 gas and an arc is struck between them. An air circuit breaker for low voltage less than volts power distribution switchgear. Hv circuit breaker type generator circuit breaker fkga8 generator circuit breaker i sc 210 ka u r 33 kv sf 6 circuit breaker designed for power plants from 700 to 1,500 mw it is equipped with a springoperated mechanism per pole. Instead of oil, air, or a vacuum, a sulfur hexafluoride circuit breaker uses sulfur hexafluoride sf 6 gas to cool and quench the arc on opening a circuit. This technique is the result of many years experience in sf6 technology and major research work. All sf 6 gas shall be obtained through a central facility.
Sf6 properties, and use in mv and hv switchgear contents 1 introduction 1. Gas circuit breaker gcb uses sulphurhexafluoride sf6 gas to quench the arc because of its high dielectric strength, unique arc quenching ability, excellent thermal stability and good thermal. In case of air blast and oil circuit breakers, the extinguishing force builds up relatively slowly after the moment of contact separation and hence the arc is usually extinguished after a few cycles of. Comed and peco have approximately 200,000 lbs of sf6 in service within twopressure breakers, puffer breakers, circuit switchers, and gas insulating. This can lead to premature failure of the breaker, possibly with catastrophic results. Gasco sulfur hexafluoride calibration gas 100 ppm balance nitrogen in a 103 liter steel disposable cylinder. A circuit breaker in which the current carrying contacts operate in sulphur hexafluoride or sf6 gas is known as an sf6 circuit breaker. The designated central facility is responsible for maintaining a log. Type medium voltage, breaking capacity 1 air break circuit. Sf6 gas is used as the arc quenching medium sulfur hexafluoride sf6 is an electronegative gas and has a strong tendency to absorb free electrons. Application, advantages and disadvantages of oil, minimum oil, air blast, sulfur hexafluoride, vacuum circuit breaker. A circuit breaker in which uses sulfur hexafluoride or sf6 gas as arc extinguished medium is known as sf6 circuit breaker. Circuit breakers, sulphur hexafluoride sf6 circuit breakers, air break south korea. Abb library is a web tool for searching for documents related to abb products and services.
Sulfur hexafluoride sf6 recovery generon pioneering. Specification of technical grade sulphur hexafluoride sf6 for use in electrical equipment purposes legally binding document step out from the old to the newjawaharlal nehru invent a new india using knowledgesatyanarayan gangaram pitroda. It is chemically inert, gaseous even at low temperature, non flammable, non toxic, non corrosive. Sf 6 gas has excellent insulating property and it has a high electronegativity. Due to its high dielectric strength, it is particularly suited for application in high power circuit breakers as well as in highvoltage cables, transformers, and switchgears. Catalog of guidelines and standards for the handling and. The mechanical operating mechanism used is esh type with stored energy and free release which allows. Outdoor sf6 circuit breaker type ohb instruction for storage, installation, service and maintenance. In particular, it prohibits the import, sale and use of new products containing fluorinated gases after 1 january 2006 and prohibits the. Sf6 circuit breaker advantages disadvantages applications. Sf 6 is expensive and is also a powerful green house gas 20,000 times more potent than co 2. Sulfur hexafluoride sf 6 is an inorganic, colorless, odorless, nonflammable, nontoxic but extremely potent greenhouse gas, and an excellent electrical insulator. The comparison of arcextinguishing capability of sulfur.
Authors bureau of reclamation hydroelectric research and technical services group denver, colorado 7. Sulfur hexafluoride sf6 recycling program for out of. Measurements at ornl were made on the kahn moisture sensor which doble engineering wants to evaluate for use in sfsub 6 circuit breakers. Concept for sf6free transmission and distribution of. Sulphur hexafluoride sf6 is used as a switchgear interrupting medium from 1 to 800kv nonflammable arcquenching nontoxic. Circuit breaker dielectric strength current zero pure carbon dioxide priming. Performing organizations names and addresses bureau of reclamation denver federal center po box 25007 denver co 802250007 8. Sf6, the most potent greenhouse gas in existence, was banned for all applications in the eu in 2014 except in the electricity industry. But according to ottersbach that is no longer the case. Sf6 gas is used as an insulating medium in high kva breakers. Advantages over other media include lower operating noise and no. It consists of current carrying contacts enclosed in a strong, weathertight earth metal tank and the tank is filled with transformer oil.
Sf6 puffer type circuit breaker development work on circuit breakers using sulphur hexafluoride sf6 gas started in the 1950s and a few initial designs were made in early 1960s. Sf 6 has an octahedral geometry, consisting of six fluorine atoms attached to a central sulfur atom. Sulphur hexafluoride medium voltage circuit breakers launched into market from 1971. Sulfur hexafluoride circuit breakers protect electrical power stations and distribution systems by interrupting electric currents, when tripped by a protective relay. During short circuit fault or any other types of electrical fault these.
Sf6 is an inert gas, but decomposed components as a result of electrical arcing or naked flames are toxic and hazardous. Its density is 5 times that of air and heat convection is. Since the 1980s, sulfur hexafluoride sf6 has been used extensively in the electricity transmission and distribution industry as an insulator and arc interrupter for high and medium voltage circuit breakers, switchgear and other electrical equipment. Sf 6 circuit breakers are made from 72550kv with interruption current of 20 to 63 ka and rated current of 1,200 to 12000 amps because of the properties of sf 6 gas such as excellent arc quenching, high electronegative nature, and excellent dielectric strength sf 6 circuit breakers are popular for high voltage applications and above.
Sf 6 sulphur hexafluoride gas has excellent dielectric, arc quenching, chemical and other physical properties which have proved its superiority over other arc quenching mediums such as oil or air. Electrical breakdown of long gaps in sulfur hexafluoride. Sulfur hexafluoride sf 6 is a relatively nontoxic gas used in a number of applications for its inert qualities. Unlike a fuse, which operates once and then has to be replaced, a circuit breaker can be reset either manually or. The authorisation thus given to the federal ministry of agriculture, forestry, environment and water management concerns prohibitions and restrictions affecting partially fluorinated and perfluorinated hydrocarbons and sulphur hexafluoride. Sulphur hexafluoride sf 6 is an excellent dielectric gas for high voltage applications.