U.S.C.G. Merchant Marine Exam Third Assistant Engineer

National Maritime Center Serving Our Nation’s Mariners

U.S.C.G. Merchant Marine Exam

Third Assistant Engineer

Q536 Electrical – Electronic – Control Engineering

(Sample Examination)

Page 1 of 45 Q536 Electrical – Electronic – Control Engineering

8/18/2021

Q536 Electrical-Electronic-Control Engineering U.S.C.G. Merchant Marine Exam Third Assistant Engineer Illustrations: 27 Choose the best answer to the following Multiple Choice Questions:

1. In figure "4" of the diagram in the illustration, the three-phase step-down power transformer has a turns ratio of five to one. If a three-phase 4160 volt supply is connected to terminals "A1-B1-C1", what voltage should develop across terminals "A2-B2-C2"? Illustration EL-0084

o (A) 240 volts o (B) 415 volts • (C) 480 volts o (D) 832 volts

If choice C is selected set score to 1.

2. If a digital multimeter is set up as shown in figures "A" and "B" of the illustration, what is the status of the silicon diode if the display reads 5 megohms when configured as in figure "A" and the display reads infinite (OL) megohms when configured as in figure "B"? Illustration EL-0211

o (A) the diode is shorted o (B) the diode is open • (C) the diode is functioning properly o (D) the diode is intermittently open


3. A 480/120 VAC step-down control transformer is configured as shown in figure "E" of the illustration. When 480 VAC is applied to the primary winding (across H1 and H2), an output of 141 VAC is produced across the secondary winding (across X1 and X2). Although the fault may ultimately result in a catastrophic failure, what hypothetical fault condition is indicated that would account for these voltages? Illustration EL-0123

o (A) An open primary winding (across H1 and H2) o (B) An open secondary winding (across X1 and X2) • (C) A few shorted turns in the primary winding o (D) A few shorted turns in the secondary winding


4. To keep emergency lead-acid batteries in a full state of charge for emergency use, what is normally done?

o (A) Batteries are kept charged by cycling through discharge and charge cycles daily. o (B) Batteries are kept charged by maintaining the maximum charging rate. • (C) Batteries are kept charged by maintaining a continuous trickle charge. o (D) Batteries are kept charged by performing an equalizing charge daily.



8/18/2021

Q536 Electrical-Electronic-Control Engineering U.S.C.G. Merchant Marine Exam Third Assistant Engineer Illustrations: 27 5. As shown in figure "A" of the illustrated motor nameplate, how much current could the motor safely

draw on a continuous basis at sea level without overheating? Illustration EL-0171

o (A) 142 amps o (B) 156 amps o (C) 163 amps • (D) 187 amps

If choice D is selected set score to 1.

6. Occasionally a synchronous motor is configured without an external shaft to drive a load. In this case, the sole purpose of the synchronous motor is improving overall power factor of an electrical distribution system. What is the name of the synchronous motor so constructed?

o (A) Synchronous converter o (B) Synchronous compensator o (C) Motor-generator • (D) Synchronous condenser


7. From the information given in the illustration, which of the following statements is correct? Illustration EL-0106

o (A) The emergency generator is capable of being connected directly to the main 480 VAC bus. o (B) It is possible for the main-emergency bus-tie circuit breaker and the emergency generator

circuit breaker to be simultaneously closed. • (C) During normal operation, the main-emergency bus-tie circuit breaker and any on-line ship's

service generator circuit breakers are simultaneously closed. o (D) Shore power, in port, is only capable of feeding emergency loads.


8. Regulations require that shipboard cabling use stranded copper conductors. Why is copper a superior conductor compared to aluminum?

o (A) Even though copper has more resistance than aluminum, copper is lighter in weight than aluminum.

o (B) Even though copper is lower in conductivity than aluminum, copper has more resistance than aluminum.

o (C) Even though copper is more corrosive than aluminum, copper is lighter in weight than aluminum.

• (D) Even though copper is heavier in weight than aluminum, copper has less resistance than aluminum.



8/18/2021

Q536 Electrical-Electronic-Control Engineering U.S.C.G. Merchant Marine Exam Third Assistant Engineer Illustrations: 27 9. As shown in figure "A" of the illustration, with the switch closed what statement is true if "R1" and "R2"

have unequal resistance values? Illustration EL-0019

o (A) The voltage drop across "R1" will not be equal to the voltage drop across "R2". • (B) The current flow through "R1" will differ from the current flow through "R2". o (C) The current flow through "R1" will equal the current flow through "R2". o (D) The energy dissipated in "R1" will be the same as the energy dissipated in "R2".

If choice B is selected set score to 1.

10. What is the shape of the schematic symbol for an operational amplifier used in an analog circuit?

o (A) trapezoid o (B) square • (C) triangle o (D) circle


11. What would be the total current draw of the circuit as shown in figure "A" of the illustration if the source voltage is 24 volts, the resistance for R1 is 12 ohms, the resistance for R2 is 24 ohms, and the resistance for R3 is 36 ohms? Illustration EL-0032

o (A) 0.33 amperes o (B) 0.75 amperes o (C) 1.25 amperes • (D) 1.33 amperes


12. What type of electrical diagram for the electrical distribution system is shown in the illustration? Illustration EL-0014

o (A) The diagram is a wiring diagram. • (B) The diagram is a one-line diagram. o (C) The diagram is an isometric diagram. o (D) The diagram is a ladder or line diagram (schematic).


13. Periodic testing using a special sensing device may be performed to detect potentially dangerous loose or corroded bus bar and controller connections. What is the name of this testing technology?

o (A) electric vibro-analysis o (B) corrosion electrolysis • (C) infra-red thermography o (D) visual pyrotronics



8/18/2021

Q536 Electrical-Electronic-Control Engineering U.S.C.G. Merchant Marine Exam Third Assistant Engineer Illustrations: 27 14. To properly use a clamp-on-type ammeter for measuring current accurately, what must be done?

o (A) Enclose one conductor within the jaws AND make sure the jaws are open. • (B) Enclose one conductor within the jaws AND make sure the jaws are closed. o (C) Enclose multiple conductors within the jaws AND make sure the jaws are closed. o (D) Enclose multiple conductors within the jaws AND make sure the jaws are open.


15. As shown in figure "D" of the digital power meter shown in the illustration, what type of single phase load is under test for power measurement? Illustration EL-0256

• (A) an inductive-resistive load o (B) a purely inductive load o (C) a purely resistive load o (D) a resistive-capacitive load

If choice A is selected set score to 1.

16. When a battery-operated megohmmeter (insulation tester) is used to perform a dielectric absorption test, the resistance is measured and recorded from each conductor to ground each minute for 10 consecutive minutes. What condition accounts for a gradual rise in resistance each successive minute?

o (A) The insulation is contaminated with moisture. o (B) The insulation has direct continuity with ground. o (C) The insulation is cracked and otherwise deteriorated. • (D) The insulation is in good condition.


17. As the electrolyte level in the cells of a lead-acid battery evaporates over time, what will tend to happen to the specific gravity of the electrolyte in the cells as the level drops due to evaporation?

o (A) Although the specific gravity will change due to evaporation, there is no predictable tendency either way.

o (B) The specific gravity of the electrolyte will decrease as only the sulfuric acid will evaporate from the electrolyte solution.

• (C) The specific gravity of the electrolyte will increase as only the water will evaporate from the electrolyte solution.

o (D) The specific gravity of the electrolyte will remain unchanged as both the water and sulfuric acid will evaporate from the electrolyte solution.



8/18/2021

Q536 Electrical-Electronic-Control Engineering U.S.C.G. Merchant Marine Exam Third Assistant Engineer Illustrations: 27 18. As shown in the illustrated diagnostic setup for locating a shorted field coil of a ten-pole synchronous

motor, if 240 VAC/60 Hz is applied across the brushes, what would be the individual voltage drops measured across each field coil assuming that none of the field coils are shorted? Illustration EL-0202

o (A) 6 VAC o (B) 12 VAC • (C) 24 VAC o (D) 48 VAC


19. If the motor shown in the illustration will not start when the "off-run" switch is placed in the run position, which of the listed components should be checked FIRST? Illustration EL-0017

o (A) check the disconnect switch open, open as necessary o (B) check the overload relay (OL) heaters for continuity, replace as necessary o (C) check the main contactor coil for continuity, replace as necessary • (D) check the overload relay for tripped condition, reset as necessary


20. From the information given in the illustration, what would be the ampere capacity at full load of each of the main ship service diesel-generators if operating at the rated power factor of 0.8? Illustration EL-0106

o (A) 2500 amps • (B) 3011 amps o (C) 4325 amps o (D) 5208 amps


21. No.1 SSDG was operating in parallel with No.2 SSDG in supplying the 480 VAC main bus while sharing the electrical load evenly. As a result of a problem, if No.1 SSDG begins to motorize, but the generator has not yet tripped out by the action of the reverse power relay, what would be the indication of this?

o (A) The power factor meter of No.1 SSDG would indicate unity (1.0). o (B) The kilowatt meter of No.1 SSDG would indicate a higher wattage compared to when the load

was equally shared. o (C) The ammeter of No.1 SSDG would indicate a higher amperage compared to when the load

was equally shared. • (D) The kilowatt meter of No.1 SSDG would drop below 0 kW.



8/18/2021

Q536 Electrical-Electronic-Control Engineering U.S.C.G. Merchant Marine Exam Third Assistant Engineer Illustrations: 27 22. What is the most reliable and preferred method for determining the state of charge of a wet cell

NiCad battery while it is being charged?

• (A) Measuring the battery voltage with a digital voltmeter. o (B) Measuring the battery voltage with a solenoid type voltage tester. o (C) Measuring the temperature corrected specific gravity of each cell with a hydrometer and

thermometer. o (D) Measuring the specific gravity of each cell with a hydrometer.


23. The torque-speed and current-speed curves for a three-phase induction motor with a squirrel-cage rotor are shown in figures "A" and "B" of the illustration. Which of the following statements is true concerning the depicted curves? Illustration EL-0056

• (A) Starting current is approximately 4.75 times the normal full load current value. o (B) The pull-up point on the torque curve is about 20% of the normal full load torque value. o (C) The starting current is nearly 1.5 times the normal full load current value. o (D) Rated torque and rated current occur at approximately 20% slip.


24. A degree of control over the speed of a slip ring induction motor can be obtained by what means?

• (A) inserting resistance into the rotor circuit o (B) changing the number of phases to the motor o (C) inserting resistance into the stator circuit o (D) adjusting governor linkage


25. What is the function of the movable cams in a master-switch winch motor drum controller?

o (A) insulate the operating handle • (B) regulate the speed of the motor o (C) maintain resistance contacts in clean condition o (D) limit the amount of load put on the motor


26. Concerning the illustrated motor controller circuit, where is the location of the motor "run" indicator light? Illustration EL-0004

o (A) There is no motor "run" light. It is, instead, a motor "stopped" light. • (B) At the remote operating station. o (C) At the motor. o (D) At the local control station.



8/18/2021

Q536 Electrical-Electronic-Control Engineering U.S.C.G. Merchant Marine Exam Third Assistant Engineer Illustrations: 27 27. As shown in the illustration of an electrically operated watertight door controller, how is the motor

stopped automatically when the door is wedged closed? Illustration EL-0115

o (A) Momentarily depressing open push button switch. • (B) Action of door closed limit switch (LSC). o (C) Action of motor overload (OL). o (D) Action of door open limit switch (LSO).


28. Upon failure of the normal power supply, by what means is the emergency generator placed on the line and connected to the emergency bus?

o (A) line connection feeder • (B) automatic bus transfer device o (C) power failure alarm bus o (D) bus tie feeder


29. Which of the following statements about a three-phase wye connected alternator is correct?

o (A) The line current is 1.73 times the phase current. • (B) The line voltage is 1.73 times the phase voltage. o (C) The phase voltage is 1.73 times the line voltage. o (D) The phase current is 1.73 times the line current.


30. The arc resulting from the tripping of a circuit breaker is prevented from damaging the contacts. How is this done?

o (A) an inverse timed thermal trip for short circuit currents o (B) designing the contacts to open slowly • (C) extinguishing the arc by means of an arc chute o (D) instantaneous magnetic trip for overload currents


31. Incandescent lamps are classified according to the shape of the bulb and the type of service, as well as the size and style of the base. How are incandescent lamps rated?

o (A) operating resistance o (B) operating reactance • (C) operating voltage and wattage o (D) operating frequency and impedance



8/18/2021

Q536 Electrical-Electronic-Control Engineering U.S.C.G. Merchant Marine Exam Third Assistant Engineer Illustrations: 27 32. Referring to the containership one-line distribution diagram shown in the illustration, what is the

purpose of the feedback circuit breaker as used to bypass the automatic bus transfer device? Illustration EL-0014

o (A) Since it is normally closed, it is the means by which the emergency generator control circuit senses the voltage at the emergency bus.

o (B) It allows the emergency generator to be paralleled with the ship's service generators when additional power is needed.

• (C) It allows the emergency generator to feed the main bus during dead ship start-up; otherwise it is generally open and not used.

o (D) Since it is normally closed, it is the means by which the emergency generator control circuit senses the voltage at the main bus.


33. When placed in a magnetic field, which of the materials listed has the highest permeability?

o (A) Aluminum • (B) Iron o (C) Glass o (D) Bakelite


34. Which of the following statements correctly applies to bipolar junction transistors?

o (A) LED and LCD are the two basic types of transistors. • (B) The three terminals are called the emitter, base, and collector. o (C) The collector separates the emitter and base. o (D) The emitter separates the base and collector.


35. A common-emitter circuit has an input voltage of 0.1 volt, an output voltage of 2.0 volts, an input current of 0.5 milliamps, and an output current of 10 milliamps. What is the power gain?

o (A) 20 o (B) 40 • (C) 400 o (D) 4000



8/18/2021

Q536 Electrical-Electronic-Control Engineering U.S.C.G. Merchant Marine Exam Third Assistant Engineer Illustrations: 27 36. In referring to figure "A" of the illustration, what type of active filter circuit is shown? Illustration EL-

0077

• (A) Low-pass filter circuit o (B) High-pass filter circuit o (C) Bandpass filter circuit o (D) Notch filter circuit


37. Referring to figure "3" of the illustration, what type of logic gate is symbolized? Illustration EL-0035

o (A) OR gate o (B) XOR gate • (C) AND gate o (D) NOR gate


38. Of the following, what shipboard system is MOST likely to use the synchronous transmission system featuring a transmitter and receiver?

o (A) Centrifuge RPM indicator system o (B) Turbocharger RPM indicator system • (C) Rudder angle indicator system o (D) Shaft revolution indicator system


39. As shown in the illustrated block diagram for a distributed automation system, what statement is true concerning the units labeled "ROS" which are remote operating system workstations? Illustration EL-0096

o (A) The ROS located in the ship's office is designated as the master ROS. o (B) The ROS located in the wheelhouse is designated as the master ROS. o (C) Operator access to control functions among the various ROS locations are all identical. • (D) Operator access to control functions among the various ROS locations differ depending

system configuration and need.



8/18/2021

Q536 Electrical-Electronic-Control Engineering U.S.C.G. Merchant Marine Exam Third Assistant Engineer Illustrations: 27 40. As shown in the illustration, what statement is true concerning each of the system gateways?

Illustration EL-0098

o (A) Each connects one of two redundant automation area networks with both redundant engine control process area networks.

o (B) Each connects one of two redundant automation area networks with both redundant cargo process area networks.

• (C) Each connects one of two redundant automation area networks with one of two redundant engine control process area networks and one of two redundant cargo process area networks.

o (D) Each connects one of two redundant automation area networks with the other automation area network.


41. Referring to the impressed current cathodic hull protection system shown in the illustration, if required to control the impressed current to the anodes manually by using the hand adjustment potentiometer, what parameter should be maintained at a constant value? Illustration EL-0090

o (A) Total anode current • (B) Reference electrode voltage o (C) Control amplifier output voltage o (D) Individual anode currents


42. Referring to the illustration of a steering gear hydraulic power unit motor controller, if the motor is drawing current no greater than full load current, what will the status of the overload relay contacts and the control relay contacts be? Illustration EL-0119

o (A) The overload relay contacts will be OPEN The control relay contacts will be CLOSED

o (B) The overload relay contacts will be OPEN The control relay contacts will be OPEN

• (C) The overload relay contacts will be CLOSED The control relay contacts will be OPEN

o (D) The overload relay contacts will be CLOSED The control relay contacts will be CLOSED


43. The current at which a magnetic-type overload relay tends to trip may be decreased by raising the plunger further into the magnetic circuit of the relay. What effect does this action have?

o (A) increases magnetic pull on the plunger and requires more current to trip the relay • (B) increases magnetic pull on the plunger and requires less current to trip the relay o (C) reduces magnetic pull on the plunger and requires more current to trip the relay o (D) reduces magnetic pull on the plunger and requires less current to trip the relay



8/18/2021

Q536 Electrical-Electronic-Control Engineering U.S.C.G. Merchant Marine Exam Third Assistant Engineer Illustrations: 27 44. Large machines undergoing a resistance insulation testing using a megohmmeter should be

discharged to remove any accumulated electrostatic/capacitive/dielectric-absorption charge stored. When should this discharge be performed?

o (A) prior to conducting the insulation resistance check only o (B) while performing the insulation resistance check only o (C) after conducting the insulation resistance check only • (D) prior to and after conducting the insulation resistance check


45. Why must caution be exercised during the charging of flooded lead-acid storage batteries?

• (A) hydrogen gas can be liberated during charging o (B) both plates are changing chemically to lead sulfate o (C) the acid will become weaker o (D) lead peroxide in the negative plate is poisonous


46. When a self-excited alternator's field has lost its residual magnetism due to a prolonged idle period, it will fail to produce a voltage. Flashing the field is the procedure used to restore the residual magnetism. Using a 12 volt storage battery, how is this performed?

• (A) The F+ and F- leads are disconnected from the alternator field. The F+ lead is connected to the positive terminal of the battery, and the F- lead is connected to the negative terminal.

o (B) The F+ and F- leads are disconnected from the alternator field. The F+ lead is connected to the negative terminal of the battery, and the F- lead is connected to the positive terminal.

o (C) The S+ and S- leads are disconnected from the alternator stator. The S+ lead is connected to the negative terminal of the battery, and the S- lead is connected to the positive terminal.

o (D) The S+ and S- leads are disconnected from the alternator stator. The S+ lead is connected to the positive terminal of the battery, and the S- lead is connected to the negative terminal.


47. Before electrical work can be safely undertaken, the equipment must be de-energized, locked and tagged out, and verification must be made that the circuit is actually dead. What testing device is most certain to reliably verify that a circuit is actually dead?

o (A) a solenoid type voltage tester • (B) an autoranging digital multimeter o (C) a non-contact voltage tester o (D) a non-autoranging digital multimeter



8/18/2021

Q536 Electrical-Electronic-Control Engineering U.S.C.G. Merchant Marine Exam Third Assistant Engineer Illustrations: 27 48. In accordance with 46 CFR Subchapter J (Electrical Engineering), which of the following starting

aids is the ONLY method allowed to ease the starting of emergency diesel-generator engines?

o (A) Electric, steam, or hot water heated lube oil heaters o (B) Ether injection systems o (C) Electric air intake heaters • (D) Thermostatically controlled electric jacket water heaters


49. Which of the listed temperature measuring devices installed on a large turbo-electric alternating current propulsion generator would be the most reliable for monitoring generator temperatures to avoid premature winding insulation failure?

o (A) Current transformers are the most reliable means of monitoring generator temperatures. • (B) Temperature sensors inserted in the stator slots for measuring stator winding temperature. o (C) Temperature sensors measuring the temperature of the cooling air associated with the

generator air cooler. o (D) Temperature sensors measuring the temperature of the cooling water associated with the

generator air cooler.


50. By what common means is the speed of an AC propulsion motor on a diesel-electric propulsion ship controlled?

o (A) by varying the input frequency to the motor, but not the voltage • (B) by varying both the input frequency and voltage to the motor o (C) by varying either the input voltage or frequency to the motor, but not both o (D) by varying the input voltage to the motor, but not the frequency


51. Before work may safely commence on a high voltage system, what must first be done after disconnection and isolation?

o (A) The circuit must be grounded first, then tested and proved dead with an off-line tester. o (B) The circuit must be grounded first, then tested and proved dead with a live-line tester. • (C) The circuit must be tested and proved dead first with a live-line tester, then grounded. o (D) The circuit must be tested and proved dead first with an off-line tester, then grounded.



8/18/2021

Q536 Electrical-Electronic-Control Engineering U.S.C.G. Merchant Marine Exam Third Assistant Engineer Illustrations: 27 52. In order for a live-line tester to be used to test and prove dead a high voltage circuit, what must be

done to verify the ability of the tester to detect a voltage?

o (A) The live-line tester should be checked by connecting to a known high voltage source only before testing the circuit to be worked upon.

o (B) The live-line tester should be checked by connecting to a known high voltage source only after testing the circuit to be worked upon.

• (C) The live-line tester should be checked by connecting to a known high voltage source before and after the circuit to be worked upon is tested.

o (D) The live-line tester need not be checked prior to testing the circuit to be worked upon as long as it has not been declared inoperative.


53. In a podded azimuthing propulsion system, how is three-phase, frequency and voltage controlled power delivered to the synchronous propulsion motor stator windings?

o (A) By the use of commutator bars and brushes. • (B) By the use of slip rings and brushes. o (C) By direct connection to the stator windings. o (D) By rotary transformer action.


54. Referring to the sound-powered telephone circuit shown in illustration, what statement is true concerning the button on the handset as represented by the component labeled "A"? Illustration EL-0093

o (A) The push button is depressed only for the purposes of listening, and it should be released for talking.

o (B) The push button is depressed only for the purposes of conversing with multiple stations. For a conversation between two stations, it is not needed.

• (C) The push button is depressed for the purposes of listening and talking. o (D) The push button is depressed only for the purposes of talking, and it should be released for

listening.


55. Before any work on electrical or electronic equipment is performed, which of the following precautions should be carried out?

o (A) De-energize the applicable switchboard bus. • (B) Secure and tag the supply circuit breaker in the open position. o (C) Bypass the interlocks. o (D) Station a man at the circuit supply switch.



8/18/2021

Q536 Electrical-Electronic-Control Engineering U.S.C.G. Merchant Marine Exam Third Assistant Engineer Illustrations: 27 56. When a fluorescent lamp has reached the end of its useful life, it should be replaced immediately. If

not, what condition could the resultant flashing cause?

o (A) tripping of the lamp's circuit breaker o (B) short circuiting of adjacent lighting circuits o (C) exploding of the lamp, causing glass to fly in all directions • (D) damaging the lamp's ballast circuit


57. How may the unit "hertz" be best described?

• (A) cycles per second o (B) revolutions per second o (C) coulombs per second o (D) revolutions per minute


58. An AC generator produces 60 Hz at 1800 RPM. If the generator speed is increased to 1830 RPM, what will happen to the frequency in Hz?

o (A) decrease to 59 Hz o (B) remain at 60 Hz • (C) increase to 61 Hz o (D) increase to 63 Hz


59. As shown in figure "A" of the illustration, what would be the circuit impedance if the capacitive reactance is 10 ohms and the resistance is 10 ohms? Illustration EL-0109

o (A) 4.47 ohms capacitive o (B) 6.32 ohms capacitive • (C) 14.14 ohms capacitive o (D) 20 ohms capacitive


60. What would be the actual rotor speed for a 4-pole three-phase squirrel-cage induction motor operating at 60 Hz if the rotor slip is 3%?

• (A) 1746 RPM o (B) 1793 RPM o (C) 1800 RPM o (D) 1854 RPM



8/18/2021

Q536 Electrical-Electronic-Control Engineering U.S.C.G. Merchant Marine Exam Third Assistant Engineer Illustrations: 27 61. Refer to the simplified diagram of the AC synchronous electric motor drive system as shown in the

illustration. The propulsion motor operates from maneuvering speed to full ahead speed in the ahead direction. The propulsion motor will not operate at any speed in the astern direction. What is most likely the problem? Illustration EL-0155

o (A) The AC propulsion motor has an open astern winding. o (B) Due to a controller fault, the power supply to the controlled rectifier fails to achieve a phase

sequence reversal. • (C) Due to a controller fault, the output of the controlled inverter fails to achieve a reversal in

phase sequence. o (D) The AC propulsion motor field winding fails to reverse in polarity.


62. The winch shown in the illustration operates in any of the positions with the master switch in the 'lower' direction, but will not 'hoist' in any of the master switch hoist speed positions. Which of the listed faults would MOST likely be the cause? Illustration EL-0102

o (A) The undervoltage relay contacts between terminals 1 and 2 have failed open. o (B) The AC hoist motor has tripped out on overload, permitting only lowering. • (C) The hoist limit switch (LSH) contacts across terminals 9 and 10 have failed open. o (D) The lower limit switch (LSL) contacts across terminals 5 and 6 have failed open.


63. Within the split-phase family of single phase motors, what are the operational characteristics of the motor shown in figure "A" of the illustration? Illustration EL-0207

o (A) Relatively low starting torque with power factor correction o (B) Relatively high starting torque with no power factor correction o (C) Relatively high starting torque with power factor correction • (D) Relatively low starting torque with no power factor correction


64. A common type of molded case circuit breaker has both thermal and magnetic trip elements. If a branch circuit breaker has only thermal or magnetic trip elements (but not both), it is common to use multiple series-connected protective devices to provide both short-circuit and overload protection. If a motor branch circuit is protected with both a thermal trip-type circuit breaker and fuses, what is the protective purpose of the fuses used in this arrangement?

o (A) time-delay protection o (B) short duration surge protection o (C) sustained overload protection • (D) short-circuit protection



8/18/2021

Q536 Electrical-Electronic-Control Engineering U.S.C.G. Merchant Marine Exam Third Assistant Engineer Illustrations: 27 65. When a transformer is used to step down voltage, what statement is true?

o (A) The low voltage winding is part of the core. o (B) The low voltage winding is the primary coil. • (C) The low voltage winding is the secondary coil. o (D) The low voltage winding is not insulated.


66. In the diagram of the switchboard shown in the illustration, what is the function of the device labeled "Gen. Bkr. Sw."? Illustration EL-0003

o (A) it allows the alternator circuit breaker short circuit trip rating to be remotely adjusted at the synchronizing panel

• (B) it allows the alternator circuit breaker to be opened or closed remotely at the synchronizing panel

o (C) it allows the alternator circuit breaker trip function to be over-ridden o (D) it allows the alternator circuit breaker overload inverse time trip rating to be remotely adjusted

at the synchronizing panel


67. How is the main propeller shaft rotation of a rectified DC diesel-electric drive normally reversed?

• (A) reversing the field or armature polarity of the DC motor o (B) reversing the field polarity in the AC generator o (C) reversing the polarity of the interpoles o (D) reversing the diesel engine rotation


68. Referring to the illustration pertaining to a steering system hydraulic power unit motor controller, what statement is true concerning a response to a motor overload condition as visualized by the indicator lamps? Illustration EL-0119

o (A) Run indicator lamp is OFF Overload indicator lamp is OFF

o (B) Run indicator lamp is OFF Overload indicator lamp is ON

• (C) Run indicator lamp is ON Overload indicator lamp is ON

o (D) Run indicator lamp is ON Overload indicator lamp is OFF



8/18/2021

Q536 Electrical-Electronic-Control Engineering U.S.C.G. Merchant Marine Exam Third Assistant Engineer Illustrations: 27 69. In actual applications, electrical connections associated with "R1, R2 and R3" of the transmitter to

"R1, R2, and R3" of the indicators shown in figure "C" of the illustration are made by what means? Illustration EL-0092

o (A) spliced and taped connections o (B) solderless crimp-on connectors • (C) slip rings and brushes o (D) soldered contacts


70. Which of the following statements, concerning the cleaning maintenance of a brushless generator, is correct?

o (A) High-pressure air should be used to blow out dust and grime from the windings. o (B) Hot soapy water should be used to remove dust and grime from windings. o (C) Cleaning of windings should be performed on a periodic basis regardless of the state of

cleanliness. • (D) Cleaning of windings should be performed on a conditional basis using a vacuum or using a

clean, dry, lint-free rag.



8/18/2021

National Maritime Center

Serving Our Nation’s Mariners

10/5/2018

EL-0003

Adapted for testing purposes only from HUBERT, Operating, Testing and Preventive

Maintenance of Electrical Power Apparatus.

Copyright © 2003 Pearson Education

Further reproduction prohibited without permission Page 19 of 45 Q536 Electrical – Electronic – Control Engineering



10/5/2018

EL-0004

Adapted for testing purposes only from HALL, Practical Marine Electrical Knowledge, 2E

Copyright © 2003 Dennis T. Hall

Further reproduction prohibited without permission Page 20 of 45




2/21/2020

EL-0014

Adapted for testing purposes only from HUNT, Modern Marine Engineer’s Manual,

Volume II, Third Edition

Copyright © 2002 by Cornell Maritime Press, Inc.





7/8/2019

EL-0017

Adapted for testing purposes only from HARRINGTON, Marine Engineering

Copyright © 1992 by the Society of Naval Architects and Marine Engineers




10/5/2018

EL-0019

Adapted for testing purposes only from GROB, Basic Electronics, Fourth Edition

Copyright © 1977 by McGraw-Hill, Inc.





10/5/2018

EL-0032

Adapted for testing purposes only from GROB, Basic Electronics, Fourth Edition

Copyright © 1977 by McGraw-Hill, Inc.





10/5/2018

EL-0035

Adapted for testing purposes only from HERMAN, Industrial Motor Control, 6th Edition

Copyright © 2010 by Delmar, Cengage Learning





10/5/2018

EL-0056


Maintenance of Electrical Power Apparatus

Copyright © 2003 Pearson Education





10/5/2018

EL-0077

Adapted for testing purposes only from KILIAN, Modern Control Technology, 3rd Edition

Copyright © 2006 by Delmar, Cengage Learning

Further reproduction prohibited without permission

Page 27 of 45




10/5/2018

EL-0084

Adapted for testing purposes only from HUBERT, Operating, Testing, and Preventive


Copyright © 2003 by Pearson Education, Inc.


Page 28 of 45




10/5/2018

EL-0090

Adapted for testing purposes only from HALL, Practical Marine Electrical Knowledge, 2nd Edition

Copyright © 2003 by Dennis T. Hall


Page 29 of 45




10/5/2018

EL-0092

Adapted for testing purposes only from SMITH, Modern Marine Electricity and Electronics



Page 30 of 45




10/5/2018

EL-0093

Adapted for testing purposes only from HOSE-McCANN, Sound Powered Telephones

Copyright © 1964 by Hose-McCann Telephone Co.


Page 31 of 45




10/9/2018

EL-0096

Adapted for testing purposes only from HUNT, Modern Marine Engineer’s Manual, Volume II, 3rd Edition



Page 32 of 45




10/9/2018

EL-0098

Adapted for testing purposes only from HUNT, Modern Marine Engineer’s Manual, Volume II, 3rd Edition






6/13/2019

EL-0102

Adapted for testing purposes only from HUBERT, Operating, Testing, and Preventive


Copyright © 2003 by Pearson Education, Inc.


Page 34 of 45




10/9/2018

EL-0106 One Line Distribution Diagram

Adapted for testing purposes only from HARRINGTON, Marine Engineering

Copyright © 1992 by The Society of Naval Architects and Marine Engineers


Page 35 of 45




10/9/2018

EL-0109

Adapted for testing purposes only


Page 36 of 45




10/9/2018

EL-0115 Watertight Door Controller







10/9/2018

EL-0119







10/9/2018

EL-0123

Adapted for testing purposes only from MILLER, Industrial Electricity and Motor Controls

Copyright © 2008 by McGraw-Hill Companies, Inc.





10/10/2018

EL-0155

Adapted for testing purposes only from HALL, Practical Marine Electrical Knowledge, 3rd Edition

Copyright © 2014 by Dennis T. Hall


Page 40 of 45




10/10/2018

EL-0171

Standard Overload Relays General Instructions for Selection of Overload Relay Heater Elements:

1. Obtain full load current and service factor from motor nameplate of from motor manufacturer. Donot estimate full-load motor current from horsepower tables.

2. Determine if 1, 2, or 3 overload relays are needed.3. Select proper heater from appropriate table according to class, size, type of enclosure and number

of overload relays being used. Full load motor currents should be within the Min.-Max. ratingsshown for the number of overload relays being used.

4. The tables apply only to standard, open type or totally enclosed fan-cooled, continuous dutymotors (with a service factor of 1.15 and rated for 40 degrees C rise) in applications where motorand starter are located in the same ambient temperature. For applications of other motors with aservice factor of 1, 50-55 degrees C rise, totally enclosed non-ventilated, explosion proof, or forinstallations where ambient temperatures of motor and starter are different, refer to Chart “A” forselection of overload heater units.

Chart A: Variations by Operating Conditions Motor continuous rating C rise

Ambient temperature same at starter and motor

Ambient temperature higher at starter than at motor

Ambient temperature lower at starter than at motor

1.5 service factor 40 C rise

As specified from tables One size larger than specified for each 15 C difference

One size smaller than specified for each 15 C difference

1.0 service factor 50-55 C rise

One size smaller than for 1.15 service factor as above



Table 24: NEMA Size 6 for all Standard Enclosures Three Overload Relays per Starter

Adapted for testing purposes only from MAZUR, Troubleshooting Electric Motors, 4th Edition

Copyright © 2010 by American Technical Publishers, Inc. Further reproduction prohibited without permission

Heater Cat. No

Motor Current

Min. Max.

G30T19 142 157

G30T20 158 171

G30T21 172 188

G30T22 189 207

G30T23 208 229

Heater Cat. No

Motor Current

Min. Max.

G30T24 230 252

G30T25 253 277

G30T26 278 306

G30T27 307 336

G30T28 337 368

Heater Cat. No

Motor Current

Min. Max.

G30T29 369 405

G30T30 406 459

G30T31 460 480




10/10/2018

EL-0202



Copyright © 2003 Pearson Education Further reproduction prohibited without permission Page 42 of 45




10/10/2018

EL-0207







10/10/2018

EL-0211

Adapted for testing purposes only




3/5/2019

EL-0256





Documents

U.S.C.G. Merchant Marine Exam Third Assistant Engineer