main parts of Relay

main parts of Relay
by
retagged

1 Answer

Answer :

Coil, plunger, contacts, springs, connecting terminals and enclosure.
by

Related questions

Buchholz relay is used as a safety device with respect to which of the following?

Description : Buchholz relay is used as a safety device with respect to which of the following? A) Audio transformers B) Oil filled power transformers C) Air core transformer D) None of these

Last Answer : Buchholz relay is used as a safety device with respect to which of the following? A) Audio transformers B) Oil filled power transformers C) Air core transformer D) None of these

what is reverse power relay?

Description : what is reverse power relay?

Last Answer : Thereverse powerrelay is a directional protective relay that prevents power from flowing in the reverse direction. Read our article going back ... it all to be up to date. And if you do, read it anyway just to check if youreallydo!

Fuel Pump Relay

Description : Fuel Pump Relay

Last Answer : Some car owners immediately suspect a fuel pump failure when their cars stall. However, there are many other engine problems that may resemble a fuel pump failure, such as restricted fuel filters, smashed ... advisable to bring your car to the repair shop so that the whole engine can be checked.

The purpose of the restraining coil in a biased differential relay is

Description : The purpose of the restraining coil in a biased differential relay is  (A) To reduce CT saturation during fault.  (B) To increase the sensitivity of the relay.  (C) To match the transformation ratio.  (D) To limit the spill current through the relay during heavy external fault.

Last Answer : d

A relay used for protection of motors against overload is :

Description : A relay used for protection of motors against overload is :  (A) Impedance relay (B) Electromagnetic attraction type (C) Thermal relay (D) Buchholz's relay

Last Answer : D

A relay has a rating of 5 A, 2.2 sec IDMT and a relay setting of 125% TMS = 0.6. It is connected to a supply

Description : A relay has a rating of 5 A, 2.2 sec IDMT and a relay setting of 125% TMS = 0.6. It is connected to a supply circuit through a C.T. 400/5 ratio. The fault current is 4000 A. The operating current of the relay is

Last Answer : A relay has a rating of 5 A, 2.2 sec IDMT and a relay setting of 125% TMS = 0.6. It is connected to a supply circuit through a C.T. 400/5 ratio. The fault current is 4000 A. The operating current of the relay is 6.25A

The operating time of instantaneous relay is

Description : The operating time of instantaneous relay is

Last Answer : The operating time of instantaneous relay is 0.1 sec

What is the difference between relay and contactor?

Description : What is the difference between relay and contactor?

Last Answer : Relay have smaller ratings. Contactor is a high rating relay.

A negative sequence relay is used for protection of

Description : A negative sequence relay is used for protection of  (1) Generator (3) Motor (2) Transformer (4) Long Transmission lines

Last Answer : A negative sequence relay is used for protection of Generator 

Buchholz relay is

Description : Buchholz relay is  (1) located in the conservator tank  (2) located in the transformer tank itself  (3) connected in the pipe connecting main tank of transformer and conservator  (4) installed in the circuit breaker

Last Answer : Buchholz relay is connected in the pipe connecting main tank of transformer and conservator 

To prevent mal-operation of differentially connected relay while energizing a transformer, the relay

Description : To prevent mal-operation of differentially connected relay while energizing a transformer, the relay restraining coil is based with  (1) second harmonic current  (2) third harmonic current  (3) fifth harmonic current  (4) seventh harmonic current

Last Answer : To prevent mal-operation of differentially connected relay while energizing a transformer, the relay restraining coil is based with  second harmonic current 

Reactance relay is normally preferred for protection against

Description : Reactance relay is normally preferred for protection against

Last Answer : Reactance relay is normally preferred for protection against earth faults

In the induction type directional over current relay, when a short-circuit occurs in the circuit

Description : In the induction type directional over current relay, when a short-circuit occurs in the circuit (A) power flows in reverse direction (B) power flows in normal direction (C) directional power element does not operate (D) over current element is not energized

Last Answer : In the induction type directional over current relay, when a short-circuit occurs in the circuit power flows in reverse direction

A solid state relay

Description : A solid state relay (A) withstands voltage transients (B) does not require auxiliary dc supply (C) provide low burden on CT and P (D) does not provide earth fault protection

Last Answer : A solid state relay provide low burden on CT and P

A reactance relay is

Description : A reactance relay is (A) Voltage restrained directional relay (B) Directional restrained over-current relay (C) Voltage restrained over current relay (D) Directional restrained over voltage relay

Last Answer : A reactance relay is Directional restrained over-current relay

The torque produced in induction type relay (shaded pole structure) is?

Last Answer : The torque produced in induction type relay (shaded pole structure) is inversely proportional to the square of the current.

Admittance relay is _______ relay.

Last Answer : Admittance relay is directional relay.

The relay with inverse time characteristic will operate within?

Last Answer : The relay with inverse time characteristic will operate within 5 to 10 sec.

The under voltage relay can be used for?

Last Answer : The under voltage relay can be used for generators, busbars, transformers, motors.

Which relay is preferred for phase fault on short transmission line?

Last Answer : Reactance relay is preferred for phase fault on short transmission line.

Induction cup relay is operated due to changes in?

Last Answer : Induction cup relay is operated due to changes in current, voltage, impedance.

Interruption of large currents by relay requires?

Last Answer : Interruption of large currents by relay requires arc suppressing blow out coils, wide separation of the opened contacts, high speed opening of contacts.

Overheating of relay contacts or contact born out is due to?

Last Answer : Overheating of relay contacts or contact born out is due to slow making and breaking of load circuit contacts, foreign matter on the contact surface, too low contact pressure.

A differential relay measures the vector difference between?

Last Answer : A differential relay measures the vector difference between two or more similar electrical quantities.

Burden of a protective relay is the power?

Last Answer : Burden of a protective relay is the power absorbed by the circuit of relay.

In order that current should flow without causing excessive heating or voltage drop, the relay contacts should?

Last Answer : In order that current should flow without causing excessive heating or voltage drop, the relay contacts should have low contact resistance, be clean and smooth, be of sufficient size and proper shape.

The relay operating speed depends upon?

Last Answer : The relay operating speed depends upon the spring tension, the rate of flux built up, armature core air gap.

A Buchholz relay can be installed on?

Last Answer : A Buchholz relay can be installed on oil cooled transformers.

Buchholz's relay gives warning and protection against?

Last Answer : Buchholz's relay gives warning and protection against electrical fault inside the transformer itself.

How do relay works ?

Description : How do relay works ?

Last Answer : Relay working like contact it is noise less 

What is the use of Buchholz relay in transformer?

Description : What is the use of Buchholz relay in transformer?

Last Answer : This is a transformer that is used to step up and down current. 

What is the difference between a switch and a relay?

Description : What is the difference between a switch and a relay?

Last Answer : Switch is simply a mechanical contact mechanism and relay is a electromagnetic switch . Switch can be direct mechanically turn on and off but relay can be operated by energising coil .

The operating torque of the upper induction disc-type element, or timer element, of an AC reverse power relay is obtained from ____________. A. the main bus B. a separate battery source C. line voltage D. electromagnets

Description : The operating torque of the upper induction disc-type element, or timer element, of an AC reverse power relay is obtained from ____________. A. the main bus B. a separate battery source C. line voltage D. electromagnets

Last Answer : Answer: D

The purpose of the reverse power relay, provided on a ship's service alternator panel, is to trip the circuit in the event of ______________. A. main circuit overload B. high power transfer C. generator overspeeding D. alternator motorization

Description : The purpose of the reverse power relay, provided on a ship's service alternator panel, is to trip the circuit in the event of ______________. A. main circuit overload B. high power transfer C. generator overspeeding D. alternator motorization

Last Answer : Answer: D

A reverse-current relay will prevent AC generator motorization by ____________. A. automatically redirecting the load B. automatically speeding up the prime mover C. tripping the panel board main switch D. tripping the generator circuit breaker

Description : A reverse-current relay will prevent AC generator motorization by ____________. A. automatically redirecting the load B. automatically speeding up the prime mover C. tripping the panel board main switch D. tripping the generator circuit breaker

Last Answer : Answer: D

The timer element found in a reverse power relay obtains its operating torque via _____________. A. line voltage B. the main bus C. electromagnets D. a separate battery source

Description : The timer element found in a reverse power relay obtains its operating torque via _____________. A. line voltage B. the main bus C. electromagnets D. a separate battery source

Last Answer : Answer: C

The part of the shipboard electrical system used to control the distribution of power to the branch circuits, is the _____________. A. bridge control panel B. disconnect links C. governor relay box D. main switchboard

Description : The part of the shipboard electrical system used to control the distribution of power to the branch circuits, is the _____________. A. bridge control panel B. disconnect links C. governor relay box D. main switchboard

Last Answer : Answer: D

Regarding an AC generator connected to the main electrical bus; as the electric load and power factor vary, a corresponding change is reflected in the generator armature reaction. These changes in armature reaction are compensated for by the __________ A. governor speed droop setting B. voltage regulator C. balance coil D. phase-balance relay

Description : Regarding an AC generator connected to the main electrical bus; as the electric load and power factor vary, a corresponding change is reflected in the generator armature reaction. These changes in ... . governor speed droop setting B. voltage regulator C. balance coil D. phase-balance relay

Last Answer : Answer: B

Which of the following statements represents the main difference between a relay and a contactor? A. Contactors control current and relays control voltage. B. A relay is series connected and a contactor is parallel connected. C. Contactors can handle heavier loads than relays. D. Contactors are made from silver and relays are made from copper.

Description : Which of the following statements represents the main difference between a relay and a contactor? A. Contactors control current and relays control voltage. B. A relay is series connected and a contactor ... loads than relays. D. Contactors are made from silver and relays are made from copper.

Last Answer : Answer: C

Will rotor earth fault relay operate for earth fault in main exciter winding or RCU Diode Bridge also?

Description : Will rotor earth fault relay operate for earth fault in main exciter winding or RCU Diode Bridge also? 

Last Answer : Yes. 

Will main generator differential relay pick up for generator earth faults?

Description : Will main generator differential relay pick up for generator earth faults? 

Last Answer : No earth fault current limited to 5A, while differential setting is 10%. 

Main function of cutout relay in electrical circuit is A. To prevent the reversal of current flow from the battery when dynamo speed (engine speed) reduces. B. To restrict the maximum output at high speed. C. To permit the generation to deliver current to the battery or to the lightening and ignition circuit. D. None of the above

Description : Main function of cutout relay in electrical circuit is A. To prevent the reversal of current flow from the battery when dynamo speed (engine speed) reduces. B. To restrict the maximum output at ... deliver current to the battery or to the lightening and ignition circuit. D. None of the above

Last Answer : A. To prevent the reversal of current flow from the battery when dynamo speed (engine speed) reduces.

function of equipment’s used in sub-stations : (i) Earth Switch (ii) Relay (iii) Lighting Arrester (iv) Auxiliary transformer

Description : function of equipment’s used in sub-stations : (i) Earth Switch (ii) Relay (iii) Lighting Arrester (iv) Auxiliary transformer 

Last Answer : (i) Earth Switch   It's function is to discharge the ground capacitance when line is open circuited for maintenance purpose by isolator.) Earthing switch is inter - locked with isolator from the safety point ... 3-ph, 4wire, 400V) to give supply to control room, area lighting, staff quarters etc, 

Where mho relay used

Last Answer : Mho distance relays are widely used for the protection of uncompensated and series compensated transmission lines in order to determine the presence and location of faults.

Draw a neat labeled diagram to show protective system for AC traction and give the function of each relay used in it.

Description : Draw a neat labeled diagram to show protective system for AC traction and give the function of each relay used in it. 

Last Answer : Protective system for AC traction:  Function Of Each Relay: For transformer -  Inverse time over current relay- as back up protection on primary (HV side) over current ... against faults near substation  Under voltage relay - protection against faults far away from substation

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.

For a traction transformer circuit breaker state: 1) Rated current and rupturing capacity 2) Any two tests it should be capable of withstanding 3) Overall tripping time and relay time.

Description : For a traction transformer circuit breaker state: 1) Rated current and rupturing capacity 2) Any two tests it should be capable of withstanding 3) Overall tripping time and relay time.

Last Answer : Ans: 1) Rated current --- 750 A and Rupturing capacity --- 500 MVA  2) Any two tests it should be capable of withstanding --- Breaking test , Reclosing test , Endurance test ( any two )  3) Overall tripping time --- 0.14 sec and Relay time --- 0.04 sec 

Explain the construction and working of electronic overload relay.

Description : Explain the construction and working of electronic overload relay.

Last Answer : Electronic overload relay consists of a solid state circuit that operates the electromagnetic switching device to protect the load from overload. The load current is sensed by using a current ... sections. The output of relay driver section sends trip signal to electromagnetic switching device.