Which of the following circuit breakers is preferred for EHT application: -

Which of the following circuit breakers is preferred for EHT application: - 

a) Air blast circuit breakers b) Minimum oil circuit breakers c) Bulk oil circuit breakers d) SF6 oil circuit breakers
by

2 Answers

Answer :

Which of the following circuit breakers is preferred for EHT application: -  SF6 oil circuit breakers

by

Answer :

Air circuit breaker 
by

Related questions

Under Ground EHT cables can carry voltage above _________.

Description : Under Ground EHT cables can carry voltage above _________. A. 32 kV B. 11 kV C. 16 kV D. None

Last Answer : Under Ground EHT cables can carry voltage above 11 kV.

What is the full form of 'EHT' ? -How To ?

Description : What is the full form of 'EHT' ? -How To ?

Last Answer : The full form of 'EHT' is Extra High Tension

Three resistors connected in parallel have values of 12 kΩ, 20kΩ, and 30kΩ. What is the equivalent resistance? A37. 6kΩ Q38. Two resistors connected in parallel have values of 10 kΩ and 30kΩ. What is eht equivalent resistance?

Description : Three resistors connected in parallel have values of 12 kΩ, 20kΩ, and 30kΩ. What is the equivalent resistance? A37. 6kΩ Q38. Two resistors connected in parallel have values of 10 kΩ and 30kΩ. What is eht equivalent resistance?

Last Answer : 7.5kΩ

Magnetic circuit breakers use _________

Description : Magnetic circuit breakers use _________ A) Permanent magnets B) Earth magnets C) Solenoid D) All the above

Last Answer : Magnetic circuit breakers use Solenoid 

In general AC distribution systems, arc interruption in vacuum circuit breakers are designed to function in a...

Description : In general AC distribution systems, arc interruption in vacuum circuit breakers are designed to function in a time period of (a) One cycle (b) Two to three cycles (c) Within ten cycles (d) None of the above

Last Answer : In general AC distribution systems, arc interruption in vacuum circuit breakers are designed to function in a time period of One cycle

Low voltage circuit breakers have rated voltage of less than___________-.

Description : Low voltage circuit breakers have rated voltage of less than___________-. A. 220 V B. 400V C. 1000 V D. 10,000 V.

Last Answer : Low voltage circuit breakers have rated voltage of less than 1000 V.

They fall on the cottage circuit breakers

Description : When I run more electrical appliances, the circuit breakers go out and I have to go "throw them". How to fix it? Call us electricians to put stronger circuit breakers? Or how is it handled?

Last Answer : calculate the power consumption of the appliances (current must be lower than the value of the circuit breaker (s)) the question is what appliances are involved (some, typically motors, need more ... "electricity", invite electricians and have specific options and needs explained "on the spot". ;-)

What are circuit breakers for?

Description : When there's a storm outside and it hits the lead, will it help me that I have circuit breakers at home? Or what will burn in the drawer so?

Last Answer : the circuit breaker will not help, even the switched-off switch in the socket will not help, it may not burn out, but the electronics may be destroyed - even invisibly from the outside -

Where are all the controls on most circuit breakers?

Description : Where are all the controls on most circuit breakers?

Last Answer : The only control on a circuit breaker is its on/off/reset leveror button.

How do circuit breakers keep the wires in an electric circuit from overheating?

Description : How do circuit breakers keep the wires in an electric circuit from overheating?

Last Answer : They reduce the flow of electrons.

How do circuit breakers keep the wires in an electric circuit from overheating?

Description : How do circuit breakers keep the wires in an electric circuit from overheating?

Last Answer : They reduce the flow of electrons.

Are circuit breakers more expensive the better they are?

Description : Are circuit breakers more expensive the better they are?

Last Answer : On one hand you don't want to search for the absolute cheapest circuit breaker you can find.On the other this is a competitive business and most circuit breakers have similar quality and price ranges

Accidental grounds in a shipboard electrical system must be repaired as soon as possible as they will ____________. A. result in immediate power outages B. damage circuit breakers C. appear on the ground detection system D. damage insulation and may cause outages

Description : Accidental grounds in a shipboard electrical system must be repaired as soon as possible as they will ____________. A. result in immediate power outages B. damage circuit breakers C. appear on the ground detection system D. damage insulation and may cause outages

Last Answer : Answer: D

A ground is indicated by the ground-detecting system on the main electrical switchboard. The FIRST step in locating the actual ground is to _____________. A. close all circuit breakers in the distribution panel until the ground detector indicates normal B. open the individual circuit breakers, one by one until the ground detection system indicates normal C. change over generators D. check each circuit with a megohmmeter

Description : A ground is indicated by the ground-detecting system on the main electrical switchboard. The FIRST step in locating the actual ground is to _____________. A. close all circuit breakers in ... ground detection system indicates normal C. change over generators D. check each circuit with a megohmmeter

Last Answer : Answer: B

During maintenance of circuit breakers, _______________. A. always smooth roughened contact surfaces with a file B. never pass more than rated breaker current through the overload heater element C. inspect for wear and misalignment of main contacts D. assume heater elements installed are of correct size

Description : During maintenance of circuit breakers, _______________. A. always smooth roughened contact surfaces with a file B. never pass more than rated breaker current through the overload heater element C. ... wear and misalignment of main contacts D. assume heater elements installed are of correct size

Last Answer : Answer: C

Undervoltage trips are frequently installed on switchboard circuit breakers to trip ____________. A. out generators in the event of severe arcing or sparking B. out generators when there is reversal of power in the main circuit C. the breaker if the generator overspeeds by 5%, but continues to run D. out generators when there is low voltage in the main circuit

Description : Undervoltage trips are frequently installed on switchboard circuit breakers to trip ____________. A. out generators in the event of severe arcing or sparking B. out generators when there is reversal of power ... , but continues to run D. out generators when there is low voltage in the main circuit

Last Answer : Answer: D

Periodic testing of circuit breakers is necessary to assure that a correctly rated and properly installed unit _________________. A. can trip faster as it increases in age B. will continue to provide the original degree of protection C. does not exceed its interrupting capacity D. be able to withstand at least 125% of applied voltage

Description : Periodic testing of circuit breakers is necessary to assure that a correctly rated and properly installed unit _________________. A. can trip faster as it increases in age B. will continue to provide ... not exceed its interrupting capacity D. be able to withstand at least 125% of applied voltage

Last Answer : Answer: B

You can determine if a circuit breaker has tripped by ________________. A. examining the position of the handle B. checking for which of the breakers is warm C. looking for a burned-out link D. all of the above

Description : You can determine if a circuit breaker has tripped by ________________. A. examining the position of the handle B. checking for which of the breakers is warm C. looking for a burned-out link D. all of the above

Last Answer : Answer: A

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

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

A 'dead front' switchboard is one _____________. A. without switches on it B. with insulated switches and no exposed terminals C. without circuit breakers D. without safety hand rails nor rubber mats

Description : A 'dead front' switchboard is one _____________. A. without switches on it B. with insulated switches and no exposed terminals C. without circuit breakers D. without safety hand rails nor rubber mats

Last Answer : Answer: B

Protection against sustained overloads occurring in molded-case circuit breakers is provided by a/an __________. A. overvoltage release B. thermal acting trip C. thermal overload relay D. current overload relay

Description : Protection against sustained overloads occurring in molded-case circuit breakers is provided by a/an __________. A. overvoltage release B. thermal acting trip C. thermal overload relay D. current overload relay

Last Answer : Answer: B

The purpose of a short circuit forcing module (short time trip) installed in a branch line is to provide ____________. A. high speed clearance of low impedance short circuits in the branch B. continuity of service on main bus under short circuit conditions in a branch C. isolation of short circuits by selective tripping of branch circuit breakers D. all of the above

Description : The purpose of a short circuit forcing module (short time trip) installed in a branch line is to provide ____________. A. high speed clearance of low impedance short circuits in the branch B. ... C. isolation of short circuits by selective tripping of branch circuit breakers D. all of the above

Last Answer : Answer: D

What are different types of circuit breakers employed in thermal power plant?

Description : What are different types of circuit breakers employed in thermal power plant?

Last Answer : Answer: For low voltage operation 415/220V vacuum circuit breakers or air break circuit breakers are employed. For voltage ratings about 6.6kV and beyond SF6 circuit breakers are employed.

What are different types of circuit breakers employed in thermal power plant?

Description : What are different types of circuit breakers employed in thermal power plant?

Last Answer : For low voltage operation 415/220V vacuum circuit breakers or air break circuit breakers are employed. For voltage ratings about 6.6kV and beyond SF6 circuit breakers are employed.

Why Isolation switches are provided along with the circuit breakers?

Description : Why Isolation switches are provided along with the circuit breakers?

Last Answer : Isolation switches are provided for separating the disconnected element from the live portion of the system for the purpose of safety

Air Blast Circuit Breakers Advantages Disadvantages

Description : Air Blast Circuit Breakers Advantages Disadvantages

Last Answer : Air Blast Circuit Breakers Advantages Disadvantages In air blast circuit breakers, compressed air at a pressure of 20-30 kg/cm2 is employed as an arc quenching medium. Air blast circuit breakers ... air blast circuit breaker current chopping problem exists There is a problem of re-striking voltage

Why we need isolation transformers in power circuit ? why cant we use breakers to isolate?

Description : Why we need isolation transformers in power circuit ? why cant we use breakers to isolate?

Last Answer : In Isolation transformer is used, if there is change in parameter values of any side, the other side parameters will remain unchanged.

How direct tests are conducted in circuit breakers?

Description : How direct tests are conducted in circuit breakers?

Last Answer : Using a short circuit generator as the source. Using the power utility system or network as the source.

State the different types of circuit breakers.

Description : State the different types of circuit breakers.

Last Answer : Air ,oil,vacuum circuit breakers.

Write the classifications of test conducted on circuit breakers.

Description : Write the classifications of test conducted on circuit breakers.

Last Answer : Type test Routine test Reliability test Commissioning test

Write the classification of circuit breakers based on the medium used for arc extinction?

Description : Write the classification of circuit breakers based on the medium used for arc extinction?

Last Answer : Air break circuit breaker Oil circuit breaker Minimum oil circuit breaker Air blast circuit breaker SF6 circuit breaker Vacuum circuit breaker

In which of the following item(s), spring is used to store energy. (A) clocks (B) toys (C) circuit breakers (D) all of the above

Description : In which of the following item(s), spring is used to store energy. (A) clocks (B) toys (C) circuit breakers (D) all of the above

Last Answer : (D) all of the above

What are the protections provided in PMCC circuit breakers?

Description : What are the protections provided in PMCC circuit breakers?

Last Answer : 1. IDMT O/C (CDG 34). 2. IDMT E/F (CDG 11).  3. Under voltage (40% of 110V). 

Air blast circuit breakers for 400 kV power system are designed to operate in (a) 100 microsecond (b) 50 millisecond (c) 0.5 sec (d) 0.1 sec

Description : Air blast circuit breakers for 400 kV power system are designed to operate in (a) 100 microsecond (b) 50 millisecond (c) 0.5 sec (d) 0.1 sec

Last Answer : (b) 50 millisecond

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

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

Insulation resistance of high voltage circuit breakers is more than (a) 1 mega ohms (b) 10 mega ohms (c) 100 mega ohms (d) 500 mega ohms

Description : Insulation resistance of high voltage circuit breakers is more than (a) 1 mega ohms (b) 10 mega ohms (c) 100 mega ohms (d) 500 mega ohms

Last Answer : (c) 100 mega ohms

The time of closing the cycle, in modern circuit breakers is (a) 0.003 sec (b) 0.001 sec (c) 0.01 sec (d) 0.10 sec (e) none of the above

Description : The time of closing the cycle, in modern circuit breakers is (a) 0.003 sec (b) 0.001 sec (c) 0.01 sec (d) 0.10 sec (e) none of the above

Last Answer : (a) 0.003 sec

The current zero interruption, in oil and air blast circuit breakers, is achieved by (a) lengthening of the gap (b) cooling and blast effect (c) both (a) and (b) (d) deionizing the oil with forced air (e) none of the above

Description : The current zero interruption, in oil and air blast circuit breakers, is achieved by (a) lengthening of the gap (b) cooling and blast effect (c) both (a) and (b) (d) deionizing the oil with forced air (e) none of the above

Last Answer : (c) both (a) and (b)

Circuit breakers are essentially (a) current carrying contacts called electrodes (b) arc extinguishers (c) circuits to break the system (d) transformers to isolate the two systems (e) any of the above

Description : Circuit breakers are essentially (a) current carrying contacts called electrodes (b) arc extinguishers (c) circuits to break the system (d) transformers to isolate the two systems (e) any of the above

Last Answer : (a) current carrying contacts called electrodes

Circuit breakers usually operate under (a) transient state of short-circuit current (b) sub-transient state of short-circuit current (c) steady state of short-circuit current (d) after D.C. component has ceased

Description : Circuit breakers usually operate under (a) transient state of short-circuit current (b) sub-transient state of short-circuit current (c) steady state of short-circuit current (d) after D.C. component has ceased

Last Answer : (a) transient state of short-circuit current

Fault diverters are basically (a) fuses (b) relays (c) fast switches (d) circuit breakers

Description : Fault diverters are basically (a) fuses (b) relays (c) fast switches (d) circuit breakers

Last Answer : (c) fast switches

On which of the following routine tests are conducted ? (a) Oil circuit breakers (b) Air blast circuit breakers (c) Minimum oil circuit breakers (d) All of the above

Description : On which of the following routine tests are conducted ? (a) Oil circuit breakers (b) Air blast circuit breakers (c) Minimum oil circuit breakers (d) All of the above

Last Answer : (d) All of the above

. If the power distribution system shown in figure 2-22 uses selective tripping, what is the time delay rating for each of the circuit breakers shown?

Description : . If the power distribution system shown in figure 2-22 uses selective tripping, what is the time delay rating for each of the circuit breakers shown?

Last Answer : CB1-long time delay; CB2, CB3-short time delay; CB4 through

What are the three time delay ratings for circuit breakers?

Description : What are the three time delay ratings for circuit breakers?

Last Answer : Instantaneous, short time delay, and long time delay.

The Use of high speed circuit breakers

Description : The Use of high speed circuit breakers  A) Reduces the short circuit current B) Improves system stability C) Decreases system stability D) Increases the short circuit current

Last Answer : Q

Which of the following circuit breakers has high reliability & minimum maintenance?

Description : Which of the following circuit breakers has high reliability & minimum maintenance?  (A) Bulk oil type CB (B) Air blast CB (C) Vacuum CB (D) Sulphur hexafluoride CB 

Last Answer : Which of the following circuit breakers has high reliability & minimum maintenance?  (A) Bulk oil type CB (B) Air blast CB (C) Vacuum CB (D) Sulphur hexafluoride CB 

The following is/are the characteristics of SF6 circuit breakers:

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

Air blast circuit breakers for 400 kV power system are designed to operate in?

Last Answer : Air blast circuit breakers for 400 kV power system are designed to operate in 50 millisecond.