Motor name plate data includes '°°C rise'. This indicates the _____________. A. actual running temperature of the winding from no load to full load  B. permissible temperature rise of the windings above the designed ambient temperature C. maximum allowable temperature rise above normal full load operating temperature D. maximum allowable temperature rise for continuous no load service

1 Answer

Answer :

Answer: B

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Description : One item listed on the name plate of a cargo pump motor is 'degrees centigrade rise.' This number is based on _____________. A. normal temperature change from cold to hot B. an ambient temperature ... . minimum heat rise from no load to full load D. maximum degrees centigrade rise from absolute zero

Last Answer : Answer: B

Description : The rated temperature rise of an electric motor is the _____________. A. average temperature at any given latitude B. normal temperature rise above the standard ambient temperature at rated load ... D. permissible difference in the ambient temperature of the motor due to existing weather conditions

Last Answer : Answer: B

Description : Ambient temperature is the _____________. A. amount of temperature rise with no load B. amount of temperature developed by an operating motor C. temperature of the compartment where the motor is located D. normal operating temperature, less the room temperature

Last Answer : Answer: C

Description : Ambient temperature is the _____________. A. amount of temperature rise with no load B. temperature of the compartment where the motor is located C. normal operating temperature, less the room temperature D. amount of temperature developed by an operating motor

Last Answer : Answer: B

Description : An insulation resistance test is performed on a particular piece of electric equipment. In addition to the resistance reading, what information listed below should be entered in the electrical log? A. ... D. The complete nameplate data from the resistance test instrument used to obtain the reading.

Last Answer : Answer: B

Description : While starting a main propulsion synchronous motor, the ammeter pegs out at maximum and then returns to the proper value after synchronization. This indicates the _____________. A. motor has started ... field windings are grounded C. slip rings are dirty D. power transmission cables are grounded

Last Answer : Answer: A

Description : In preparing to take insulation resistance readings on a main generator, the windings should be grounded for about 15 minutes prior to the test to _____________. A. allow accurate zeroing of the meter ... the windings D. help the windings to cool to the same temperature as the ground test connection

Last Answer : Answer: C

Description : Which of the following statements is true concerning all three-phase alternators? A. Each has three separate but identical armature windings acted on by one system of rotating magnets. B. Each has one ... The three phases always provide power to the load through three sets of slip rings and brushes.

Last Answer : Answer: A

Description : When troubleshooting a magnetic controller, it is found that the contacts are welded together. The most probable cause is _____________. A. excessive operation at low load B. high ambient temperature C. low voltage on the operating coil D. high voltage on the operating coil

Last Answer : Answer: C

Description : Basically, a magnetic amplifier is a saturable reactor with the addition of _____________. A. AC to the bias winding B. variable capacitance to all windings C. eddy current protectors D. a rectifier in the load circuit

Last Answer : Answer: D

Description : An operating characteristic appearing on the name plates of shipboard AC motors is _____________. A. the type of winding B. input kilowatts C. temperature rise D. locked rotor torque

Last Answer : Answer: C

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

Last Answer : Answer: A

Description : If the centrifugal switch or relay used for cutting out the starting winding of a split-phase induction motor fails to open once the motor is in operation, the _____________. A. motor will overspeed B ... C. motor will immediately stall under load D. motor torque will be above normal at rated speed

Last Answer : Answer: B

Description : The speed of a multi-speed, squirrel-cage, induction motor operating in a fixed frequency system can be changed by _____________. A. reconnecting stator windings for different numbers of poles B. ... sequence of the applied voltage D. reconnecting the stator so that no poles have the same polarity

Last Answer : Answer: A

Description : Unless it can be shown that a 45°C ambient temperature will not be exceeded, motors within a machinery space must be designed for an ambient temperature of _____________. A. 45°C B. 50°C C. 55°C D. 60°C

Last Answer : Answer: B

Description : Which of the conditions listed will indicate the need to clean the insulation on the windings of an electric motor? A. Higher than normal operating temperature. B. Excessive vibration at normal speed. C. Sparking at the brushes. D. High megger readings.

Last Answer : Answer: A

Description : Magnetic controller contacts may become welded together during operating conditions as a result of _____________. A. high spring pressure B. high ambient temperature C. an open coil D. low voltage on operating coil

Last Answer : Answer: D

Description : Which statement is true concerning a split-phase induction motor? A. Motor rotation can be reversed without changing the windings or leads. B. Motor speed can be readily adjusted from zero to full ... proper wiring. D. Motor rotation can be reversed by reversing the leads on the starting winding.

Last Answer : Answer: D

Description : A ground is indicated by the ground-detecting system on the main electrical switchboard. The FIRST step in locating the actual ground is to _____________. A. close all circuit breakers in ... ground detection system indicates normal C. change over generators D. check each circuit with a megohmmeter

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Description : The speed of a three-phase squirrel-cage induction-type motor operating in a fixed frequency system is varied by changing the _____________. A. number of phases to the motor B. number of stator poles C. locked rotor current D. resistance of the rotor winding

Last Answer : Answer: B

Description : The main purpose of the auxiliary winding on a split-phase, single-phase motor is to _____________. A. limit the starting voltage B. increase the starting current C. start the motor D. keep the motor running in the event the main winding should fail

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Description : If a DC motor runs hot, the cause may be _____________. A. high mica condition B. low ambient temperature C. clogged ventilation ducts D. an open in the shunt field

Last Answer : Answer: C

Description : Electric strip heaters are used in motor controllers to _____________. A. prevent freezing of movable contacts B. keep the components at their design ambient temperature C. prevent condensation of moisture D. minimize resistance in internal circuits

Last Answer : Answer: C

Description : To repair a small electrical motor that has been submerged in saltwater, you should _____________. A. wash it with fresh water and apply an external source of heat B. renew the windings ... electrical parts with a carbon tetrachloride cleaning solvent and then blow dry the motor with compressed air

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Description : In a capacitor start single-phase induction motor, the capacitor is connected (A) in series with main winding. (B) in series with auxiliary winding. (C) in series with both the windings. (D) in parallel with auxiliary winding.

Last Answer : Ans: B To make single phase motor self start. We split the phases at 90 degree. Hence, motor behaves like a two phase motor.

Description : When a megohmmeter is used to test insulation, the gradual rise of the pointer reading as a result of continued cranking, is caused by _____________. A. good conductor resistance B. the ... insulation C. the inductive reactance of the windings D. the dielectric-absorption effect of the insulation

Last Answer : Answer: D

Description : Shading coils are installed on AC full-voltage starters to _____________. A. eliminate contact chatter B. dissipate opening contact arcs C. delay current build up in the holding coil D. protect the motor windings from momentary starting current overload

Last Answer : Answer: A

Description : To check the three line fuses of a three-phase system consisting of a three-phase motor, you must _____________. A. place the starter in the 'stop' position B. make sure the motor is operating at full ... leads across the 'hot' ends of the fuses D. place the leads across the bottom ends of the fuses

Last Answer : Answer: A

Description : Routine maintenance of dry-type transformers should include ____________. A. cleaning the windings, if accessible, with a vacuum cleaner or very low pressure air B. measuring and recording the winding ... . making sure that the units are close to bulkheads or corners to protect them from damage

Last Answer : Answer: A

Description : A megohmmeter is connected to each end of an individual motor winding. A low ohm reading indicates ____________. A. an open coil B. a loose coil C. good continuity D. a dirty coil

Last Answer : Answer: C

Description : The energy consumed by an AC motor, as strictly reactive power, is _____________. A. used to do mechanical work B. used to establish the magnetic field of the motor C. lost as heat generated by the windings D. lost in doing work to turn the motor itself

Last Answer : Answer: B

Description : The reactive power drawn by a motor from an AC generator is the power which is _____________. A. used to establish the magnetic field of the motor B. lost in overcoming friction in the ... by current flow through the windings D. transmitted directly through the rotor shaft to perform useful work

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Description : In a series wound motor, the current passing through the field windings is also passing through the _____________. A. armature B. shunt field C. reactance comparator D. laminations

Last Answer : Answer: A

Description : The speed of a squirrel-cage motor is usually changed by _____________. A. varying the frequency to the machine B. adding resistance in series with the stator windings C. adding resistance in parallel with the stator windings D. changing the number of connected poles in the stator

Last Answer : Answer: D

Description : In a three-phase, squirrel-cage type, induction motor the rotating magnetic field is established by the _____________. A. current induced in the rotor windings B. application of a three-phase voltage ... caused by the induced current in the squirrel-cage bars with the magnetic field of the stator

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Description : The function of amortisseur, or damper windings in a synchronous motor is to _____________. A. eliminate slippage B. provide excitation C. provide starting torque D. increase efficiency

Last Answer : Answer: C

Description : The function of damper windings in a synchronous motor is to _____________. A. eliminate slippage B. provide excitation C. provide starting torque D. increase efficiency

Last Answer : Answer: C

Description : Amortisseur windings are installed in a synchronous motor to _____________. A. reduce eddy current losses B. produce a higher power factor C. provide a means for starting D. eliminate arcing between the stator and the rotor

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Description : Which of the following problems will most likely occur if the starting winding of a split-phase induction motor failed to cutout once the motor was in continuous operation? A. The motor will overspeed. B. The ... reduced speed. C. A time delay will stop the motor. D. The winding will burn out.

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Last Answer : Answer: C

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Last Answer : Answer: B

Description : Violent gassing from a lead-acid battery while it is being charged, indicates that the _____________. A. plate separators are grounded B. battery compartment ventilation is inadequate C. electrolyte specific gravity is too low D. charging rate is too high

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Last Answer : If a D.C. motor designed for 40°C ambient temperature is to be used for 50°C ambient temperature, then the motor is to be derated by a factor recommended by manufacturer and select the next higher H.P. motor.

Description : Electric motors intended for use outside the engine room and boiler room are frequently rated to run at a designed ambient temperature of 40°C. What is the equivalent temperature in degrees Fahrenheit? A. 54.2°F B. 72.0°F C. 104.0°F D. 129.6°F

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Last Answer : Answer: A

Description : One function of the movable cams in a drum-type motor controller is to _____________. A. regulate the speed of the motor B. maintain resistance contacts in clean condition C. insulate the operating handle D. limit the amount of load put on the motor

Last Answer : Answer: A

Description : If you obtain a low resistance reading with a megohmmeter connected between terminals 'A' and 'C' of the three-phase, wye-connected winding shown in the illustration, there is __________. EL-0074 A. no open circuit ... 'B' C. an open circuit between 'A' and 'C' D. an open circuit in both windings

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Description : Magnetic controller contacts may become welded together during operation because of _____________. A. excessive magnetic gap B. low contact pressure C. an open coil D. excessive ambient temperature

Last Answer : Answer: B