Answer / r.c.tiwari

becouse at the time of starting motor take high current
very less duration & over load relay generaly made by
bymatelic contect elements.by matelic element take a time
for heating.so over load rely not trip at the time of
starting.

Answer / ikab

when motor starts high Inrush current flows,
Relays are made smarter/biased to sense this Inrush current
and wait to let this current vanished. Inrush current has 2nd harmonics components and this makes it easy to recognize this current from normal current.

Answer / simon peter

Since the starting I of the motor is high but the tripping value is rated onthe basis of short or earth fault occured.....

Answer / shalini

In a star delta connection, OLR will be placed in the
dealta side.
Starting current would be high during the star connection &
timer will be set to switch over from star to delta.
Once the delta connection is activated, the current would
be naturally less & therby OLR doesnot trip.

Answer / lokesh

As simple one, we are using the starters ( DOL, Star Delta)
liket that for this purpose.

So this starter will help to start the motor with reduced
starting current.

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