Description : If the pointer on a megger fails to return to 'zero' when not being used, the _____________. A. megger is out of calibration B. megger is operating normally C. hairsprings are burned out D. pointer probably stuck in that position
Last Answer : Answer: B
Description : A switchboard ammeter indicates a reading slightly above 'zero' when the leads are disconnected, this is caused by _____________. A. mechanical misalignment of the meter pointer B. a poor ground for the meter case C. static electricity in the air D. capacitors inside the meter storing charges
Last Answer : Answer: A
Description : An ammeter reads slightly above 'zero' when its leads are disconnected, this is a result of ___________. A. mechanical misalignment of the meter pointer B. a poor ground for the meter case C. static electricity in the air D. resistors inside the meter storing charges
Description : The illustrated test is being conducted on the motor shown in the illustration, if the lamp lights dimly then ________. EL-0027 A. the bulb needs to be changed to one with a higher wattage rating B. ... D. a ground or partial ground is indicated, a check with a megger should confirm the lamp test
Last Answer : Answer: D
Description : With both ends of a three conductor cable disconnected and arranged without the conductors touching each other, an ohmmeter reading of 'zero' ohms between the ends of one conductor would indicate _____________. A. continuity B. a partial ground C. the resistance is infinite D. a short circuit
Description : When a megohmmeter is being used on a alternating current machine, the meter pointer will dip toward 'zero' and then gradually rise to the true resistance value if the motor insulation is _____________. A. grounded B. good C. shorted D. dirty
Description : When using a multimeter for resistance measurements, it should be calibrated by clipping the loose ends of the leads together and _____________. A. setting the instrument pointer at 'zero' ohms B. ... the plus and minus terminals D. using a special purpose resistance measuring instrument (a bridge)
Description : You are calibrating a multimeter using internal batteries to supply power for resistance measurements. However, you are unable to adjust the pointer to 'zero' using the adjustment knob. Therefore, you should ... change scales to the R X 100 scale and adjust using the 'zero ohms' adjusting knob
Description : A capacitor is to be tested with a megohmmeter. If the meter is connected to a shorted capacitor, the meter pointer should _____________. A. immediately swing to the maximum resistance value ... and gradually decrease D. swing to zero then gradually increase with slight pointer movements down scale
Description : When a megohmmeter is being used to test insulation resistance, current leakage along the surface of the insulation is indicated by the megohmmeter pointer _____________. A. fluctuating around a ... slightly downscale as voltage is applied D. continually rising as the test voltage is applied
Last Answer : Answer: C
Description : When a megohmmeter is used to test the dielectric strength of wire insulation, the initial dip of the pointer toward 'zero' is caused by _____________. A. good insulation B. the leakage of ... of dirty insulation C. the capacitance of the circuit D. the dielectric absorption effect of the insulation
Description : Before measuring an unknown resistance with an ohmmeter, you should _____________. A. adjust the meter's pointer to mid-scale B. short the test leads and calibrate the meter reading to 'zero' C. change the meter's batteries D. center the meter's pointer at infinity
Description : When a megohmmeter is being used to test insulation resistance, current leakage along the surface of the insulation is indicated by the megohmmeter's pointer _____________. A. dipping toward ... kicking slightly down scale as voltage is applied D. fluctuating around a constant resistance reading
Description : A capacitor can be tested using a megohmmeter or an ohmmeter. If the meter is connected to a shorted capacitor, the meter pointer should _____________. A. immediately swing to the maximum resistance ... deflect to and remain at zero D. immediately swing to a high reading and then gradually decrease
Description : Prior to taking a resistance reading with a volt-ohm-milliammeter, the 'zero' setting must be adjusted. After clipping the two leads together, you find the adjustment knob will not return the pointer ... range setting B. weak batteries C. a faulty zero ohms knob D. a faulty meter movement
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 : Discharge switches are often located on hand-driven meggers. The purpose of these switches is to discharge capacitive charges stored in the _____________. A. megger hand generator B. megger movement coils C. tested equipment while conducting test D. tested equipment after testing
Description : A useful instrument for checking A.C. motor performance by measuring possible unbalanced currents is the _____________. A. hand or battery-operated megger B. vibrating-reed frequency meter C. hook-on voltmeter-ammeter D. D'Arsonval iron-vane probe
Description : To determine if a stator coil is grounded, you should use a/an _____________. A. ammeter B. ground detection lamp C. magneto D. megger
Description : As a general rule, the first troubleshooting action to be taken in checking faulty electric control devices is to _____________. A. draw a one line diagram of the circuitry B. test all fuses and measure the line voltage C. take megger readings D. insulate the apparatus from ground
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
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.
Description : Which of the listed conditions could indicate the need for cleaning electrical insulation? A. Low ambient temperature B. Low operating temperature C. High dielectric strength D. Low megger readings
Description : The need for insulation cleaning may be determined by _____. A. visual inspection for dirt accumulation B. high megger readings C. low operating temperature D. the time period since the last cleaning
Description : Electrical machinery insulation will break down more rapidly due to _________________. A. low loading of motors and generators B. frequent megger testing C. high temperatures and vibration D. high operating frequencies
Description : A burned-out LED should be indicated by _____________. A. excessive output B. a slight glow in the crystal C. excessive illumination D. no illumination
Description : When troubleshooting motor controllers, a shorted relay or contactor coil is often indicated by _______________. A. a resistance reading of 'infinity' on an ohmmeter B. charred insulation and/or a blown ... of the coil's leads to ground D. a higher-than-normal voltage reading across the winding
Description : The ground indicating light on the main electrical switchboard is indicating a ground. The best procedure for locating the grounded circuit is to _____________. A. trace the circuit paths while looking for ... a time, until the lights no longer indicate a ground D. check all circuits for continuity
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 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 : 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 : Two AC generators of the same capacity are operating in parallel. One with a zero speed droop setting and the other with a 5% speed droop. If its capacity is not exceeded, the unit whose ... B. maintain the frequency of the system C. have poor sensitivity characteristics D. have poor power response
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
Description : If a magnetic controller relay fails to drop out when the coil voltage is removed from the relay, the probable cause may be _____________. A. excessive spring tension B. overvoltage C. excessive current D. welded contacts
Description : When paralleling two alternators, the synchronizing lamps remain lit as the synchroscope pointer approaches the 0°. This indicates the _____________. A. incoming alternator is running too fast B. alternator ... apart C. synchroscope is defective or broken D. alternator power factors are in phase
Description : If the pointer of the synchroscope is rotating in the slow direction when you are preparing to parallel two alternators, the _____________. A. incoming machine is turning faster than the load alternator B ... alternator is ready to split D. incoming machine is beginning to pick up some of the load
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 : You are attempting to parallel two AC generators and the synchroscope pointer is revolving slowly in the fast direction. You should _____________. A. use the governor control switch to adjust the incoming ... the 0° position D. use the field rheostat to adjust the speed of the incoming machine
Description : Before measuring an unknown resistance with an ohmmeter, you should _____________. A. adjust the meter's pointers to mid-scale B. change the meter's batteries C. center the meter's pointer at infinity D. short the test leads and calibrate the meter
Description : When using a megohmmeter to test insulation, good insulation will be indicated by _____________. A. slight kicks of the needle down scale B. a downward dip followed by a gradual climb to the true resistance ... C. a gradual rise in the pointer reading at the outset D. the initial dip of the pointer
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
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
Description : If an electric motor fails to start, you should FIRST check the _____________. A. phase sequence B. ampere load C. fuse or circuit breaker D. line frequency
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
Description : When a fluorescent lamp fails to light, the trouble can be in the _____________. A. lamp B. starter C. ballast D. all of the above
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
Description : Complete controller maintenance includes _____________. A. periodic testing of protective devices B. checking for loose or worn contacts and weak springs C. maintaining a sufficient supply of spare parts D. all of the above
Description : One diode of a full-wave rectifier has burned out in a shorted condition. Therefore, the output will be ____________. A. zero B. a rectified half-wave C. a rectified full-wave D. equal to the AC input
Description : A full-wave rectifier has one diode burned out in an open condition, what will be the output characteristic of the device? A. Zero B. Half-wave rectified C. Full-wave rectified D. Equal to the AC input