What is synchroscope?

1 Answer

Answer :

Synchroscope is an instrument, which shows the phase relationship of emf of the incoming alternator and at the same time it also indicates whether it is running slow or fast. This instrument works on the principle of rotating magnetic fields. It consists of a small motor with rotor and stator. Both wound for two phase. A potential transformer connected to two of the main bus-bar give supply to the stator ‘A’ winding and another potential transformer of same type connected to the corresponding terminals on the incoming machine supply to the stator ‘B’ winding. The rotor rotates if the stator resultant flux in the ‘A’ and ‘B’ is different and the exact time of synchronizing is the stand still position of the rotor. That means the both the voltages in winding ‘A’ and ‘B’ are same and there is no resultant flux to rotate the rotor. The speed of the rotor depends on the frequency of the alternator and is too fast when alternator (incoming machine) speed is more and less when alternator is too slow.

Related questions

Description : Which of the synchroscope illustrations depicts the appropriate direction of rotation and position for closing the circuit breaker when paralleling AC generators? EL-0053 A. A B. B C. C D. D

Last Answer : Answer: D

Description : As shown in the illustration, which of the listed actions of the synchroscope pointer is occurring? EL-0002 A. Revolving slowly in the slow direction. B. Revolving rapidly in the slow direction. C. ... stationary at the 12 o'clock position since the leading edges of the A phases are in phase.

Last Answer : Answer: C

Description : When two AC generators are being paralleled, the breaker should be closed with the synchroscope pointer rotating in the ____________. A. 'slow' direction, just before the 12 o'clock position B. 'fast' ... just before the 12 o'clock position D. 'slow' direction, just after the 12 o'clock position

Last Answer : Answer: C

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

Last Answer : Answer: C

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

Last Answer : Answer: C

Description : When paralleling two AC generators, the synchroscope selector switch and frequency meter switch should be set up to sense the frequency of the _____________. A. bus B. generator on the line C. oncoming generator D. bus transfer relay

Last Answer : Answer: C

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

Last Answer : Answer: B

Description : The RPM of an AC generator can be measured with a/an _____________. A. ammeter B. voltmeter C. vibrating reed meter D. synchroscope

Last Answer : Answer: C

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 : 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

Last Answer : Answer: A

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

Last Answer : Answer: C

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

Last Answer : Answer: A

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

Last Answer : Answer: B

Description : You are attempting to parallel two AC generators and the synchroscope pointer stops at a position other than 0° prior to closing the circuit breaker. This indicates ___________. A. the frequency of ... be closed after breaker has been reset D. there is an existing cross current between generators

Last Answer : Answer: A

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

Last Answer : Answer: B

Description : Hand-portable phase sequence indicators should be used when ____________. A. installing a new synchroscope B. preparing to make the shore power connection C. replacing a defective solenoid D. all of the above

Last Answer : Answer: B

Description : Why synchroscope method is more better compared to others?

Last Answer : It is very accurate as it doesnot require personal judgement

Description : What is a synchroscope?

Last Answer : Synchroscope is an instrument, which shows the phase relationship of emf of the incoming alternator. It also indicates whether the incoming alternator is running slow or fast.

Description : What does different position of the synchroscope needle mean; what is the difference between 6 o clock and 12 clock?

Last Answer : 6 o’clock means that out of synchronisation. We cannot parallel the incoming generator. 12 o’clock means the perfect synchronised condition (voltage, frequency and phase sequence match).

Description : State the use of synchroscope.

Last Answer : Use of Synchroscope: The synchroscope is used to determine the exact instant of switching required to connect the alternators in parallel or put an alternator in parallel with the infinite bus. ... idea of the faster or slower machine to make adjustments in speed of alternators for synchronising.

Description : With neat sketch explain working of Weston type synchroscope.

Last Answer : Weston type synchroscope:  Working: It consists of three limbed transformer. The winding on one of the outer limbs is excited from bus- bars and that on other limb by incoming machine. The two fluxes ... the lamp is flickering at a very much slow rate and it is at its maximum brightness.