If three AC generators are operating in parallel, and one of them were to 'pull out' of synchronism with the other two generators, the ____________. A. normally operating AC generators will vibrate severely B. AC generator pulling out of synchronism will vibrate severely C. normally operating AC generators will overspeed and unload D. AC generator pulling out of synchronism will become motorized

If three AC generators are operating in parallel, and one of them were to 'pull out' of synchronism with the other two generators, the ____________. A. normally operating AC generators will vibrate severely B. AC generator pulling out of synchronism will vibrate severely C. normally operating AC generators will overspeed and unload D. AC generator pulling out of synchronism will become motorized
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Answer: B
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Related questions

If a synchronous motor begins to vibrate severely and pull out of synchronism, the cause may be ____________. A. an overload B. an open in the field coils C. no exciter voltage D. all of the above

Description : If a synchronous motor begins to vibrate severely and pull out of synchronism, the cause may be ____________. A. an overload B. an open in the field coils C. no exciter voltage D. all of the above

Last Answer : Answer: D

An alternator operating in parallel begins to vibrate severely and eventually trips out on the reverse power relay. The cause of the vibration was a result of ______________________. A. the dropping of load by that alternator B. overspeeding of the vibrating alternator C. the alternator was operating out of synchronism D. flashover at the alternator collector rings

Description : An alternator operating in parallel begins to vibrate severely and eventually trips out on the reverse power relay. The cause of the vibration was a result of ______________________. A. the ... C. the alternator was operating out of synchronism D. flashover at the alternator collector rings

Last Answer : Answer: C

A loss of field excitation to an AC generator while operating in parallel will cause it to ____________. A. absorb more and more load due to decreased armature reaction B. lose its load due to the inherent speed droop built into the governor C. smoke and overload due to field flashover as residual field flux changes polarity D. lose its load, begin to motorize, trip out on reverse power relay, and possibly overspeed

Description : A loss of field excitation to an AC generator while operating in parallel will cause it to ____________. A. absorb more and more load due to decreased armature reaction B. lose its load due to ... polarity D. lose its load, begin to motorize, trip out on reverse power relay, and possibly overspeed

Last Answer : Answer: D

A generator is prevented from becoming motorized by the use of a/an _____________. A. overspeed trip B. reverse power relay C. back pressure trip D. governor controls

Description : A generator is prevented from becoming motorized by the use of a/an _____________. A. overspeed trip B. reverse power relay C. back pressure trip D. governor controls

Last Answer : Answer: B

An AC generator operating in parallel loses its excitation without tripping the circuit breaker. This will __________. A. not affect the faulty generator due to the compensation of the other generators B. cause the slip rings to melt C. cause a low voltage differential to develop between the armature and the bus D. cause high currents to be induced in the field windings

Description : An AC generator operating in parallel loses its excitation without tripping the circuit breaker. This will __________. A. not affect the faulty generator due to the compensation of the other generators B. ... between the armature and the bus D. cause high currents to be induced in the field windings

Last Answer : Answer: D

If field excitation is suddenly lost to an alternator operating in parallel, that alternator will _____________. A. supply excessive current to the bus B. operate at the same load, but with reduced voltage C. lose its load and tend to overspeed D. become overloaded and slow down

Description : If field excitation is suddenly lost to an alternator operating in parallel, that alternator will _____________. A. supply excessive current to the bus B. operate at the same load, but with reduced voltage C. lose its load and tend to overspeed D. become overloaded and slow down

Last Answer : Answer: C

When paralleling two AC generators, the frequency of the machine coming online, immediately prior to closing its breaker, should be ____________. A. slightly less than the oncoming generator frequency B. the same as the bus frequency C. slightly greater than the bus frequency D. the same as the bus voltage

Description : When paralleling two AC generators, the frequency of the machine coming online, immediately prior to closing its breaker, should be ____________. A. slightly less than the oncoming generator frequency B. the ... bus frequency C. slightly greater than the bus frequency D. the same as the bus voltage

Last Answer : Answer: C

Severe vibration, accompanied by flashover at the collector rings of an alternator operating in parallel, is a symptom of _____________. A. reverse current motorization B. loss of synchronism C. destructive overspeeding D. reversed polarity

Description : Severe vibration, accompanied by flashover at the collector rings of an alternator operating in parallel, is a symptom of _____________. A. reverse current motorization B. loss of synchronism C. destructive overspeeding D. reversed polarity

Last Answer : Answer: B

The power factor of an AC generator operating singularly is determined by the __________. A. connected load B. prime mover speed C. field excitation D. generator's rated voltage

Description : The power factor of an AC generator operating singularly is determined by the __________. A. connected load B. prime mover speed C. field excitation D. generator's rated voltage

Last Answer : Answer: A

Two AC generators of the same capacity are operating in parallel. One with a zero speed droop setting and the other with a 5% speed droop. If its capacity is not exceeded, the unit whose governor has the zero speed droop setting will _____________. A. assume the smaller share of the load B. maintain the frequency of the system C. have poor sensitivity characteristics D. have poor power response

Description : Two AC generators of the same capacity are operating in parallel. One with a zero speed droop setting and the other with a 5% speed droop. If its capacity is not exceeded, the unit whose ... B. maintain the frequency of the system C. have poor sensitivity characteristics D. have poor power response

Last Answer : Answer: B

The load sharing characteristics of two diesel generators operating in parallel are mostly dependent on their governor ____________. A. load limit settings B. idle speed settings C. speed limit settings D. speed droop settings

Description : The load sharing characteristics of two diesel generators operating in parallel are mostly dependent on their governor ____________. A. load limit settings B. idle speed settings C. speed limit settings D. speed droop settings

Last Answer : Answer: D

If the energy input is significantly reduced to the prime mover of one shipboard alternator operating in parallel with others, that alternator will _____________. A. continue to operate at no load B. lose its load and overspeed C. begin to motorize and then trip out D. slow down and operate at reduced load

Description : If the energy input is significantly reduced to the prime mover of one shipboard alternator operating in parallel with others, that alternator will _____________. A. continue to operate at no load B. lose ... overspeed C. begin to motorize and then trip out D. slow down and operate at reduced load

Last Answer : Answer: C

Diesel generators #1 and #2 are operating in parallel at near full load capacity. Diesel generator #1 suddenly trips out mechanically due to low lube oil pressure. The reverse power relay functions properly and trips generator #1 electrically off the bo A. Start the emergency generator. B. Ascertain cause of the low lube oil pressure. C. Strip the board of all nonvital circuits. D. Secure alarms, reset reverse power relay, and restart #1 engine.

Description : Diesel generators #1 and #2 are operating in parallel at near full load capacity. Diesel generator #1 suddenly trips out mechanically due to low lube oil pressure. The reverse power relay functions ... all nonvital circuits. D. Secure alarms, reset reverse power relay, and restart #1 engine.

Last Answer : Answer: C

Which is a function of the voltage regulators used with AC generators? A. To cut out generators when they are no longer required. B. To cut in additional generators automatically as required. C. To divide the KW load equally between generators operating in parallel. D. To divide reactive current between generators operating in parallel.

Description : Which is a function of the voltage regulators used with AC generators? A. To cut out generators when they are no longer required. B. To cut in additional generators automatically as ... between generators operating in parallel. D. To divide reactive current between generators operating in parallel.

Last Answer : Answer: D

The division of the kilowatt load between two AC generators operating in parallel is controlled by the settings and characteristics of the _____________. A. voltage regulators B. field rheostats C. reverse power relays D. prime mover governors

Description : The division of the kilowatt load between two AC generators operating in parallel is controlled by the settings and characteristics of the _____________. A. voltage regulators B. field rheostats C. reverse power relays D. prime mover governors

Last Answer : Answer: D

Kilowatt load is divided between two AC generators operating in parallel by _____________. A. adjusting the governor controls B. varying the excitation voltage C. increasing both prime mover speeds simultaneously D. decreasing both prime mover speeds simultaneously

Description : Kilowatt load is divided between two AC generators operating in parallel by _____________. A. adjusting the governor controls B. varying the excitation voltage C. increasing both prime mover speeds simultaneously D. decreasing both prime mover speeds simultaneously

Last Answer : Answer: A

To increase the frequency of an operating AC generator, you should ____________. A. increase the field excitation B. decrease the field excitation C. increase the number of magnetic poles D. increase the speed of the prime mover

Description : To increase the frequency of an operating AC generator, you should ____________. A. increase the field excitation B. decrease the field excitation C. increase the number of magnetic poles D. increase the speed of the prime mover

Last Answer : Answer: D

Undervoltage trips are frequently installed on switchboard circuit breakers to trip ____________. A. out generators in the event of severe arcing or sparking B. out generators when there is reversal of power in the main circuit C. the breaker if the generator overspeeds by 5%, but continues to run D. out generators when there is low voltage in the main circuit

Description : Undervoltage trips are frequently installed on switchboard circuit breakers to trip ____________. A. out generators in the event of severe arcing or sparking B. out generators when there is reversal of power ... , but continues to run D. out generators when there is low voltage in the main circuit

Last Answer : Answer: D

When paralleling two AC generators, the frequency of the incoming machine immediately prior to closing its breaker should be ____________. A. controlled by placing the governor switch in the automatic position B. adjusted with the voltage regulator C. slightly greater than the bus frequency D. slightly less than the bus frequency

Description : When paralleling two AC generators, the frequency of the incoming machine immediately prior to closing its breaker should be ____________. A. controlled by placing the governor switch in the automatic ... regulator C. slightly greater than the bus frequency D. slightly less than the bus frequency

Last Answer : Answer: C

When two AC generators are being paralleled, the breaker should be closed with the synchroscope pointer rotating in the ____________. A. 'slow' direction, just before the 12 o'clock position B. 'fast' direction, just after the 12 o'clock position C. 'fast' direction, just before the 12 o'clock position D. 'slow' direction, just after the 12 o'clock position

Description : When two AC generators are being paralleled, the breaker should be closed with the synchroscope pointer rotating in the ____________. A. 'slow' direction, just before the 12 o'clock position B. 'fast' ... just before the 12 o'clock position D. 'slow' direction, just after the 12 o'clock position

Last Answer : Answer: C

While paralleling two (2) AC generators using synchronizing lamps only, both lamps will go dark when the generators are ____________. A. running at the same speed B. grounded C. of the same polarity D. in phase

Description : While paralleling two (2) AC generators using synchronizing lamps only, both lamps will go dark when the generators are ____________. A. running at the same speed B. grounded C. of the same polarity D. in phase

Last Answer : Answer: D

Voltage generated by most AC generators is fed from the machine to the bus by means of ____________. A. brushes on a commutator B. brushes on slip rings C. slip rings on a commutator D. direct connections from the stator

Description : Voltage generated by most AC generators is fed from the machine to the bus by means of ____________. A. brushes on a commutator B. brushes on slip rings C. slip rings on a commutator D. direct connections from the stator

Last Answer : Answer: D

You are attempting to parallel two AC generators and the synchroscope pointer stops at a position other than 0°. If you close the circuit breaker at this moment _____________. A. the incoming machine will accept all of the load B. the incoming machine will trip out on low voltage release C. a hazardous condition will be created by the cross current between the machines D. a hazardous condition will be created by the incoming machine being at a higher frequency than the bus

Description : You are attempting to parallel two AC generators and the synchroscope pointer stops at a position other than 0°. If you close the circuit breaker at this moment _____________. A. the incoming ... hazardous condition will be created by the incoming machine being at a higher frequency than the bus

Last Answer : Answer: C

When paralleling two AC generators, the frequency (cycles) of the incoming generator, just prior to closing the circuit breaker, should be _____________. A. slightly less than the frequency of the generator on the line B. the same as the frequency of the generator on the line C. slightly more than the frequency of the generator on the line D. all of the above

Description : When paralleling two AC generators, the frequency (cycles) of the incoming generator, just prior to closing the circuit breaker, should be _____________. A. slightly less than the frequency of the generator on ... C. slightly more than the frequency of the generator on the line D. all of the above

Last Answer : Answer: C

When paralleling two AC generators, the synchroscope selector switch and frequency meter switch should be set up to sense the frequency of the _____________. A. bus B. generator on the line C. oncoming generator D. bus transfer relay

Description : When paralleling two AC generators, the synchroscope selector switch and frequency meter switch should be set up to sense the frequency of the _____________. A. bus B. generator on the line C. oncoming generator D. bus transfer relay

Last Answer : Answer: C

Automatic voltage regulators provided on switchboards function to _____________. A. regulate the AC load on the generator B. protect the switchboard from high voltage C. govern prime mover speed to control voltage D. vary the field excitation to the generators

Description : Automatic voltage regulators provided on switchboards function to _____________. A. regulate the AC load on the generator B. protect the switchboard from high voltage C. govern prime mover speed to control voltage D. vary the field excitation to the generators

Last Answer : Answer: D

Why is it desirable to operate paralleled AC generators at the same power factor? A. Circulating currents are kept to a minimum. B. Field excitation losses are kept to a minimum. C. Generator rotors will have a lesser tendency to hunt. D. Because a power factor increase will decrease kilowatt output.

Description : Why is it desirable to operate paralleled AC generators at the same power factor? A. Circulating currents are kept to a minimum. B. Field excitation losses are kept to a minimum. C. Generator ... will have a lesser tendency to hunt. D. Because a power factor increase will decrease kilowatt output.

Last Answer : Answer: A

The power factor at which a paralleled AC generator operates is usually adjusted by the _____________. A. connected load B. prime mover speed C. field excitation D. generator's rated voltage

Description : The power factor at which a paralleled AC generator operates is usually adjusted by the _____________. A. connected load B. prime mover speed C. field excitation D. generator's rated voltage

Last Answer : Answer: C

You are attempting to parallel two AC generators and the synchroscope pointer stops at a position other than 0° prior to closing the circuit breaker. This indicates ___________. A. the frequency of the incoming machine is the same as the bus frequency B. the incoming machine is in phase with the bus, but the frequency is not the same C. the circuit breaker may be closed after breaker has been reset D. there is an existing cross current between generators

Description : You are attempting to parallel two AC generators and the synchroscope pointer stops at a position other than 0° prior to closing the circuit breaker. This indicates ___________. A. the frequency of ... be closed after breaker has been reset D. there is an existing cross current between generators

Last Answer : Answer: A

The timer element of a reverse power relay cannot be energized unless _____________. A. the power flow is the same as the tripping direction B. the power flow is the opposite to the tripping direction C. the movement of the disk is damped by a permanent magnet D. one generator is motorized

Description : The timer element of a reverse power relay cannot be energized unless _____________. A. the power flow is the same as the tripping direction B. the power flow is the opposite to the tripping direction C. the movement of the disk is damped by a permanent magnet D. one generator is motorized

Last Answer : Answer: A

The timer element of a reverse power relay cannot be energized unless _____________. A. one generator is fully motorized B. the movement of the disk is damped by a permanent magnet C. the power flow is the same as the tripping direction D. the power flow is the opposite to the tripping direction

Description : The timer element of a reverse power relay cannot be energized unless _____________. A. one generator is fully motorized B. the movement of the disk is damped by a permanent magnet C. the power flow is the same as the tripping direction D. the power flow is the opposite to the tripping direction

Last Answer : Answer: C

Three factors responsible for the change in voltage as load is applied to an AC generator are: 1) the drop in resistance in the armature circuit, 2) the change in flux, and 3) the ____________. A. armature winding speed B. inductance load drop C. coil pitch factor D. armature reactance voltage drop

Description : Three factors responsible for the change in voltage as load is applied to an AC generator are: 1) the drop in resistance in the armature circuit, 2) the change in flux, and 3) the ____________. A. armature winding speed B. inductance load drop C. coil pitch factor D. armature reactance voltage drop

Last Answer : Answer: D

On electrical generators one of the bearings is isolated from the bedplate. This insulating block should not be painted and must be kept clean to ___________. A. protect operating personnel from shock B. create an isolated ground for the instrumentation C. allow for the expansion of the generator away from the prime mover as it warms up D. eliminate shaft currents to prevent damaging the bearings

Description : On electrical generators one of the bearings is isolated from the bedplate. This insulating block should not be painted and must be kept clean to ___________. A. protect operating personnel from shock ... the prime mover as it warms up D. eliminate shaft currents to prevent damaging the bearings

Last Answer : Answer: D

The maximum constant load torque under which a synchronous motor will pull into synchronism...

Description : The maximum constant load torque under which a synchronous motor will pull into synchronism at rated rotor supply voltage and frequency is known as?

Last Answer : The maximum constant load torque under which a synchronous motor will pull into synchronism at rated rotor supply voltage and frequency is known as pull-in torque.

A vessel is equipped with two ship's service generators. Generator #1 is rated at 900 kw and generator #2 is rated at 600 kw. During parallel operation, with a hotel load of 1,000 kw, what should be the kw load on generator #2? A. 100 kw B. 400 kw C. 500 kw D. 600 kw

Description : A vessel is equipped with two ship's service generators. Generator #1 is rated at 900 kw and generator #2 is rated at 600 kw. During parallel operation, with a hotel load of 1,000 kw, what should be the kw load on generator #2? A. 100 kw B. 400 kw C. 500 kw D. 600 kw

Last Answer : Answer: B

An equalizing connection between two compound-wound DC generators when paralleled, serves to _____________. A. reverse the polarity of the incoming generator as the series field weakens B. automatically equalize the power factors C. reverse the direction of current in the series field of the incoming generator D. parallel the series fields of the generators

Description : An equalizing connection between two compound-wound DC generators when paralleled, serves to _____________. A. reverse the polarity of the incoming generator as the series field weakens B. automatically ... the series field of the incoming generator D. parallel the series fields of the generators

Last Answer : Answer: D

In the illustration, the contacts between terminals 26 and 27 should be closed when _________. EL-0046 A. using one generator in isochronous mode only B. using two or more generators in parallel only C. the prime mover speed is to remain constant through varying loads in parallel or single operation D. the circuit breaker is closed for that generator

Description : In the illustration, the contacts between terminals 26 and 27 should be closed when _________. EL-0046 A. using one generator in isochronous mode only B. using two or more generators in ... through varying loads in parallel or single operation D. the circuit breaker is closed for that generator

Last Answer : Answer: C

The removal of paint from electrical equipment, such as generators, should be cautiously undertaken because ____________. A. the mechanical shock of paint removal lessens the dielectric strength of the insulation B. the paint dust is composed of abrasive and semi-conducting materials which impair insulation C. paint dust buildup has a tendency to cause corrosion D. phase windings frequently become isolated from each other due to dust interference at the terminals

Description : The removal of paint from electrical equipment, such as generators, should be cautiously undertaken because ____________. A. the mechanical shock of paint removal lessens the dielectric strength ... phase windings frequently become isolated from each other due to dust interference at the terminals

Last Answer : Answer: B

Induction generator a) can not work in isolation b) can work in isolation c) should work in parallel with synchronous generators d) any of the mentioned

Description : Induction generator a) can not work in isolation b) can work in isolation c) should work in parallel with synchronous generators d) any of the mentioned

Last Answer : Ans: C

You are attempting to parallel two AC generators, and the synchroscope pointer is revolving fast in the clockwise direction. This indicates that the frequency of the incoming machine is _____________. A. higher than the bus frequency B. lower than the bus frequency C. the same as the bus frequency and the circuit breaker may be closed at any pointer position D. the same as the bus frequency but out of phase with it

Description : You are attempting to parallel two AC generators, and the synchroscope pointer is revolving fast in the clockwise direction. This indicates that the frequency of the incoming machine is _____________. A. higher ... at any pointer position D. the same as the bus frequency but out of phase with it

Last Answer : Answer: A

You are attempting to parallel two AC generators, and the synchroscope pointer is revolving in the fast direction. This indicates that the frequency of the incoming machine is _____________. A. higher than the bus frequency B. lower than the bus frequency C. the same as the bus frequency but out of phase with it D. the same as the bus frequency and the circuit breaker may be closed at any pointer position

Description : You are attempting to parallel two AC generators, and the synchroscope pointer is revolving in the fast direction. This indicates that the frequency of the incoming machine is _____________. A. higher ... the same as the bus frequency and the circuit breaker may be closed at any pointer position

Last Answer : Answer: A

You are attempting to parallel two AC generators and the synchroscope pointer is revolving in the slow direction. This indicates that the frequency of the incoming machine is _____________. A. higher than the bus frequency B. lower than the bus frequency C. the same as the bus frequency but out of phase with it D. the same as the bus frequency, and the circuit breaker may be closed at any pointer position

Description : You are attempting to parallel two AC generators and the synchroscope pointer is revolving in the slow direction. This indicates that the frequency of the incoming machine is _____________. A. higher than ... same as the bus frequency, and the circuit breaker may be closed at any pointer position

Last Answer : Answer: B

If two AC generators have just been placed in parallel, the true power load is initially distributed evenly by _____________. A. a balance coil B. changing field excitation C. adjusting the governor control settings D. a rheostat

Description : If two AC generators have just been placed in parallel, the true power load is initially distributed evenly by _____________. A. a balance coil B. changing field excitation C. adjusting the governor control settings D. a rheostat

Last Answer : Answer: C

Which of the methods listed is used to maintain the division of load between two compound-wound, DC generators operating in parallel? A. The shunt fields are interconnected. B. The shunt field rheostats are interconnected. C. The series fields of both generators are connected in series. D. The equalizer connection parallels the series fields of all machines.

Description : Which of the methods listed is used to maintain the division of load between two compound-wound, DC generators operating in parallel? A. The shunt fields are interconnected. B. The shunt ... generators are connected in series. D. The equalizer connection parallels the series fields of all machines.

Last Answer : Answer: D

When two generators are on the line and are sharing the load equally, they are said to be operating in _____________. A. frequency B. series C. parallel D. resonance

Description : When two generators are on the line and are sharing the load equally, they are said to be operating in _____________. A. frequency B. series C. parallel D. resonance

Last Answer : Answer: C

Which of the methods listed is used to maintain equal load sharing between two compound wound DC generators operating in parallel? A. The shunt fields are interconnected. B. The shunt field rheostats are interconnected. C. The series fields of both generators are connected in series. D. The series fields of both generators are connected in parallel.

Description : Which of the methods listed is used to maintain equal load sharing between two compound wound DC generators operating in parallel? A. The shunt fields are interconnected. B. The shunt field rheostats ... are connected in series. D. The series fields of both generators are connected in parallel.

Last Answer : Answer: D

List the factors that affect the load sharing in parallel operating generators?

Description : List the factors that affect the load sharing in parallel operating generators?

Last Answer : The total active and reactive power delivered to the load, connected across the common bus-bars, are shared among Synchronous generators, operating in parallel, based on the following three factors ... characteristic/input · Excitation level and · Percentage synchronous impedance and its R/X ratio