Because of the properties of sf6 gas such as excellent arc quenching, high electronegative nature, and excellent. Why sf6 is used in circuit breakers instead of co2. Jan 02, 2019 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. The aim has been to provide an uptodate analysis of the theoretical and practical problems involved in circuit breaker design. By means of the special spring catches, hook the ropes to the circuitbreaker hook to the special anchoring points provided in the structure and lift. The gas also interrupts the current flow when the contacts are open. Some of the advantages of sf6 circuit breakers, their. Sf 6 gas has excellent insulating property and it has a high electronegativity. Using the circuit breaker coordination information, set the dials of the micro powershield to the desired threshold pickup and time delay.
Sf6 circuit breaker types and operation of sf6 circuit. Circuit breaker performance and sf6 density monitor con gno no com no no nc com. A disconnecting circuit breaker is a combination of a disconnector and a circuit breaker, which fulfill all requirements for a circuit breaker as well as for a disconnector. Circuit breaker cb has been around for almost as long as industrial electrical power usage. Circuit breaker for rating 145kv shall be suitable for gang operated three phase auto reclosing. The circuit breaker should remain in this discon nected position until system checkouts have been completed. The sf6 dead tank circuit breakers assure a high level of. Unlike a fuse, which operates once and then must be replaced, a circuit breaker can be reset either manually or automatically to resume. Sulpher hexafluoride or sf 6 circuit breaker is most popular and widely used breaker. If a circuit breaker has a straight voltage rating, such as 240 volts, it can be used in an ac system where the voltage between any two conductors is not greater than the single voltage rating of the circuit breaker.
Pdf on jan 1, 2002, lukas zehnder and others published sf6 generator circuit breaker system for shortcircuit currents up to 200 ka find, read and cite all the research you need on researchgate. Abb library is a web tool for searching for documents related to abb. Purpose share status on replacement of sf6 with environmentally friendly insulating gas for high voltage gis and breakers. Services for abb medium voltage equipment hpa iec sf6 mechanical circuit breaker hpa is the family name of abb medium voltage equipment that are no longer in active phase and are managed by abb service according to the abb life cycle management policy and services.
The circuitbreaker is made up of three separate poles. A circuit breaker is an automatically operated electrical switch designed to protect an electrical circuit from damage caused by excess current from an overload or short circuit. This circuit breaker range meets iec standard 62271100. Download as ppt, pdf, txt or read online from scribd. Combined is a disconnecting circuit breaker based on the ltb or the hpl circuit breaker. Abb high voltage service us started offering sf 6 gas.
In sulpher hexafluoride or sf6 circuit breaker, sulpher hexafluoride sf 6 gas is used as an insulating and arc quenching medium. They are very reliable and require less maintenance than air blast or oil breakers and. Phase segregated type 6 gas insulated switchgear type. Sf6 has a number of advantages for use as an insulator. Actuator lever used to manually trip and reset the circuit breaker. Lf circuit breakers use the sf6 gas self expansion technique. Cgl is the only manufacturer in india for supply of 420kv sf 6 circuit breakers to meet the high altitude requirement of 1600m. Both compact and dependable, it is ideally suited to the most demanding applications. View and download abb sf6 installation and maintenance instructions manual online.
Also indicates the status of the circuit breaker on or offtripped. Abb library is a web tool for searching for documents related. The sf 6 gas circuit breaker gcb products range is as follow. Rmag dead tank vacuum magnetic circuit breaker, instruction manual 15. A brief history of the use of sf6 in switchgear is given. The experiments are performed with a puffertype breaker model in a medium voltage 10 kv lab circuit. Merlin gerin offers an sf6 circuit breaker, the fluarc fb. Set the thresholds and time delays of the solid state trip system. Sf6 circuit breaker advantages disadvantages applications. In the last article the working of a vacuum circuit breaker was illustrated. Co fuji electric as a manufacturer of comprehensive substation equipment is ready to supply advanced sf6 gas insulated switchgear gis superior in. Feb 28, 2018 sf6 circuit breaker working principle rachel power system.
This type of breaker is mostly used for ehv systems like 220 kv, 400 kv and 765 kv. High temperature sf6 gas and ptfe vapour both contain a significant proportion of. This paper gives a short survey of the origins for current chopping in high voltage networks and describes an investigation of current chopping in sf 6. When equipped with an electrical operating mechanism, the circuit breaker can take on remote control functions and implement reclosing cycles. For circuit breaker with sf6 gas, a temperature compensated gas density monitor with gas pressure gauge and pressure switch shall be provided at a convenient place to indicate sf6 gas density and gas pressure. Vacuum circuit breaker and ocb oil circuit breaker. Ohb medium voltage circuitbreakers for outdoor installation use sulphur hexafluoride gas sf6 to extinguish the electric arc and as the. Outdoor live tank sf circuit breaker type ohb for 2436. The general properties of sf6 gas and its sf6 byproducts are presented. The terminal box, fixed on the upper protection, is available for connection of the circuit breaker auxiliary circuits.
Circuit breakers to meet the high altitude requirement of 1600m. Therefore, nowadays sf6 circuit breaker and the vacuum circuit breaker is preferred in h. Due to high electronegativity, it has a high affinity for absorbing free electrons. Iec indoor sf6 gas circuit breaker hd4 superior performance for smooth protection hd4 breakers are used in electrical distribution for control and protection of cables, overhead lines, transformer and distribution substations, motors, transformers, generators and capacitor banks. More than 9000 crompton greaves sf6 gas circuit breakers upto 420 kv for outdoor application have been put into service. Medium voltage circuit breaker arc extinguishing method.
Fixed circuit breaker the fixed circuit breaker see fig. The circuit breaker poles contain sf6 at a pressure of 380 kpa for 36kv application and 550kpa for 40. What is air circuit breaker acb in electrical system in hindi duration. 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. Pdf sf6 generator circuit breaker system for short. Sf6 ate 36 kv 2500 a 25 ka sf6 circuit breaker up to 36 kv 2500 a 25 ka. It has a proven design and long performance in a vast range of environments and ambient conditions with an installed base in over 80 countries. Well proven circuit breaker based on modular design, factory assembled and tested for rapid installations. The air blast circuit breakers are very sensitive, to the variations in the rate of rise of restriking voltage. Abb offers a complete sf 6 gas management solution, in an efficient and environmentally friendly manner, from installation to decommissioning. This circuit breaker in a grounded tank called a dead tank, could interrupt 41.
Be sure the circuit breaker and its mechanism are disconnected from all electric power, both high voltage and control voltage, before it is inspected or repaired. More than 100,000 circuit breakers with selfblast interrupters and springspring operated mechanism have been in service since 1989 including more than 25,000 dead tank circuit breakers. With the largest installed base of high voltage circuit breakers in north america, abb is widely known for its switchgear expertise. Diflu is a threephase circuit breaker that uses sf6 dual flow puffer. Sf 6 circuit breakers operate to switch electric circuits and equipment in and out of the system. A balance of lecture and handson activities are utilized to emphasize operating characteristics and maintenance and testing requirements. Current chopping can be minimized using sf6 at low pressure and velocity. The first research into industrial applications was done by the general electric company in 1937 when they realized that the gas could be used for insulation in electrical equipment. Using sf analysis for condition based maintenance 6 of. Oil circuit breakers and air circuit breakers have been gradually replaced by sf6 circuit breakers. Sulfur hexafluoride circuit breakers protect electrical power stations and distribution systems by interrupting electric currents, when tripped by a protective relay. After the circuit breaker has been disconnected from the. A comparative study of arc behavior in an autoexpansion circuit. Maintenance is required for compressor plant which.
The hd4lmt medium voltage circuit breaker consists of three separate sf6 circuit breaker poles, that are maintenance free lifelong sealed pressure units complying with. Designers need to have an understanding of the parameters of power systems in which circuit breakers have a duty. Installationmaintenance instructions mb lowvoltage. The edf sk is a live tank sf 6 autopuffer tm circuit breaker. Advantages over other media include lower operating noise and no emission. Sf6 training and certification since the fluorinated greenhouse gas regulations were revised in 2014, if you carry out any activities that directly involve the recovery or handling of sf 6 from high voltage hv switchgear, then you need to have passed a theoretical and practical examination in sf 6 handling and hold a certificate of competence.
In 1939 thomsonhouston patented the principle of using sf 6 for insulating cables and capacitors. Sf6 circuit breaker working principle rachel power system. 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. 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. Fixed circuitbreaker the fixed circuitbreaker see fig. The oil circuit breakers, air circuit breakers and low oil circuit breakers are becoming outdated now. Circuit breakers present very special design problems because of the wide mixture of experience required. A number of units are connected in series according to the system voltage.
Iec outdoor gas insulated sf6 circuit breaker ohb medium voltage circuit breaker with mechanical operating mechanism designed for distribution systems up to 40. Circuit breakers, gas, outdoor type new, used, or reconditioned. Also go through disadvantage so that you may know the safety precautions too. Mar 28, 2017 sf6 circuit breaker working principle duration. Applications a typical sf6 circuit breaker consists of interrupter units each capable of dealing with currents upto 60 ka and voltages in the range of 5080 kv. Advantages of sf6 due to high arc quenching property of sf6, arcing time is less which leads to low contact erosion. Aug 31, 2017 sf6 gas has its advantages and disadvantages. Medium voltage products hd4 installation and service. Nov 24, 2016 applications a typical sf6 circuit breaker consists of interrupter units each capable of dealing with currents upto 60 ka and voltages in the range of 5080 kv. The breakers have a smaller footprint, so they use less real estate which can be very expensive. Seminar on sf6 circuit breaker under the guidance of.
By means of the special spring catches, hook the ropes to the circuitbreaker. Principal electrical engineer tennessee valley authority senior member, ieee. You may make this as a reference, taking into consideration your own requirements. The circuitbreaker poles contain sf6 at a pressure of 380 kpa for 36kv application and 550kpa for 40. Iec indoor sf6 mv circuit breaker for primary distribution. I have listed below few advantages which make sf6 desirable for being used in cb. A disconnecting circuitbreaker is a combination of a disconnector and a circuitbreaker, which fulfill all requirements for a circuitbreaker as well as for a disconnector.
Combined is a disconnecting circuitbreaker based on the ltb or the hpl circuitbreaker. Sf1 circuit breakers fixed version from 12 kv to 36 kv sf2 circuit breakers fixed version from 24 kv to 40. Sf 6 gas has many superior properties which makes it perfect for arc quenching. Medium voltage products hd4 installation and service instructions. As with highvoltage circuit breakers, mediumvoltage switchgear requires little maintenance and are particularly suitable for locations where oilfilled equipment is. We can divide an sf6 circuit breaker into two units, namely. Sf6 properties, and use in mv and hv switchgear studiecd. The terminal box, fixed on the upper protection, is available for. Rated shortcircuit breaking current of circuit breaker ka 31.
Its basic function is to interrupt current flow after a fault is detected. At this point we are aware that the medium in which arc extinction of the circuit breaker takes place greatly influences the important characteristics and life of the circuit breaker. Sf6 circuit breakers have been developed for voltages 115 kv to 230 kv, power ratings 10 mva to 20 mva and. Apr 24, 2018 in sulpher hexafluoride or sf6 circuit breaker, sulpher hexafluoride sf 6 gas is used as an insulating and arc quenching medium. Take note that this sample has bushing current transformers bct on it. Based on the r e sults and analysis carried out, the sf6 breaker ha s the highest pe rformance.
The sf6 gas circuit breaker gcb products range is as follow. 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. By means of the special spring catches, hook the ropes to the circuit breaker. 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. Arcing time is very less thereby less burning of contacts disadvantages advantages radialblast type 1. Difference between circuit breaker and disconnectorisolator. Elden in 1898 installed at the boston electric light company l street plant later boston edison open tank with upward motion operation. They react automatically to fluctuations in electrical current, and trip to protect a circuit from damage from overloading or short circuiting. Hi friends, in this article, i am describing the sf6 circuit breaker construction and working principle. An arc quenching for a default current of 50 ka, 245. Service mv it abb medium voltage equipment hpa service. Exhaust the pressure from air receiver of any compressed air circuit breaker before it is inspected or re paired. Abb library is a web tool for searching for documents related to abb products and services.
The dielectric strength of sf6 increases with pressure so smaller breakers can be used at higher voltages. Below is an example of specifications of a power circuit breaker, using sf6 as its arc quenching medium. Iec live tank sf6 mechanical circuit breaker rmerge obsolete iec live tank sf6 mechanical circuit breaker sfe. In the oil circuit breakers, air circuit breakers and low oil circuit breakers, arc extinction take place slowly after the moment of contact separation. Hence, the arc is usually extinguished after a few half cycles of current have passed. The anchoring holes are drilled in the lower part of the frame. These circuit breakers are filled with compressed sulfurhexafluoride gas which acts to open and close the switch contacts. This performance was already significant, but the three chambers per pole and the highpressure source needed for the blast 1. A circuit breaker in which sf6 under pressure gas is used to extinguish the arc is called sf6 circuit breaker. 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.