Answer / kj

The main reason for using reduced voltage starters is to
limit the starting current drawn by the motor. This current
can be in excess of 7 times the full load current.

If the current is not limited during starting excessively
large cables must be used and larger transformers etc. to
provide the extra current.

Answer / gopal manda

I would like to explain it by an formula of armature current:
I(Armature)=[V-E(Back EMF)]/R(Armature).
Here "V" is supply voltage and Eb is back emf which is
induced while motor running.If we not decrease starting
voltage the armature current increase very large amount.It
may damage its armature winding and its insulation.Because
at starting of motor RPM is zero so back EMF is also
Zero.That,s why We decrease starting voltage of an induction
motor.

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