# Interruption of large currents by relay requires?

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

## Related Questions

What is voltage interruption?

Explain following techniques related to energy conservation in transmission and distribution system. (i) By balancing phase currents (ii) Variable technical losses (I2R losses).
Last Answer : (i) Balancing Phase currents: Proper (healthy balanced) three phase loads always draw equal currents in all lines but single phase loads in the 3 phase 4 wire system or loads connected between two ... . 11) Minimize I2R losses. 12) Balance the load currents. 13) Regulate the system voltages.

The transient currents are associated with the?
Last Answer : The transient currents are associated with the changes in the stored energy in the inductors and capacitors.

Last Answer : In a single phase power factor meter the phase difference between the currents in the two pressure coils is exactly 90°.

Last Answer : For handling greater currents induction wattmeters are used in conjunction with current transformers.

Eddy currents are induced in the pole shoes of a D.C. machine due to?
Last Answer : Eddy currents are induced in the pole shoes of a D.C. machine due to relative rotation between field and armature.

How eddy currents are generated?

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.

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

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

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  (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  (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 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
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 (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 (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

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

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

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

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

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

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.

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

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

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.

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 ?
Last Answer : Relay working like contact it is noise less

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?
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 .

Interruption of large currents by relay requires (a) arc suppressing blow out coils (b) wide separation of the opened contacts (c) high speed opening of contacts (d) all of the above
Last Answer : (d) all of the above

How to Shrink Large Pores
Last Answer : How to Shrink Large Pores Large pores can be a hassle, especially in a world full of airbrushed models with no visible pores filling our magazine pages. Large pores can also lead to a tendency ... add calamine or sandalwood powder to the tomato juice before applying. Rinse it off with warm water.

A large AC generator, supplying power to an infinite bus, has a sudden short-circuit occurring at its terminals. Assuming the prime mover input and the voltage behind the transient reactance to remain constant immediately after the fault, acceleration of the generator rotor is
Last Answer : A large AC generator, supplying power to an infinite bus, has a sudden short-circuit occurring at its terminals. Assuming the prime mover input and the voltage behind the transient reactance ... , acceleration of the generator rotor is inversely proportional to the moment of inertia of the machine

Last Answer : A sensitive galvanometer produces large deflection for a small value of current.

Last Answer : Large capacity generators are invariably hydrogen cooled.

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.

main parts of Relay
Last Answer : Coil, plunger, contacts, springs, connecting terminals and enclosure.

What is phase failure relay and how it's work?

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

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

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

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

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!

Calculate the current if 12 coulombs of charge passes through a wire at a steady rate in 35 seconds

The current zero interruption, in oil and air blast circuit breakers, is achieved by?
Last Answer : The current zero interruption, in oil and air blast circuit breakers, is achieved by lengthening of the gap, cooling and blast effect.

A differential relay measures the vector difference between (a) two currents (b) two voltages (c) two or more similar electrical quantities (d) none of the above
Last Answer : (c) two or more similar electrical quantities

With the help of neat diagram, explain operation of static relay.
Last Answer : Operation of Static Relay: Operation: 1) The solid-state component used are transistors, diodes, resistors, IC s, capacitor etc. The function of comparison and measurement are accomplished by ... ) An auxiliary dc supply is provided for operation of static relay elements as shown in figure.