Answer Posted / satya
a synchronous motor is not self starting.
when three phase current displaced in time by 120 degree is
applied to the three phase stator windings displaced in
space by 120 degree then a rotaing magnetic field is
produced in the air gap. the rotor tends to allign with this
rotating field. the rotor windings are supplied by dc . so
consatnt poles are produced on the rotor.
now suppose the instant when the rotating stator field has
its north pole in line with the south pole of the rotor. the
rotor will be attracted and tend to move with the stator.
but due to its inertia before it starts to move with the
stator the south pole of the stator comes in line with the
rotor south pole. so now the rotor gets repelling force and
it tends to move in the opposite direction as that of the
stator. but again before it starts to move the stator north
pole comes in line with the rotor south pole. thus overall
the efect is that the syn. motor is not self starting. once
it is brought to the syn speed by an external primemover it
rotates at syn. speed irrespective of the load.
| Is This Answer Correct ? | 50 Yes | 2 No |
Post New Answer View All Answers
what is the AC Plant and how can do the work with parts and picture tell us 150 Tr
Where burned of electricity,when,who, & why.
sir i used 3 hp of motor for spraying pump, other home light and other home items which size of allminium pvc wire ix used
How LT megger works ?
what is relation between ct and pt ratio with multiplication factor of a energy meter? is there any other factor on which multification factor depend?
how oltc works in rectiformers of higher rating (27 mva,200v dc,120kamps) please provide me full information with diaggram.
use of choke in APFC panels
description about dry type transformers
It is desired to flood light the front of a building 42 meters wide and 16 meters hig.Projectors of 30 degree beam spread and 1000 watt lamps giving 20 lumen/watt are availabl.If the desired level of illumination is 75 lumen/m and show a suitable scheme.Assume the cofficient of utilization, deprecitation factor and waste light factor are 0.4, 13 and 1.2 respectively.
WHY THE RATINGS OF THE TRANSFORMER IS 33KV WHY NOT OTHER???
in star-delta tranformer,if the input of star connection is 400/7v 3 kva then what is the output of delta connection?
what is RFCT and Insulgard Relay & It's function?
11 kV line deraction check by an Engineer.
Dear friends, i would like to know that what is the exact function of 'exciter winding' & 'aux winding' in Alternator?
what is the string efficiency
