Description : Equal power factors on paralleled AC generators are maintained by an automatic _____________. A. voltage regulator B. reverse power relay C. reverse current relay D. governor control switch
Last Answer : Answer: A
Description : The voltage output of an AC generator is accurately controlled by _____________. A. changing the sensitivity of the prime mover to large changes in voltage B. varying the reluctance of the air gap C. varying the DC exciter voltage D. shorting out part of the armature windings
Last Answer : Answer: C
Description : The output voltage of a 440 volt, 60 hertz, AC generator is controlled by the _____________. A. prime mover speed B. exciter output voltage C. load on the alternator D. number of poles
Last Answer : Answer: B
Description : The output voltage of a 440 volt, 60 Hz AC generator is controlled by the ______________. A. load on the alternator B. load on the prime mover C. speed of the prime mover D. exciter output voltage
Last Answer : Answer: D
Description : The frequency of an AC generator is adjusted by means of the ____________. A. main alternator field rheostat B. exciter field rheostat C. prime mover governor control D. equalizing reactor
Description : Voltage failure of an AC generator may be caused by ____________. A. failure of the exciter generator B. a tripped bus circuit breaker C. high mica segments on the stator bus bar D. excessive prime mover speed
Description : A reverse-current relay will prevent AC generator motorization by ____________. A. automatically redirecting the load B. automatically speeding up the prime mover C. tripping the panel board main switch D. tripping the generator circuit breaker
Description : The voltage developed by an AC generator is controlled by varying the ____________. A. speed of the prime mover B. AC excitation to the field C. DC excitation to the field D. DC excitation of the voltage regulator
Description : Prior to starting an AC generator prime mover, the voltage regulator cutout switch should be placed in the __________. A. manual position B. bus neutral position C. raise voltage position D. transfer position
Description : Regarding an AC generator connected to the main electrical bus; as the electric load and power factor vary, a corresponding change is reflected in the generator armature reaction. These changes in ... . governor speed droop setting B. voltage regulator C. balance coil D. phase-balance relay
Description : The voltage of an operating AC turbogenerator is raised or lowered by adjusting the _____________. A. exciter generator governor controls B. synchronizing switch C. phase sequence switch D. generator field exciter
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
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
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
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
Description : The simplest method of controlling the terminal voltage of compound-wound DC generator is with a _____________. A. hand-operated field rheostat connected in series with the shunt field circuit B. ... in series with the load D. balance coil diverting neutral current through the shunt field
Description : The frequency of an AC generator is controlled by the _____________. A. rheostat B. governor C. exciter D. capacitor
Description : The standard method of controlling the output voltage of a 440 volt, 60 Hz, AC generator is accomplished by adjusting the ____________. A. prime mover speed droop B. number of poles C. alternator field excitation D. load on the alternator
Description : In the illustrated electronic governor, the circuit card connected to the potential and current transformers is for ________. EL-0046 A. increasing the signal strength to the governor to ... from motorization D. conditioning the load through the use of a magnetic amplifier current transformer
Description : As load is added to an AC generator provided with constant field excitation, the prime mover slows down with the effect of ____________. A. lowering frequency and lowering generated ... C. increasing frequency and lowering generated voltage D. lowering frequency and increasing generated voltage
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
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
Description : In an AC synchronous motor electric propulsion plant, propeller speed is controlled by varying the _____________. A. prime mover speed B. electric coupling field strength C. number of energized main motor poles D. propulsion generator field strength
Description : The division of the reactive KVA load between paralleled AC generators is initiated by the ______________. A. prime mover governors B. voltage regulators C. phase balance relay D. proportioner
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
Description : The most common source of excitation for synchronous motors is a/an _____________. A. low voltage battery B. motor attenuator set C. DC exciter generator D. AC supply
Description : A DC generator is used to supply direct current in order to maintain an AC generator field and is known as a/an _____________. A. rotor B. stator C. exciter D. armature
Description : A megger is being used to test the insulation of an AC generator. The resistance value of a dry, clean winding will _____________. A. continue to rise as test potential is maintained, ... , becoming fairly steady after 5-7 minutes D. stabilize after approximately 2-4 minutes of fluctuation
Description : An alternator will fail to produce line voltage as a result of _____________. A. a closed circuit breaker B. oxidized slip rings C. improperly staggered brushes D. exciter generator failure
Description : The prime mover of an AC two pole main propulsion generator drives the generator at 3600 RPM. If the main propulsion motor has 80 poles, what will be the propeller speed? A. 45 RPM B. 80 RPM C. 90 RPM D. 180 RPM
Description : Which of the methods listed is used to start a AC generator turning? A. Residual magnetism remaining in the field poles. B. Residual magnetism remaining in the field coils. C. Residual magnetism remaining in the armature. D. Rotation by a mechanical 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
Description : Silicon diodes designed for a specific reverse breakdown voltage, become useful as an electronic power supply voltage regulator, called _____________. A. tunnel diodes B. hot-carrier diodes C. compensating diodes D. Zener diodes
Description : In order to safely carry out repairs to a generator circuit breaker, it must be isolated from the bus. This is accomplished by opening the _____________. A. reverse power relay B. bus disconnect link C. generator bus fuse connections D. power directional relay
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
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
Description : If the bearings of an electrical generator are failing more frequently than expected and the lubricating oil is sludging then you should ______________. A. check the connections to the output leads B. ... replace the bearing with a sealed roller type D. replace the thrust bearing of the prime mover
Description : The most practical way to control the voltage output of an AC generator is to vary the _____________. A. number of windings B. speed of the rotating field C. strength of the rotating magnetic field D. power factor of the load
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
Description : The frequency of an alternator is controlled from the main switchboard by adjusting the _____________. A. frequency meter B. voltage regulator C. governor control D. sychroscope switch
Description : In the illustration, the component labeled 'EXC' is _______. EL-0003 A. a separate class II regulated DC generator for critical direct current loads B. a generator feeding the FLD ... to drive the governor for turbogenerator speed. D. the electronic driver for the switchboard metering circuits
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
Description : A switchboard for an AC electrical system requires the use of which of the following devices? A. Frequency meter. B. Ohmmeter. C. Induction voltage regulator. D. Current transformer governor.
Description : The timer element found in a reverse power relay obtains its operating torque via _____________. A. line voltage B. the main bus C. electromagnets D. a separate battery source
Description : The operating torque of the upper induction disc-type element, or timer element, of an AC reverse power relay is obtained from ____________. A. the main bus B. a separate battery source C. line voltage D. electromagnets
Description : When securing an AC generator, you should FIRST ___________. A. open the generator circuit breaker B. switch the voltage regulator to 'manual' C. decrease the field excitation to minimum D. reduce the load on the unit
Description : The instantaneous reduction in voltage of an AC generator, resulting from an increase in load, and prior to the automatic voltage regulator correcting the situation, is called voltage ____________. A. droop B. drop C. dip D. regulation
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
Description : Equalization of the power factors of two alternators operating in parallel is accomplished _____________. A. manually, by adjusting the governor controls B. automatically, by automatic voltage regulators ... the output of current transformers D. automatically, by the designed action of the governors
Description : You are testing the insulation in an AC generator with a megohmeter. The resistance value of a dry, clean winding will ____________. A. continue to rise as the test potential is maintained, ... fairly steady after 5 to 7 minutes D. stabilize after approximately 2 to 4 minutes of fluctuation