For a fault in switchyard lightning arrestor, what protection will act?

For a fault in switchyard lightning arrestor, what protection will act?
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1 Answer

Answer :

Bus bar differential protection.  
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Related questions

Give the details of switchyard 220 kV CB, Isolator, CT, CVT and lightning arrestor.

Description : Give the details of switchyard 220 kV CB, Isolator, CT, CVT and lightning arrestor.  

Last Answer : 220 kV SF6 Circuit Breaker 1. Make - ABB 2. Air pressure blocking a. Close Block - 17.3 bar. b. Open block - 16.7 bar. c. Auto reclose block - 19 bar. 3. SF6 pressure block a. Alarm - 5. ... , storage and erection. Rated voltage : 216 kV rms. Operating voltage : 184 kV rms. 

In 220 kV switchyard why lightning arrestor should be properly grounded?

Description : In 220 kV switchyard why lightning arrestor should be properly grounded?

Last Answer : a. During lightning, surges should be discharged to ground, otherwise it will puncture the equipment insulation and it is possible only when lightning arrestor is grounded properly.  b. In order to make it effective ... kV. Soil resistivity a should be minimum and may be it is 3.5 ohm per meter.  

What is the difference between surge arrestor and lightning arrestor?

Description : What is the difference between surge arrestor and lightning arrestor?

Last Answer : LA is installed outside and the effect of lightning is grounded, where as surge arrestor installed inside panels comprising of resistors which consumes the energy and nullify the effect of surge.

What Is The Difference Between Surge Arrestor And Lightning Arrestor?

Description : What Is The Difference Between Surge Arrestor And Lightning Arrestor?

Last Answer : LA is installed outside and the effect of lightning is grounded,where as surge arrestor installed inside panels comprising of resistors which consumes the energy and nullify the effect of surge.

What is the difference between surge arrestor and lightning arrestor?

Description : What is the difference between surge arrestor and lightning arrestor?

Last Answer : A:Lightning Arrestor is installed outside and the effect of lightning is grounded where as surge arrestor installed inside panels comprising of resistors which consumes the energy and nullify the effect of surge.

What is the difference between surge arrestor and lightning arrestor?

Description : What is the difference between surge arrestor and lightning arrestor?

Last Answer : Lightning arrestor is installed outside and the effect of lightning is grounded, whereas surge arrestor installed inside panels comprising of resistors which consumes the energy and nullify the effect of surge.

What is the type of Lightning Arrestor?

Description : What is the type of Lightning Arrestor?

Last Answer : Station type, heavy duty, gap less zinc oxide.  

What is the purpose of lightning arrestor?

Description : What is the purpose of lightning arrestor? 

Last Answer : Due to lightning and switching surges high voltages are induced in the lines. If equipment's. Connected is subjected to this high voltage the insulation will fail. In order to avoid the failure of ... current to the earth. (It will divert the over voltages to earth and protect the substation)  

What is the type of lightning arrestor for GT?

Description : What is the type of lightning arrestor for GT? 

Last Answer : Zn O (zinc oxide) types.  

Write types of lightning arrestor.

Description : Write types of lightning arrestor.

Last Answer : a. Horn gap lightning arrestor. b. Oxide film lightning arrestor. c. Pellet lightning arrestor. d. Thyrite lightning arrestor.

How does a lightning arrestor work?

Description : How does a lightning arrestor work?

Last Answer : ANSWER I: Lightning, is a form of visible discharge of electricity between rain clouds or between a rain cloud and the earth. The electric discharge is seen in the form of a brilliant arc, ... a cone of protection, which has a ground radius approximately, equal to its height above the ground.

Why Stones/Gravel is used in electrical Switchyard

Description : Why Stones/Gravel is used in electrical Switchyard

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What is the rating of switchyard battery charger and batteries?

Description : What is the rating of switchyard battery charger and batteries? 

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What is the various design of CT's in switchyard?

Description : What is the various design of CT's in switchyard?

Last Answer : Bus coupler CT's- live tank design 2000-1000A/1A All other CT's- dead tank design 800-600-400A/1A - lines and GT. 125A/1A – SUT

Why switchyard is located indoors of coastal plants?

Description : Why switchyard is located indoors of coastal plants?

Last Answer : Saline atmosphere will deposit on the insulators causing its flashover. The building kept under positive pressure compared with outside thus preventing the (saline) air entering from outside to inside the building. 

Give switchyard specification.

Description : Give switchyard specification. 

Last Answer : 1. Type : Out door. 2. Scheme : Double main bus bar with bypass switching scheme is provided. This allows maintenance of one bus or one CB without interruption. 3. Normal voltage : 220 kV. 4. Rated ... 11. CB - SF6 12. Isolator - motor operated rotating type. 13. Number of bays - 16 Nos. 

Why indoor switchyard is provided in MAPS?

Description : Why indoor switchyard is provided in MAPS?  

Last Answer : The salt contamination in the switchyard is avoided by providing indoor switchyard in MAPS. Because the plant is just 300 metres away from the seashore and the atmosphere is saline. This salt will get ... and to have low cost of installation and spare parts of aluminium indoor switchyard is used. 

Emulsifier protection is associated with: a) Grounding protection b) Dielectric strength protection of cables and conductors c) Lightning protection d) Fire protection

Description : Emulsifier protection is associated with: a) Grounding protection b) Dielectric strength protection of cables and conductors c) Lightning protection d) Fire protection

Last Answer : Ans: D

Where should the lighting arrestor is placed in distribution lines?

Description : Where should the lighting arrestor is placed in distribution lines?

Last Answer : Near distribution transformers and out going feeders of 11kv and incoming feeder of 33kv and near power transformers in sub-stations.

Where should the lighting arrestor be placed in distribution lines?

Description : Where should the lighting arrestor be placed in distribution lines?

Last Answer : A:Near distribution transformers and out going feeders of 11kv and incomming feeder of 33kv and near power transformers in sub-stations.

Which of the following statements is incorrect ? (a) Lightning arrestors are used before the switchgear (b) Shunt reactors are used as compensation reactors (c) The peak short current is (1.8 xV2) times the A.C. component (d) The MVA at fault is equal to base MVA divided by per unit equivalent fault reactance

Description : Which of the following statements is incorrect ? (a) Lightning arrestors are used before the switchgear (b) Shunt reactors are used as compensation reactors (c) The peak short current is (1.8 xV2) ... component (d) The MVA at fault is equal to base MVA divided by per unit equivalent fault reactance

Last Answer : (a) Lightning arrestors are used before the switchgear

Which of the following statements is incorrect? (a) Station batteries are used to operate relay only (b) The lightning arresters are basically surge diverters (c) An impedance relay has maximum fault current when fault occurs near the relay (d) A high speed relay has an operation of 1 to 2 cycles

Description : Which of the following statements is incorrect? (a) Station batteries are used to operate relay only (b) The lightning arresters are basically surge diverters (c) An impedance relay has maximum fault current when fault occurs near the relay (d) A high speed relay has an operation of 1 to 2 cycles

Last Answer : (a) Station batteries are used to operate relay only

For protection of rotating machines against lightning surges _______ is used.

Description : For protection of rotating machines against lightning surges _______ is used.  (1) lightning arrester (2) capacitor (3) combination of lightning arrester and capacitor (4) lightning conductor and arrester

Last Answer : For protection of rotating machines against lightning surges combination of lightning arrester and capacitor is used. 

_________ is one of the more expensive and complex areas of network computing. a) Multi-Factor Authentication b) Fault tolerance c) Identity protection d) All of the mentioned

Description : _________ is one of the more expensive and complex areas of network computing. a) Multi-Factor Authentication b) Fault tolerance c) Identity protection d) All of the mentioned

Last Answer : Identity protection

The inverse definite mean time relays are used for over current and earth fault protection of transformer against (a) heavy loads (b) internal short-circuits (c) external short-circuits (d) all of the above

Description : The inverse definite mean time relays are used for over current and earth fault protection of transformer against (a) heavy loads (b) internal short-circuits (c) external short-circuits (d) all of the above

Last Answer : (b) internal short-circuits

Large internal faults are protected by (a) merz price percentage differential protection (b) mho and ohm relays (c) horn gaps and temperature relays (d) earth fault and positive sequence relays

Description : Large internal faults are protected by (a) merz price percentage differential protection (b) mho and ohm relays (c) horn gaps and temperature relays (d) earth fault and positive sequence relays

Last Answer : (a) merz price percentage differential protection

Explain fault bus protection scheme.

Description : Explain fault bus protection scheme.

Last Answer : Fault bus protection of busbar: In this scheme, the substation is so designed that every fault on the bus bar is converted to earth fault. Under normal operating conditions, there is no current flowing ... This results in operation of relay to actuate trip coil of CB to trip the circuit.

Explain with necessary diagram the earth fault protection of power and auxiliary circuit.

Description : Explain with necessary diagram the earth fault protection of power and auxiliary circuit.

Last Answer : i) Earth fault protection for power circuit in Loco: When any earth fault occurs in the traction power circuit the fault current flows through the relay coil as the battery negative is ... temporarily by isolating the relay which connects the star point to earth through a high resistance.

Draw a neat sketch of earth fault protection of auxiliary circuit of electric loco. State the function of relay and isolating resistance.

Description : Draw a neat sketch of earth fault protection of auxiliary circuit of electric loco. State the function of relay and isolating resistance.

Last Answer : Ans: Earth fault protection for auxiliaries in Loco: Function of relay: The earth fault occurring anywhere in the auxiliary circuit gets monitored by the relay which acts to trip the main CB. Function of ... star point to earth through a high resistance so that the relay operation is avoided.

The inverse definite mean time relays are used for over current and earth fault protection of transformer against?

Last Answer : The inverse definite mean time relays are used for over current and earth fault protection of transformer against internal short-circuits.

What is the difference between flash back arrestor and check valve?

Description : What is the difference between flash back arrestor and check valve? 

Last Answer : A check valve allows flow in one direction only. This prevents oxygen reaching acetylene cylinder and acetylene reaching oxygen cylinder in the event of blockage in the torch or line or pressure variations.

Which of the following has highest diversity factor? a) Domestic lightning b) Commercial lightning c) Industrial power d) Domestic power

Description : Which of the following has highest diversity factor? a) Domestic lightning b) Commercial lightning c) Industrial power d) Domestic power

Last Answer : Ans: A

How standard lightning impulse wave is represented?

Description : How standard lightning impulse wave is represented?

Last Answer : Answer: Standard Lighting impulse wave is represented by 1.2/50 micro sec wave

What is meant by impulse ratio of any lightning arrester?

Description : What is meant by impulse ratio of any lightning arrester?

Last Answer : Impulse ratio of any lightning arrester is the ratio of breakdown voltage of the wave of special duration to breakdown voltage of a 50Hz wave

What is meant by Lightning arrester or surge diverter?

Description : What is meant by Lightning arrester or surge diverter?

Last Answer : A Surge Diverter is a device that is connected between line and earth, i.e, in parallel with the equipment under protection at the substation. It limits the duration and amplitude of the follow current

What is the difference between the lightning arrester and surge absorber?

Description : What is the difference between the lightning arrester and surge absorber?

Last Answer : Lightning arrester limits the duration and amplitude of the follow current while a surge absorber reduces the steepness of the wave front for a particular surge

How generator is protected from switching surges and lightning surges?

Description : How generator is protected from switching surges and lightning surges? 

Last Answer : Surge capacitor and lightning arrestor.  

When the electric current is passed through conducting solution, there is change in colour of the solution. This indicates a) chemical effect of current b) the heating effect of current c) the magnetic effect of current d) the lightning effect of current

Description : When the electric current is passed through conducting solution, there is change in colour of the solution. This indicates a) chemical effect of current b) the heating effect of current c) the magnetic effect of current d) the lightning effect of current

Last Answer : a) chemical effect of current

When earth fault occurs: a) voltage potential at the earth mat increases due to grounding b) voltage potential at the earth mat decreases due to grounding c) voltage potential at the earth mat remains zero irrespective of fault d) none of the above

Description : When earth fault occurs: a) voltage potential at the earth mat increases due to grounding b) voltage potential at the earth mat decreases due to grounding c) voltage potential at the earth mat remains zero irrespective of fault d) none of the above

Last Answer : Ans: A

Moisture absorbed in the windings or condensed on the surface of electrical machinery insulation ________. A. is good for long term preserving since most insulation is organic and contains some amount B. lowers the insulation value and is a common cause of fault grounds in idle machines C. will enhance insulation resistance only if it is fresh water and contains no salt D. reduces the amount of current supplied or drawn by the machine so horsepower is limited

Description : Moisture absorbed in the windings or condensed on the surface of electrical machinery insulation ________. A. is good for long term preserving since most insulation is organic and contains some amount B. ... D. reduces the amount of current supplied or drawn by the machine so horsepower is limited

Last Answer : Answer: B

When a console indicating lamp burns out, attempts to renew it should not be made while maneuvering because _______________. A. the new lamp may be of a higher wattage and cause heat damage to the lens B. removing a faulty lamp usually causes an alarm to sound on the bridge C. attention should be paid only to engine orders D. a socket/wiring fault may cause a ground or short circuit to shut down a vital function

Description : When a console indicating lamp burns out, attempts to renew it should not be made while maneuvering because _______________. A. the new lamp may be of a higher wattage and cause heat damage to the lens ... D. a socket/wiring fault may cause a ground or short circuit to shut down a vital function

Last Answer : Answer: D

An open-circuit fault between the pressure switch and the 'annunciator module' shown in the illustration would cause the alarm circuit to react in the same manner as if ___________. EL-0094 A. 3.5 volts were applied to the 'setpoint module' B. 'reduction gear lube oil pressure' fell below switch setting C. 50 PSI were applied to the 'setpoint module' D. the pressure switch closed

Description : An open-circuit fault between the pressure switch and the 'annunciator module' shown in the illustration would cause the alarm circuit to react in the same manner as if ___________. EL-0094 A. 3.5 ... below switch setting C. 50 PSI were applied to the 'setpoint module' D. the pressure switch closed

Last Answer : Answer: B

Action carried out by the relay and circuit breaker during fault condition?

Description : Action carried out by the relay and circuit breaker during fault condition?

Last Answer : Answer: After the relay sensing the fault condition, relay operates and close the trip coils. The effect of this will be circuit breaker operate to open the contacts.

State the significance of double line fault.

Description : State the significance of double line fault.

Last Answer : It has no zero sequence component and the positive and negative sequence networks are connected in parallel.

State the significance of single line to ground fault.

Description : State the significance of single line to ground fault.

Last Answer : In single line to ground fault all the sequence networks are connected in series. All the sequence currents are equal and the fault current magnitude is three times its sequence currents.

What is meant by fault calculations

Description : What is meant by fault calculations

Last Answer : The fault condition of a power system can be dived into subtransient, transient and steady state periods. The currents in the various parts of the system and in the fault are different in ... for various types of faults at various locations in the system are commenly reffered as fault calculations.

What is symmetrical and unsymmetrical fault?

Description : What is symmetrical and unsymmetrical fault?

Last Answer : The fault is called symmetrical fault if the fault current is equal in all the phases. The fault is called unsymmetrical fault if the fault current is not equal in all the phases.

List the various types of series and shunt fault?

Description : List the various types of series and shunt fault?

Last Answer : Shunt faults are, Line to ground fault line to line fault, double line to ground fault, three phase fault. Series faults are, One open conductor fault Two open conductor fault

Why fault accurs in a power system?

Description : Why fault accurs in a power system?

Last Answer : The fault occur in a power system due to insulation failure of equipments, flashover of lines initiated by a lightning stroke, due to permanent damage to conductors and towers

What is meant by a fault?

Description : What is meant by a fault?

Last Answer : A fault in a circuit is any failure which interferes with the normal flow of current. The faults are associated with abnormal change in current, voltage and frequency of the power systwm. The faults may ... to sence the faults to isolate the faulty part from the healthy part in the event of fault.