A negative sequence relay is commonly used to protect

A negative sequence relay is commonly used to protect 

(A) an alternator (B) an transformer (C) a transmission line (D) a bus bar
by

1 Answer

Answer :

A negative sequence relay is commonly used to protect  an alternator

by

Related questions

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 transmission line distance protection relay having the property of being inherently directional is

Description : The transmission line distance protection relay having the property of being inherently directional is (A) impedance relay (B) MHO relay (C) OHM relay (D) reactance relay

Last Answer : The transmission line distance protection relay having the property of being inherently directional is MHO relay

If the fault current is 2000 A, the relay setting is 50% and CT ratio is 400:5, the plug setting multiplier will be

Description : If the fault current is 2000 A, the relay setting is 50% and CT ratio is 400:5, the plug setting multiplier will be

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A reactance relay is

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

What is the time of operation of a relay of rating 5 amp 2.2 sec, ...

Description : What is the time of operation of a relay of rating 5 amp 2.2 sec, IDMT and having a relay of setting of 125% Tms = 0.6 It is connected to a supply circuit through a CT, 400 ratio. The fault current is 400 amp.

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A power system is subjected to a fault which makes the zero sequence component of current equal to zero

Description :  A power system is subjected to a fault which makes the zero sequence component of current equal to zero. The nature of fault current is: A) Double line to ground fault B) Line to line fault C) Line to ground fault D) Three-phase to ground fault

Last Answer :  A power system is subjected to a fault which makes the zero sequence component of current equal to zero. The nature of fault current is: Line to line fault

The zero sequence current of a generator for line to ground fault is j 2.4 p.u. The current through the neutral

Description : The zero sequence current of a generator for line to ground fault is j 2.4 p.u. The current through the neutral during the fault is (a) j 0.8 p.u (b) j 2.4 p.u. (c) j 0.24 p.u. (d) j 7.2 p.u. 

Last Answer : j7.2

The sequence components of current of a single-phase load connected to a 3-phase system are

Description : The sequence components of current of a single-phase load connected to a 3-phase system are (A) equal positive and negative sequence components (B) equal positive, negative and zero sequence components (C) vector sum of sequence currents is zero (D) algebraic sum of sequence currents is zero

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An alternator has a phase sequence of RYB for its phase voltage. In case...

Description : An alternator has a phase sequence of RYB for its phase voltage. In case the direction of rotation of alternator is reversed, the phase sequence will become?

Last Answer : An alternator has a phase sequence of RYB for its phase voltage. In case the direction of rotation of alternator is reversed, the phase sequence will become RBY.

A transformer has negative voltage regulation when its load power factor is

Description : A transformer has negative voltage regulation when its load power factor is   (1) Zero (2) Unity (3) Leading (4) Lagging

Last Answer : 0

Which organization in the United States studies and assesses the environment to protect it and the people affected by any negative change in the environment?

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Which of the following is correct for CD8 T cells? A- CD8 T cells only recognize virus-infected cells B- CD8 T cell receptor recognizes epitopes that are also commonly recognized by B cells C- In the thymus, CD8 T cells undergo positive selection only, whereas CD4 T cells undergo negative selection only D- CD8 T cells can kill individual virus-infected cells in a contact dependent fashion

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Define negative sequence component.

Description : Define negative sequence component.

Last Answer : It has 3 vectors equal in magnitude and displaced from each other by an angle 120 degrees and has the phase sequence in opposite to its original phasors.

What is meant by positive, negative and zero sequence reactance.

Description : What is meant by positive, negative and zero sequence reactance.

Last Answer : The reactance diagram of a power system, when formed using positive, negative and zero sequence reactances are called positive, negative and zero sequence reactance diagram resp.

What is meant by positive, negative and zero sequence impedance.

Description : What is meant by positive, negative and zero sequence impedance.

Last Answer : The impedance of the circuit element for positive, negative and zero sequence component currents are called positive, negative and zero sequence impedances resp.

What are negative sequence components?

Description : What are negative sequence components?

Last Answer : The negative sequence components of a three phase unbalanced vectors consists of three vectors of equal magnitude displaced from each other by 120 degree in phase and having the phase sequence opposite to that of the original vectors.

When the negative sequence reactance arises?

Description : When the negative sequence reactance arises?

Last Answer : Negative sequence arises whenever there is any unbalance present in the system. Their effect is to set up a field rotating in opposite direction to the main field.

What is Negative sequence reactance?

Description : What is Negative sequence reactance?

Last Answer : Negative sequence can arise whenever there is any unbalance present in the system. Their effect is to setup a field rotating in opposite direction to the main field. 

What you mean by positive sequence, negative sequence and zero sequence of voltage?

Description : What you mean by positive sequence, negative sequence and zero sequence of voltage?

Last Answer : Positive phase sequence A system of vectors is said to have positive sequence if they are all of equal magnitude and are displaced by 120° with same time interval to arrive at fixed axis of reference ... in all the 3- phases. Such phase sequence is zero phase sequence.

What is the negative sequence capability?

Description : What is the negative sequence capability?

Last Answer : I2 = 5% max,  I2 2 t = 7

Va and Vb are negative sequence component voltages the difference angle between Va and Vb with respect to Va is a) 240 b) 120 c) 180 d) 360

Description : Va and Vb are negative sequence component voltages the difference angle between Va and Vb with respect to Va is a) 240 b) 120 c) 180 d) 360

Last Answer : Ans: 120

For which of the following protection from negative sequence currents is provided ? (a) Generators (b) Motors (c) Transmission line (d) Transformers

Description : For which of the following protection from negative sequence currents is provided ? (a) Generators (b) Motors (c) Transmission line (d) Transformers

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Explain negative phase sequence protection of alternator.

Description : Explain negative phase sequence protection of alternator.

Last Answer : Negative phase sequence protection of alternator: Unbalanced loading on alternator mainly causes the negative sequence currents which generate the negative sequence components of magnetic fields. These fields ... components due to unbalance and operates the relay which further operates CB.

Systems for Protection from negative sequence current is provided normally for

Description : Systems for Protection from negative sequence current is provided normally for (a) Transformers (c) Transmission lines (b) Generators (d) Motors

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