what is reverse power relay?

what is reverse power relay?
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1 Answer

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!
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Related questions

The device which allows reverse power flow and withstands highest switch frequency is

Description : The device which allows reverse power flow and withstands highest switch frequency is (A) GTO (B) MOSFET (C) IGBT (D) Inverter grade SCR

Last Answer : The device which allows reverse power flow and withstands highest switch frequency is MOSFET

Burden of a protective relay is the power?

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

What happens when you reverse the direction of the current in an electromagnet?

Description : What happens when you reverse the direction of the current in an electromagnet?

Last Answer : When  you  reverse  current  direction  in  an  electromagnet,  the magnetic  poles  will  also  change.

A diode in which the change in reverse bias voltage varies the capacitance is called as

Description : A diode in which the change in reverse bias voltage varies the capacitance is called as A) Varactor diode B) Switching diode C) Tunnel diode D) Zener-diode  

Last Answer : A diode in which the change in reverse bias voltage varies the capacitance is called as Varactor diode

How can we reverse the direction of rotation of synchronous motor?

Description : How can we reverse the direction of rotation of synchronous motor?

Last Answer : By reversing supply phase sequence we can reverse the direction of rotation of synchronous motor.

What is the difference between forward and reverse bias?

Description : What is the difference between forward and reverse bias?

Last Answer : Forward bias is a PN junction bias which allows current to flow through the junction. Forward bias decreases the resistance of the depletion layer. Reverse bias is a PN junction bias that allows only ... Positive polarity on the n-type material and negative polarity to the p-type material.

in which BJT operating region both the junctions are reverse biased?

Last Answer : In cut-off region of BJT both the emitter-base junction and collector-base junction are reverse biased.

main parts of Relay

Description : main parts of Relay

Last Answer : Coil, plunger, contacts, springs, connecting terminals and enclosure.

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

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.

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 .

according to ohms law voltage directly proportional to current but it is reverse in transformer why?

Description : About trnsformer

Last Answer : Acc to Ohms law V=IR but it is only applicable when our resistance R is constant, as in case of transformer we take impedence which is equivalent to resistance is not constant it varies with system parameters that why Ohms law not applicable in case of transformer

Briefly explain how the power factor of an inductive circuit can be improved.

Description : Briefly explain how the power factor of an inductive circuit can be improved.

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Why engine power is measured in horsepower (HP) ?

Description : Why engine power is measured in horsepower (HP) ?

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Why is AC better for long distance power transmission than DC ?

Description : Why is AC better for long distance power transmission than DC ?

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Why don't we burry power lines underground ?

Description : Why don't we burry power lines underground ?

Last Answer : Because conductor used for power transmission are not insulated and if we do so it create phase to ground fault causing interruptions to supply.

Why capacitors are used to improve power factor?

Description : Why capacitors are used to improve power factor?

Last Answer :  Capacitors generate reactive power instead of that drawn from source which is required by inductive loads.so it reduce the reactive current which is drawn from source to be drawn from capacitor.This control in Electric bills cost.

Draw the block diagram of satellite sub-system and explain power subsystem.

Description : Draw the block diagram of satellite sub-system and explain power subsystem.

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Classify condensers used in thermal power station. Explain each type in brief.

Description : Classify condensers used in thermal power station. Explain each type in brief. 

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State elements of diesel electric power plant with their functions.

Description : State elements of diesel electric power plant with their functions. 

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Explain the working of Hydro power station with schematic layout.

Description : Explain the working of Hydro power station with schematic layout. 

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