The under voltage relay can be used for?

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1 Answer

Answer :

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

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Related questions

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.

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 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 

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 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

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The operating time of instantaneous relay is

Description : The operating time of instantaneous relay is

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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.

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

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

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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

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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

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

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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.

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.

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.

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 .

List standard voltage level used in India.

Description : List standard voltage level used in India. 

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An unshielded moving iron voltmeter is used to measure the voltage in an AC circuit. The stray DC magnetic

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The frequencies and voltage used in Dielectric heating are

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The voltage used for suburban trains in D.C. system is usually?

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What equipment is used to measure voltage?

Description : What equipment is used to measure voltage?

Last Answer : Voltmeter is used to measure voltage.

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A Buchholz relay can be installed on?

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Over voltage protection is recommended for?

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The contacts of high voltage switches used in power system are submerged in oil. The main purpose of the oil is to?

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The arc voltage produced in A.C. circuit breaker is always?

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The voltage appearing across the contacts after opening of the circuit breaker is called______voltage.

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