Description : When the operating handle of a molded case circuit breaker is in the mid-position, it indicates the circuit breaker is _____________. A. in the 'opened' position B. in the 'closed' position C. tripped D. reset
Last Answer : Answer: C
Description : When the operating handle of a molded-case circuit breaker is in the mid-position, this indicates that the circuit breaker is _____________. A. on B. off C. reset D. tripped
Last Answer : Answer: D
Description : How will a molded-case circuit breaker react after it has tripped, as a result of an overloaded circuit? A. The breaker will trip again if immediately reset. B. The breaker handle will lock in ... down. D. The breaker handle cannot be moved to the OFF position until the thermal element cools down.
Last Answer : Answer: A
Description : You can determine if a circuit breaker is tripped by ______. A. examining the position of the handle B. checking for the warm breaker C. looking for a burned-out link D. looking for the tripped breaker light
Description : You can determine if a circuit breaker has tripped by ________________. A. examining the position of the handle B. checking for which of the breakers is warm C. looking for a burned-out link D. all of the above
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 molded-case breaker provides protection against short circuits by using a/an ____________. A. shading coil B. arc quencher C. electromagnet D. holding coil
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
Description : When the operating handle is in the 'off' position, which master switch contacts for the winch shown in the illustration are closed? EL-0102 A. 'MS-DB & OL' B. 'MS-3, 5, 6, 7, & 8' C. 'MS-LVa & OL' D. 'MS-3, 7 & Reset'
Description : A molded-case circuit breaker provides protection against short circuits by using a/an ________________. A. electromagnet B. shading coil C. arc quencher D. burn away strip
Description : You are paralleling two alternators. The synchronizing lamps grow dim and are totally darkened as the synchroscope pointer approaches the 0° position. This indicates that the ____________. A. alternator ... be closed C. incoming alternator is running too slowly D. synchroscope is defective or broken
Last Answer : Answer: B
Description : A circuit breaker differs from a fuse in that a circuit breaker _____________. A. melts and must be replaced B. is enclosed in a tube of insulating material with metal ferrules at each end C. gives no visual indication of having opened the circuit D. trips to break the circuit and may be reset
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
Description : When replacing component 'B' of the circuit shown in the illustration, it is important to know that ____________. EL-0081 A. it is polarity sensitive and must be inserted as indicated on its ... provide the capacitor's initial charge D. it must match the circuit voltage and component 'C' wattage
Description : When changing out component 'B' of the circuit shown in the illustration, it is important to know that ____________. EL-0081 A. it is polarity sensitive and must be inserted as indicated on its ... provide the capacitor's initial charge D. it must match the circuit voltage and component 'C' wattage
Description : The 'reset' contacts of the master switch shown in the illustration are ______________. EL-0102 A. closed only when the master switch is 'off' B. closed only when the master switch selects a 'run' condition C. opened separately by the winch operator D. opened when line voltage drops 10%
Description : The devices labeled 'L' in the illustration are _________. EL-0003 A. load lights indicating that the generator breaker is closed and the generator is supplying power to the main bus B. ... o'clock position the lights are at their dimmest or out indicating the the generators are in phase
Description : If a circuit breaker that utilizes built-in, current limiting fuses (CLF's) cannot be closed, the problem may be traced to __________. A. a blown CLF plunger holding the trip bar in the open position B. a missing CLF C. a misaligned limiter housing assembly D. all of the above
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
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
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
Description : Protection against sustained overloads occurring in molded-case circuit breakers is provided by a/an __________. A. overvoltage release B. thermal acting trip C. thermal overload relay D. current overload relay
Description : On a vessel with turbo-electric drive, which of the following conditions would indicate that the propulsion motor had dropped out of synchronization with the propulsion generator? A. Excessive ... Tripped main motor interlocks C. Overheated crosstie busses D. Closed contact in the field circuits
Description : A circuit breaker and a fuse have a basic similarity in that they both _____________. A. can be reset to energize the circuit B. should open the circuit when overloaded C. will burn out when an over current flow develops D. all of the above
Description : An alternator is being paralleled with one on the line. At the INSTANT the circuit breaker is closed, the frequency of the incoming alternator will normally _____________. A. increase B. not change C. decrease D. be exactly 60 hertz
Description : As shown in the illustration, what is responsible for maintaining the "LV" relay energized when the master switch handle is moved away from the "off" position? EL-0102 A. "DBa" contact. B. Reset contacts. C. Upper set of "LVa" contacts. D. Lower set of "LVa" contacts.
Description : If power were lost to the winch shown in the illustration while in 'second point hoist' the winch would stop. When power is restored the winch would ______________. EL-0102 A. continue to run at ' ... switch' is returned to 'off' closing the 'reset' contacts and then moved to any 'run' position
Description : As shown in the illustration, once the "LV" relay is energized for operation, what contacts must remain closed to maintain the "LV" relay energized when the control lever is moved away from the "off" or "stop" ... . B. Reset contacts. C. Upper set of "LVa" contacts. D. Lower set of "LVa" contacts.
Description : A ground in an electrical circuit outside the engine room _____________. A. cannot be detected under normal conditions B. is of no consequence to engineering personnel C. is indicated at the branch circuit breaker panel D. is indicated by the ground detecting lamps on the main switchboard
Description : Which of the listed precautions should be taken when cleaning the internals of a motor with compressed air? A. Open the machine on both ends so as to allow the air and dust to escape. B. Be certain that the ... panel. C. Be certain that the air is clean and as dry as possible. D. All of the above.
Description : Two paralleled alternators are operating near rated load. If one trips out mechanically, which of the listed actions should be taken FIRST? A. Restart the tripped machine immediately. B. Strip the board ... circuits. C. Start the emergency generator. D. Transfer all vital loads to the emergency bus.
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 : 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
Description : An AC generator panel is fitted with both synchronizing lamps and a synchroscope. When the synchroscope pointer reaches the noon position, one synchronizing light is bright and the other is dark. This ... sequence is incorrect C. the phase sequence is correct D. the generator breaker may be closed
Description : As shown in the illustration, all 'MS' contacts are opened and closed by means of ________. EL-0073 A. operating coils B. magnets C. manual operation of the master switches D. solenoid switches
Description : Component 'C' in section 'I' shown in the illustration represent ____________. EL-0093 A. a selectable holding coil arrangement B. a 'fuse blown' indicator circuit C. 'reset' and 'trouble' lamps D. a handset with switch and voice elements
Description : When starting a DC propulsion motor the variable rheostat must FIRST be turned ____________. A. all the way to the run position then quickly back to slow B. to the slow position then gradually moved to full speed C. to the mid position D. quickly to the run position
Description : As shown in the illustration, 'B' is a ____________. EL-0058 A. single-pole, double-throw switch B. double-pole, single-throw switch C. double-pole, double-throw switch D. circuit breaker
Description : When an AC or a DC motor fails to start, the FIRST step in troubleshooting should be to check the ____________. A. motor windings for obvious opens B. motor controller leads for continuity C. fuse or circuit breaker D. motor controller leads for grounds
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
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 : In an emergency, the fastest way to interrupt power and stop the winch shown in the illustration is for the ____________. EL-0102 A. mate to open the disconnect switch at 'L1' and 'L2' B. ... watch engineer to open the winch circuit breaker D. electrician to open the test link at the controller
Description : A ground can be defined as an electrical connection between the wiring of a motor and its ____________. A. shunt field B. circuit breaker C. metal framework D. interpole
Description : The final step in testing a circuit for a ground involves the use of a megohmmeter. A grounded switch or cable will be indicated by a megohmmeter reading of ____________. A. 'zero' B. infinity C. steady in the high range D. unsteady in the low range
Description : Which of the following problems will occur if the circuit breaker of the incoming alternator is closed and it is 180° out of phase with the loaded alternator when paralleling? A. The rotor of the ... The rotor of the incoming alternator will stop. D. Both alternators will parallel 180° out of phase.
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 : 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 : A shore power circuit breaker should be closed only _____________. A. when the ship's generators have been directly paralleled to those on shore B. in a shipyard C. if a quick disconnect coupling is used D. when the ship's generators have been removed from the bus
Description : If fuse 'F-1' in the illustrated schematic diagram opens, ____________. EL-0017 A. the motor will run slowly B. 'A-1' and 'A-2' will open C. the motor will not start D. the start button will jam in the closed position
Description : When 'selector switch' 'SEL8' shown in the illustration is in the 'TEST' position, contacts '3,4' and '7,8' are respectively ____________. EL-0100 A. open; closed B. closed; open C. open; open D. closed; closed