What is the purpose of compressed air in SF6 breaker?

1 Answer

Answer :

This used for drive for opening and closing of the contacts. (Arc quenching is taken care by SF6 gas) 

Related questions

Description : For interrupting capacitive currents which Circuit Breaker (CB) is used a) SF6 CB b) Oil CB c) Vacuum CB d) Air blast CB

Last Answer : Ans: Vacuum CB

Description : What Is Sf6 Circuit Breaker?

Last Answer : SF6 is Sulpher hexa Flouride gas.. if this gas is used as arc quenching medium in a Circuitbreaker me SF6 CB.

Description : What are the levels of SF6 gas in 220 kV breaker and their significance?

Last Answer : 7 kg/cm2 - normal pressure 5.2 bar - alarm 5.0 bar - closing/tripping operation blocked. 

Description : Which of the listed precautions should be taken when cleaning the internals of a motor with compressed air? A. Open the machine on both ends so as to allow the air and dust to escape. B. Be certain that the ... panel. C. Be certain that the air is clean and as dry as possible. D. All of the above.

Last Answer : Answer: D

Description : Which of the following circuit breakers has high reliability and minimum maintenance ? (a) Air blast circuit breakers (b) Circuit breaker with SF6 gas (c) Vacuum circuit breakers (d) Oil circuit breakers

Last Answer : (b) Circuit breaker with SF6 gas

Description : Which of the following medium is employed for extinction of arc in air circuit breaker ? (a) Water (b) Oil (c) Air (d) SF6

Last Answer : (c) Air

Description : Describe the construction of SF6 circuit breaker with neat diagram.

Last Answer : Construction of SF6 Circuit Breaker : A sulphur hexafluoride (SF6) circuit breaker consists of fixed and moving contacts enclosed in a chamber. The chamber is called arc interruption ... contact, moving contact and arcing horn are coated with a copper-tungsten arc-resistant material. 

Description : Explain construction and working of SF6 circuit breaker.

Last Answer : Construction: A sulphur hexafluoride (SF6) circuit breaker consists of fixed and moving contacts enclosed in a chamber. The chamber is called arc interruption chamber, which contains the ... arc being extinguished. Finally the gas enters the contact space increasing the dielectric strength.

Description : what is SF6 circuit breaker?

Last Answer : SF6 is Sulpher hexa Fluoride gas. If this gas is used as arc quenching medium in a Circuit breaker means SF6 CB.

Description : What are the characteristic of SF6 gas?

Last Answer : It has good dielectric strength and excellent arc quenching property. It is inert, non-toxic, noninflammable and heavy. At atmospheric pressure, its dielectric strength is 2.5 times that of air. At three times atmospheric pressure, its dielectric strength is equal to that of the transformer oil.

Description : What is meant by electro negativity of SF6 gas?

Last Answer : SF6 has high affinity for electrons. When a free electron comes and collides with a neutral gas molecule, the electron is absorbed by the neutral gas molecule and negative ion is formed. This is called as electro negativity of SF6 gas.

Description : What are the properties of SF6 gas?  

Last Answer : This is inert gas. Odorless, non-toxic, colourless, stable, non-inflammable and density is more hence high dielectric strength. The special property of this gas is Electro negativity. This gas ... more slow in conduction, so that resistance in medium is increases and get arc get extinguishes. 

Description : What is the significance of SF6 gas pressure in 6.6kV breakers?

Last Answer : Density gauge Green – correct SF6 pressure (3 –3.5bar) Yellow – pressure for breaking system fault current (refilling should be done) Red – SF6 pressure less than 2 bar, which indicates leak in the system. 

Description : What are the properties of SF6 gas?  

Last Answer : Physical properties 1. Colourless 2. Odorless 3. Non-toxic. Pure SF6 gas is not harmful to the health. 4. Non-inflammable. 5. Density- more gas density, 5 times ... advantages offer increased safety, reduction in size, weight, noiseless operation, easy installation, handling and maintenance. 

Description : In the illustration, the purpose of part B is to _________. EL-0033 A. increase resistance in series with the contacts as they close to prevent arcing B. create a magnetic field in the steel ... event of an overload D. provide ventilation to the contact when the breaker is close to rated capacity

Last Answer : Answer: B

Description : The purpose of a main switchboard circuit breaker's reverse-power trip is to _____________. A. prevent main circuit overload B. protect the circuit breaker blowout coil C. prevent alternator motorization D. prevent low voltage tripout

Last Answer : Answer: C

Description : What is the purpose of header breaker in water circuit?

Last Answer : The header breaker ensures oil pressure greater than that of water pressure always. Therefore there is no leak of water into oil.  

Description : Purpose of Local breaker back-up relay; type -CTIG

Last Answer : To safe guard against the drastic consequences of failure to clear faults rapidly, many power supply authorities install 2 independent systems of protection for major transmission lines. There remains however the ... reset, which enables the time delay to be set closer to the breaker trip-time. 

Description : What is the purpose of spring charging in 415 V breaker? 

Last Answer : If the breaker is to be closed and tripped manually the closing time and tripping time would vary from person to person. Also it would not be very fast. So spring charging is provided. It ... timings irrespective of the operator and its action is fast and closing and tripping time is very less. 

Description : Purpose of air lift pump is to (A) Compress air (B) Lift compressed air (C) Lift water from a well by using compressed air (D) Lift air under negative pressure

Last Answer : (C) Lift water from a well by using compressed air

Description : The purpose of an accumulator is to: a. Relieve excess pressure b. Store fluid under pressure c. Store compressed gas for tyre inflation d. Remove air from the system

Last Answer : b. Store fluid under pressure

Description : The purpose of an accumulator is to: a. Relieve excess pressure b. Store fluid under pressure c. Store compressed gas for tyre inflation d. Remove air from the system

Last Answer : b. Store fluid under pressure

Description : Which of the following procedures should be used to maintain a large electric motor during periods of inactivity? A. A thin layer of air-drying varnish should be applied on the windings. B. ... periodically to remove carbon dust. D. Space heaters should be used to prevent condensation of moisture.

Last Answer : Answer: D

Description : If a small electric motor has been submerged in saltwater for a short period of time, you should _____________. A. send it ashore for rewinding B. rinse it with warm freshwater and bake it dry ... and bake with internal heat D. clean it with carbon tetrachloride and blow it out with compressed air

Last Answer : Answer: B

Description : Compressed air should not be used to clean motor controller equipment because ________________. A. it may force metallic particles into coil insulation B. the surrounding area may need additional cleaning C. the air blast dries out insulation quickly D. a mask and respirator would be required

Last Answer : Answer: A

Description : Controller contacts should be routinely cleaned by ________. A. blowing with compressed air B. filing with a bastard file C. wiping with a clean dry cloth D. dressing with crocus cloth

Last Answer : Answer: C

Description : Grease coatings on electrical contact surfaces increase contact resistance and should be removed with a/an _______________. A. small wire brush B. compressed air jet C. clean dry cloth D. 10% solution carbon solvent and water

Last Answer : Answer: C

Description : Which of the following statements is true concerning the cleaning of electrical contacts? A. Compressed air should be used to blow out metallic dust. B. Magnetic brushes should be used to remove ... contact resistance. D. Delicate parts should be cleaned with a brush and an approved safety solvent.

Last Answer : Answer: D

Description : To repair a small electrical motor that has been submerged in saltwater, you should _____________. A. wash it with fresh water and apply an external source of heat B. renew the windings ... electrical parts with a carbon tetrachloride cleaning solvent and then blow dry the motor with compressed air

Last Answer : Answer: A

Description : Which of the following represents the accepted method of cleaning dust and foreign particles from electrical equipment while limiting damage to electric components? A. Carefully wiping off the components ... the components. D. Using carbon tetrachloride as a cleaning solvent to clean the components.

Last Answer : Answer: C

Description : SF6 gas (a) is yellow in colour (b) is lighter than air (c) is nontoxic (d) has pungent small (e) none of the above

Last Answer : (c) is nontoxic

Description : Name any two applications of following gases: (i) Nitrogen (ii) Hydrogen (iii) Sf6 (iv) Air. 

Last Answer : i) Applications of Nitrogen:  1. As a cooling agent. 2. To avoid oxidation. 3. Electrical insulating material (Gas) in electrical equipment. ii) Applications of Hydrogen:  1. High ... As a cooling agent in electrical machines. 2. Electrical insulating material (Gas) in electrical equipment. 

Description : Why we use Vacuum Circuit Breaker in High Transmission System and not Air Circuit Breaker?

Last Answer : A:Vacuum has high arc quenching property compare to air . The dielectric strength of vacuum is equal to 8 times than air . Hence vacuum circuit breaker is used in High voltage line and air circuit breaker is used in low voltage lines.

Description : What are the advantages of air blast circuit breaker over oil circuit breaker?

Last Answer : o The risk of fire is diminished o The arcing time is very small due to rapid buildup of dielectric strength between contacts o The arcing products are completely removed by the blast whereas oil deteriorates with successive operations

Description : What are the types of air blast circuit breaker?

Last Answer : Arial-blast type Cross blast Radial-blast

Description : Can you balance this SF4 plus F2 2 SF6?

Last Answer : Feel Free to Answer

Description : What is the shape of molecules SF6 and IF7 ?

Last Answer : SF6 is Octahedral IF7 is pentagonal Bipyramidal

Description : Why is SF4 more reactive than SF6 ?

Last Answer : Ans . SF4 has two unpaired electrons which it can donate further to extend its valency , hence it is reactive .’S’ in SF6 has maximum 6 0.S.

Description : Which of the following GHGs has the longest atmospheric life time? a) CO2 b) CFC c) Sulfur Hexafluoride (SF6) d) perfluorocarbon (PFC)

Last Answer : d) perfluorocarbon (PFC)

Description : Which of the following is not a greenhouse gas ? a) CFCs b) SO2 c) PFC d) SF6

Last Answer : b) SO2

Description : For which molecule can the bonding be described in terms of sp3 hybrid orbitals of the central atom? w) CH4 x) SF6 y) BF3 z) PCL5

Last Answer : ANSWER: B -- CH4

Description : The following is/are the characteristics of SF6 circuit breakers:  (A) It does not need an auxiliary breaking chamber (B) Short break time of 2 to 2.5 cycles (C) All of the above (D) None of the above

Last Answer : The following is/are the characteristics of SF6 circuit breakers:  (A) It does not need an auxiliary breaking chamber (B) Short break time of 2 to 2.5 cycles (C) All of the above (D) None of the above

Last Answer : SF6 gas is nontoxic.

Description : Moldboard consists of following types : a) General purpose. c) Sod or breaker b) Stubble. d) All of the above

Last Answer : All of the above

Description : Which of the following busbar arrangement is generally employed in distribution system: a) One-and-half breaker arrangement b) Main and transfer arrangement c) Ring main distribution system d) Single busbar arrangement system

Last Answer : Ans: C

Description : Coast Guard Regulations (46 CFR) require each switchboard to have ___________. A. non-conductive deck covering at the frount B. non-conductive deck coverings at the rear C. a name plate for each circuit breaker D. all the above

Last Answer : Answer: D

Description : Before any work on electrical or electronic equipment is performed, which of the following precautions should be carried out? A. De-energize the applicable switchboard bus. B. Bypass the interlocks. C. ... supply circuit breaker in the open position. D. Station a man at the circuit supply switch.

Last Answer : Answer: C

Description : Which of the synchroscope illustrations depicts the appropriate direction of rotation and position for closing the circuit breaker when paralleling AC generators? EL-0053 A. A B. B C. C D. D

Last Answer : Answer: D

Description : The schematic diagram shown in the illustration uses symbol 'A' to represent a/an _________. EL-0011 A. non-renewable fuse link B. circuit breaker coil C. overload relay coil D. thermal overload heater

Last Answer : Answer: D