Description : An alternator switchboard has a synchroscope and synchronizing lamps. If the synchroscope is broken, which of the steps listed is the most essential before an alternator can be paralleled with the bus? ... D. A portable phase sequence indicator must be used to verify the information from the lamps.
Last Answer : Answer: C
Description : A diesel driven emergency generator is prevented from being paralleled with the ship's service generators by __________. A. an electrical interlock system B. an automatic paralleling trip switch C. the synchronizing oscilloscope D. the reverse current relay
Last Answer : Answer: A
Description : Attempting to parallel an AC generator which is out of phase with the bus will result in which of the following problems? A. The breaker should trip. B. The KVA will decrease. C. The synchronizing lamps will burn out. D. The power factor will be unitized.
Description : A current-carrying conductor makes accidental contact with a wiring conduit. This will be indicated by a _____________. A. low switchboard wattmeter reading B. high switchboard wattmeter reading C. darkened switchboard ground detecting lamp D. darkened switchboard synchronizing lamps
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 : When paralleling two alternators the synchronizing lamps grow dim and are totally darkened as the synchroscope pointer approaches the 0° position. This indicates the ____________. A. alternator voltages ... alternator is in phase with the bus voltage D. synchroscope pointer is defective or broken
Description : When paralleling two alternators using three synchronizing lamps, the flickering of all three lamps becomes progressively slower and slower. This means the ______________. A. frequency of the incoming ... the bus D. terminal voltage of the incoming alternator is approaching that of 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
Last Answer : Answer: B
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
Last Answer : Answer: D
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
Description : While paralleling two (2) AC generators using synchronizing lamps only, both lamps will go dark when the generators are ____________. A. running at the same speed B. grounded C. of the same polarity D. in phase
Description : The voltage of an operating AC turbogenerator is raised or lowered by adjusting the _____________. A. exciter generator governor controls B. synchronizing switch C. phase sequence switch D. generator field exciter
Description : As shown in the illustrations, feedback or rudder angle repeatback is used by the steering stand in which operational modes? EL-0097 A. Gyro-compass and hand steering only B. Hand steering and non-followup only C. Non-followup and gyro-compass only D. Gyro-compass and synchronizing only
Description : How synchronoscope is used for synchronizing Alternators?
Last Answer : Synchronoscope can be used for permanently connected Alternators where the correctness of phase sequence is already checked by other means. The rotation of pointer is proportional to the difference in ... alternator is running slow. If the difference in frequency is large the pointer will oscillate
Description : What are the advantages and disadvantages of three dark lamps method of synchronizing?
Last Answer : Advantages: · The synchronous switch using lamps is inexpensive · Checking for correctness of the phase sequence can be obtained in a simple manner which is essential especially when the Alternator ... The frequency of the incoming Alternator in relation to the bus-bar frequency is not available.
Description : What is synchronizing?
Last Answer : The operation of connecting an alternator in parallel with another alternator or with common bus bars is known as synchronizing.
Description : What are the settings provided in synchronizing scheme (SKE Relay)?
Last Answer : Voltage – V1- V2 = 10% Frequency – t = 0.05 Sec (2.5 Hz) % Slip – 0.45 Phase angle difference - 20°.
Description : Why synchronizing scheme has been adopted? What are interlocks provided?
Last Answer : To check running and incoming buses, which are going to be interconnected are in synchronism with each other. Interlocks 1. Synch selector. 2. Only one breaker can operate at a time. 3. ... will bypass this synch contact). Bypass facility is provided to close the breaker on dead bus only.
Description : Synchronizing iCal to Google Calendar?
Last Answer : get on http://Digg.com they have an article talking about how you can do it. Just search iCal.
Description : How would one squeeze more channels of communication into TDM frames of standard length? A. Shorten the time delay for each channel B. Raise the amplitude C. Add modulators D. Remove the synchronizing pulses
Last Answer : A. Shorten the time delay for each channel
Description : The process of converting analog signals into digital signals so they can be processed by a receiving computer is referred to as: a. modulation b. demodulation c. synchronizing d. digitising
Last Answer : digitising
Description : The process of converting analog signals into digital signals so they can be processed by a receiving computer is referred to as a. modulation b. demodulation c. synchronizing d. Digitizing
Last Answer : b. demodulation
Description : What is the purpose of a synchronizing network in a servo system?
Last Answer : To switch control of the amplifier between either the coarse signal and the fine error signal.
Description : After a black out the emergency generator comes on; On restoring the main supply we are closing the circuit breaker of the main generator without bothering about synchronizing. How is this possible?
Last Answer : There is a power link connection breaker between the main generator and the emergency generator. During black out, this breaker trips. The emergency generator starts and its breaker closes and feeds only ... , there is no paralleling between main and emergency generator. Ask E/O for more details.
Description : What is dark lamp and bright lamp method for synchronizing? How is the connection made?
Last Answer : Formerly, three light bulbs were connected between the generator terminals and the system terminals. As the generator speed changes, the lights will rise and fall in intensity at a rate proportional to ... to the system may be closed and the generator will then stay in synchronism with the system.
Description : ____________ carries signalling and synchronizing commands. a) Traffic channels b) Control channels c) Signalling channels d) Forward channels
Last Answer : b) Control channels
Description : why equalizing pulses are needed. Draw the vertical synchronizing pulse structure.
Last Answer : The ½ line difference just prior to the start of serrated vertical pulse does not affect the horizontal deflection synchronization but it does affect the vertical synchronization and the interlaced scanning. The ... the vertical sync pulse to occur at the correct time after every field.
Description : Which of the methods listed is used to maintain the division of load between two compound-wound, DC generators operating in parallel? A. The shunt fields are interconnected. B. The shunt ... generators are connected in series. D. The equalizer connection parallels the series fields of all machines.
Description : Which of the methods listed is used to start a AC generator turning? A. Residual magnetism remaining in the field poles. B. Residual magnetism remaining in the field coils. C. Residual magnetism remaining in the armature. D. Rotation by a mechanical prime mover.
Description : Under normal conditions, storage batteries used for starting the emergency diesel generator are maintained in a charged state by which of the following methods? A. Trickle charging B. Fast charging C. Equalizing charge D. Reverse charging
Description : The operator of electrical motors should keep a constant check on the loads they carry because _____________. A. low loads necessitate frequent insulation cleaning B. exceeding nameplate values shortens ... wasted if full loading is not utilized D. power factor correction methods are load dependent
Description : Which of the following methods should be used to test for an 'open' coil in an AC motor stator? A. Test with an ohmmeter, one test lead on the shaft, and the other test lead to the stator leads ... an open coil. D. Use a growler, listening for noise and vibration to increase when over an open coil.
Description : Which of the following methods should be used to dress the face of silver-plated contacts? A. Filing B. Burnishing C. Sanding with 0000 sandpaper D. All of the above are correct.
Description : Which of the methods listed is used to maintain equal load sharing between two compound wound DC generators operating in parallel? A. The shunt fields are interconnected. B. The shunt field rheostats ... are connected in series. D. The series fields of both generators are connected in parallel.
Description : Methods to control speed of Wound Rotor Motors?
Last Answer : The speed of wound rotor motors are changed by changing the slip of the motor. This can be achieved by: Varying the stator line voltage Varying the resistance in the rotor circuit Inserting and varying a foreign voltage source in the rotor circuit
Description : What are methods available for making single phase induction motor a self starting?
Last Answer : By slitting the single phase, by providing shading coil in the poles.
Description : What are the two methods of control in ac voltage controllers?
Last Answer : a. ON-OFF control b. Phase control
Description : What are the methods of reduction of harmonic content?
Last Answer : a. Transformer connections b. Sinusoidal PWM c. Multiple commutation in each cycle d. Stepped wave inverters
Description : What are the different methods of firing circuits for line commutated converter?
Last Answer : a. UJT firing circuit. b. The cosine wave crossing pulse timing control. c. Digital firing schemes.
Description : What are the different methods to turn on the thyristor?
Last Answer : a. Forward voltage triggering b. Gate triggering c. dv/dt triggering d. Temperature triggering e. Light triggering
Description : What are the different turn on methods of SCR?
Last Answer : Forward voltage triggering Gate Triggering dv/dt triggering Temperature triggering Light triggering
Description : What are the methods of checking the phase difference?
Last Answer : 1. All Dark lamp method 2. Two bright one dark lamp method 3. Synchroscope
Description : Name the various methods for predetermining the voltage regulation of 3-phase Alternator.
Last Answer : The following are the three methods which are used to predetermine the voltage regulation of smooth cylindrical type Alternators · Synchronous impedance / EMF method · Ampere-turn / MMF method · Potier / ZPF method
Description : List some methods of cooling of transformers.
Last Answer : A:Air natural, Air blast, Oil Natural, Oil natural air forced, Oil natural water forced, Oil forced, Oil forced air natural, Oil forced air natural, Oil forced water forced.
Description : What are the methods adopted to reduce harmonic torques?
Last Answer : The methods used for reduction or elimination of harmonic torques are chording, integral slot winding, skewing and increasing the length of air gap.
Description : List out the methods to improve the power factor of the induction motor.
Last Answer : The power factor of the induction motor can be improved by reducing the magnetizing current and leakage reactance. The magnetizing current can be reduced by reducing the length of air gap. The ... stator & rotor slots, by providing short chorded winding and reducing the overhang in stator winding.
Description : List out the methods of speed control of cage type 3-phase induction motor?
Last Answer : a) By changing supply frequency b) By changing the number of poles c) By operating two motors in cascade
Description : What are the methods for determining depreciation charges?
Last Answer : The decrease in the value of the power plant equipment and building due to constant use is known as depreciation. The cost of depreciation will depend on the size and type of equipment ... equals the cost of equipment. The methods commonly used for determination of annual depreciation charges are
Description : What are the advantages of synthetic testing methods?
Last Answer : The breaker can be tested for desired transient recovery voltage and RRRV. Both test current and test voltage can be independently varied. This gives flexibility to the test The method is simple With ... capacity (MVA) of five time of that of the capacity of the test plant can be tested.
Description : What are the indirect methods of circuit breaker testing?
Last Answer : o Unit test o Synthetic test o Substitution testing o Compensation testing o Capacitance testing