Answer / tabaraz

starter is used to synchronise the starting current with the requred limit.

Answer / sonu rajput

1) Rotar current is depend upon
1.stator voltage (V1)
2.Leakage reactance of rotar (X2)

2) If ratated voltage is applied to motor ,motor draws heavy current at starting.

3) Hence, to reduce the heavy starting current at the starting of IM starters are used.

Answer / sudhir

T=FLUX*I*POWER FACTOR, as time of starting s=1
so reactance is very large in comperision to
resistance(normaly is very low) for constant load(and
inertia) the power factor(theta=reactance/resistance is
large) is very less(flux is constant) so starting current
is very large so Starter is used to reduce starting current.

Answer / r.siddharth

At the instant of starting, the rotor is stationary, thus
slip being unity, the frequency of the rotor emf equals the
supply frequency and the rotor emf induced per phase is
quite large.

Answer / p k neeraj

at the time of starting of induction motor speed is zero,so
back emf is also zero,as back emf is zero & rotor coil is
sorted(in case of squirrel cage rotor),starting current is
about 5 to 6 times higher then the rated current.so because
of this high voltage drop gets created in the supply line &
equipment connected to this line will experience this.so to
reduce the high current generally we use star delta
starter.at the time of starting we use star connection so
the voltage got reduce then at the time of run we use delta
connection.......
starters also increase the starting torque & improves the
power factor.

Answer / kkkk

starter is for help to when over-voltage coming it will help the motor from destruction

Answer / arun mutharasu

consider a equation ( kvl form in starting period )
V=Eb+IR
at starting time,
the back emf is zero,
so I=V/R,
In case the R is small mean,
eg) v=220 Volt, R=.5 Ohm sub this and get I=440 Amps,
that reason we increase the starting resistance of the
motor using starter.

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