If the illustrated motor fails to start and gives a loud hum when the start button is pushed, the problem is ________. EL-0007 A. one of the phases to the motor is not energized because of an open motor lead B. the 'Disc.sw.' is open C. power to 'L1' at the 'Disc.sw.' is not energized because of a problem with the ship's electrical distribution system D. 'OL1' is open because of 'T1' overload causing the motor to single phase

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Answer :

Answer: A

Related questions

Description : The illustrated motor fails to start and gives a loud hum when the start button is depressed, your first action should be to __________. EL-0007 A. disassemble the motor to fix the centrifical ... D. hold the 'M' contactor closed by hand while wearing electrical safety gloves to get motor started

Last Answer : Answer: B

Description : The motor starts when the start button in the illustration is pushed, but stops when the button is released the trouble is _________. EL-0007 A. the incorrect thermal overload coil B. a faulty 'M' coil C. a dirty contact on the Disc.Sw. at 'L3' D. a faulty holding relay contact

Last Answer : Answer: D

Description : If the motor fails to start and a voltmeter reading between 1 and 6, as illustrated, indicates line voltage, your next step should be to ________. EL-0007 A. replace fuse '10a' B. replace or repair contact 'Ma' C. reset and determine the cause of the overload D. check line voltage between L1 and L3

Last Answer : Answer: C

Description : If the circuit shown in the illustration were energized and operating properly, which of the devices listed would be open? EL-0007 A. The stop push-button B. The start push-button C. Contact 'Ma' D. Contact 'OL1'

Last Answer : Answer: B

Description : In the illustrated motor controller, the motor fails to start. A voltmeter reading between 1 and 6 reads line voltage, while the voltmeter reading between 2 and 6 reads 0 VAC. The problem is __________. EL- ... in the 'M' coil, 'Ma' contact/start switch or overload contacts D. fuse '10a' is blown

Last Answer : Answer: B

Description : In the illustration if the compressor fails to start but the condenser fan motor is running the problem is _______. EL-0042 A. no power between L1 and L2 B. the yellow wire is open at the freezer temperature control switch C. the overload is open D. the blue wire from the defrost heater is open

Last Answer : Answer: C

Description : In the illustration if the compressor fails to start but the condenser fan motor is running the problem is _______. EL-0043 A. no power between L1 and L2 B. the yellow wire is open at the freezer temperature control switch C. the overload is open D. the blue wire from the defrost heater is open

Last Answer : Answer: C

Description : When the motor shown in the illustration is running and the stop button is pushed, which of the following statements will hold true? EL-0010 A. Coil 'M' will now be energized. B. Coil 'CR' will now be energized. C. Contact 'M' will close as contact 'CR' opens. D. Contacts 'M' and 'CR' will open.

Last Answer : Answer: D

Description : To stop the electric motor shown in the illustration, the stop button is depressed, causing ____________. EL-0012 A. coil 'MS' to become de-energized B. contacts 'CR1' and 'MR4' to open C. contacts 'MR1', 'MR2', and 'MR3' to open D. contacts 'MS1', 'MS2', and 'MS3' to open

Last Answer : Answer: C

Description : If the three-phase motor, shown in the illustrated schematic diagram, is running in the forward direction, which of the following actions must occur before the motor will reverse rotation? EL-0011 A. Normally-closed ... 'L1' and 'L3' must be interchanged via the 'R' contacts. D. All of the above.

Last Answer : Answer: C

Description : The circuit illustrated represents a 2 wire DC ground detecting system. If the positive bus is grounded and the test button is pushed, which of the lamps will be brightest? EL-0008 A. X B. Y C. both will be equal brightness. D. both will go out.

Last Answer : Answer: C

Description : In the illustrated schematic diagram, which of the listed devices prevents the forward and reversing coils from being energized simultaneously? EL-0011 A. An 'either-or' interlock B. A mechanical interlock C. Blowout coils D. A stop button

Last Answer : Answer: A

Description : When an operating motor is connected to the controller shown in the illustration, the a path of current flow through the circuit is ____________. EL-0010 A. 'L1', stop button, start button, coil 'CR', 'L2' B. 'L1' ... L2' D. 'L1', stop button, start button, 'CR' contact, 'M' contact, 'CR' coil, 'L2'

Last Answer : Answer: B

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

Last Answer : Answer: C

Description : A short circuit in the armature of a DC motor will cause the motor to _____________. A. run fast B. hum when energized C. spark at the brushes D. fail to start

Last Answer : Answer: C

Description : Which of the following statements is true regarding the illustrated circuit? El-0069 A. This full wave bridge should never be used aboard ship because the ground on lead 'A' will show on ... be direct current suitable for electronic circuits requiring voltage regulation. D. All the above are true.

Last Answer : Answer: B

Description : If a single-phase induction motor fails to start, the problem may be _____________. A. an open in the main winding B. a shorted shunt field C. a closed centrifugal switch D. low circuit frequency

Last Answer : Answer: A

Description : If a single-phase induction motor fails to start, the problem may be _____________. A. an open in the run winding B. a shorted shunt field C. a closed centrifugal switch D. low circuit frequency

Last Answer : Answer: A

Description : Refering to the illustrated schematic diagram, which of the following statements is true when the motor is running in the forward direction? EL-0011 A. Normally-open contacts '4-5' are closed. B. Current ... switch. C. Normally-closed contacts 'R' are open. D. The blowout coils must be closed.

Last Answer : Answer: B

Description : In the illustrated device, the part labeled '1A' _________. EL-0001 A. are start and run windings for a single phase shaded pole induction motor B. is the stator for a polyphase induction ... armature for a squirrel cage rotor motor D. are direct current shunt field windings for a universal motor

Last Answer : Answer: B

Description : In a three-phase electrical system, three ground detecting lamps are provided. One lamp goes dark and the others increase in brightness. When the test button is pushed, all lamps have equal illumination. You ... C. there are grounds on the lines with the bright lamps D. this is a normal condition

Last Answer : Answer: A

Description : The correct term for the illustrated circuit is a ________. EL-0063 A. single phase half wave high power rectifier B. three phase half wave rectifier C. three phase full wave rectifier D. a single phase full wave rectifier

Last Answer : Answer: C

Description : As shown in the illustration, which of the operations listed will happen when the 'jog button' is pushed? EL-0010 A. Coil 'CR' closes the normally open 'CR' contacts. B. Coil 'M' opens contact 'M'. C. Coil 'M' closes contact 'M'. D. Contact 'M' remains open despite the jog button being pushed.

Last Answer : Answer: C

Description : The main difference between a motor control circuit containing low voltage protection and low voltage release is that the latter contains _____________. A. a magnetic operating coil B. normally open line contacts C. thermal-overload protection D. a momentary-contact start button

Last Answer : Answer: D

Description : In the illustrated test, if the lamp fails to light on any of the three windings then _________. EL-0027 A. all three windings are grounded and the motor should be sent out for repair B. ... the motor controller and the controller should be checked D. the test should be redone at a higher voltage

Last Answer : Answer: C

Description : A single-phase induction motor fails to start. The rotor is spun rapidly with the line switch closed. Having started by this method it is noted that the motor fluctuates between a very slow ... lies in the ______ A. starting winding B. centrifugal mechanism C. centrifugal switch D. running winding

Last Answer : Answer: D

Description : As shown in the illustration, 'S' is the __________. EL-0017 A. safety switch B. overload trip C. start button D. stop button

Last Answer : Answer: D

Description : In the illustrated ground detection system with a ground on phase A, if the switch is opened __________. EL-0009 A. lamp A will dim or go out depending on the severity of the ground B. all three ... lamp A will be brighter D. lamp A will start flickering if the ground is in an AC induction motor

Last Answer : Answer: B

Description : A motor controller contains three selector push buttons labeled 'start', 'jog', and 'stop'. When the 'jog' button is pushed, the motor _____________. A. will run continuously after the 'jog' button is ... 'jog' and 'start' buttons are pushed D. will not stop unless the 'stop' button is pushed

Last Answer : Answer: B

Description : If the total source voltage of the three-wire distribution system shown in the illustration is 240 volts, what is the voltage across load L1? [NOTE: Kirchhoff's voltage and current laws apply.] EL-0075 A. 110.4 volts B. 112.2 volts C. 113.3 volts D. 114.8 volts

Last Answer : Answer: D

Description : The wiring diagram for the motor starting circuit shown in the illustration indicates ______________. EL-0007 A. resistance starting B. reduced voltage starting C. low voltage protection D. low voltage release

Last Answer : Answer: C

Description : Which of the illustrations listed below is representative of a motor controller's 'schematic' or 'elementary' diagram? A. EL-0023 B. EL-0007 C. EL-0037 D. EL-0058

Last Answer : Answer: B

Description : In which section of the 24 VDC power supply circuit illustrated, does the greatest change in voltage level take place when fed from ships power. EL-0085 A. I B. II C. III D. IV

Last Answer : Answer: A

Description : Which of the following statements is true concerning the motor controller diagram shown in the illustration? EL-0023 A. Terminal 'T2' is hot only on high speed. B. Both indicating lights will be lit on ... high speed operation only. D. 'L2' is always connected to 'T2' whenever the motor is running.

Last Answer : Answer: D

Description : Component F in the illustrated device is for _________. EL-0033 A. short circut protection B. latching the trip unit closed after resetting the breaker C. overload protection D. providing a flexible connection between the input terminal G and the tripping unit E

Last Answer : Answer: C

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

Last Answer : Answer: B

Description : A single-phase induction motor will only start if you spin the rotor rapidly with the line switch closed. After starting, its speed fluctuates between very slow and half-speed. The problem ... in the ________. A. starting winding B. centrifugal mechanism C. centrifugal switch D. running winding

Last Answer : Answer: D

Description : Regarding the illustrated electrical schematic, 'S1-P', 'S1-Q', and 'S1-R' represent ____________. EL-0016 A. capacitors B. normally-closed contacts C. normally-open contacts D. normally-closed pushbutton switches

Last Answer : Answer: C

Description : The circuit illustrated represents a single phase AC ground detecting system. If a ground occurs on line 'B', which of the lamps will burn the brightest? EL-0008 A. X B. Y C. Both will be equal brightness. D. both will go out.

Last Answer : Answer: A

Description : 'A-1', as shown in the illustration, is/are ____________. EL-0017 A. normally-closed overload relay contacts B. a double pole knife switch C. normally-open overload relay contacts D. a single pole knife switch

Last Answer : Answer: A

Description : In the illustration, the assembly labeled 2 is a ________. EL-0001 A. wound rotor and shaft for a single phase induction motor B. conduction rotor and shaft for a polyphase induction motor C. ... cage rotor and shaft for a polyphase motor D. squirrel cage rotor for a single phase induction motor

Last Answer : Answer: C

Description : If a magnetic controller contactor fails to pick up when the coil voltage is applied to the contactor coil, the cause may be _____________. A. overload B. misalignment of the affected contactor contacts C. low spring pressure D. an open contactor coil

Last Answer : Answer: D

Description : As shown in the illustration, the symbol is used in electrical drawings to designate a ____________. EL-0026 A. limit switch with one set of normally open contacts B. maintaining type ... type push button with a mechanical interlock D. normally closed contact held open mechanically by an interlock

Last Answer : Answer: C