Synchrounous motor is three phase motor,but its not self
starting .why?
Answer Posted / arnab choudhury
the essential requirement for starting a synchronous machine
is that in the initial stages the rotor( which houses d.c
excited field windings) must be rotated at the synchronous
speed(determined using(120*f)/p where'f'is the supply
frequency and 'p' is the no. of poles) so that the rotor
poles may lock on to the stator rotating poles( created by
three phase balanced excitation given to the stator armature
windings) following which the rotor will rotate
synchronously with stator field at that speed. hence without
the use of an external prime mover in the beginning, the
syn. motor cannot self start....
| Is This Answer Correct ? | 17 Yes | 2 No |
Post New Answer View All Answers
How to reduce -234126219.6403 MVAr generation and by what?
State and define ohm’s law?
Whether it is possible to measure energy at the input of rectifier transformer (12 pulse with very high odd harmonics)
In PFI plant one stage capacitor connection is directly connected(with out megnetic contact controll). but why?
Define what is power quality meter ?
What is meant by Low Resistance Cable and High Resistance Cable.
I have an existing old MCCB. ABB Model SACE, the rating are: Ue = 660 volts, Iu =1250 Amps, 3 poles, Ith (max) =800 amps at 45 deg C. I need a circuit breaker for my 3 phase motors, 380 volts 60 hz. the supplier required the minimum ampacity of the breaker to be 911 amps. can i use this breaker with rating of Iu =1250 amps but Ith = 800amps maximum?
What is the tube exial fan?
Please nybody say, weather the result of Bharat Oman is declared or not? Probable date of declare???????
I had applied for JE in PSEB, Can you pls send me the Question bank for related to my field
What are the application of filter?
how to control dc motor?
If 24 KVA AVR having Input voltage 200-400v, Output voltage 415+-1%, what will be the voltage if Load is 13A.
static chagre
what should be the acceptrd value of winding resistance for 2.5MVA transformer