Answer / jeyapandian

always a motor takes starting current is hihg(5 or 6 times
full load current).
bcz,
I=V-E/r
at starting E=0,
so I=V/R
I is max.
at running , E has some value.so I decreses.

Answer / don

in squriell cage induction motor the rotor bars are short
circuted it cannot having additional resistance to maintain
the torque.thats why the induction motor takes 5 to 6 times
full load current. but slip ring induction motor we connect
rheostat (resistance) in starting it take normal current.

Answer / dharababu

IN MOTORS THE EQUATION FOR BACK EMF IS GIVEN BY
Eb=V-IR,
SO ARMATURE CURRENT I=V-E/R
AT THE TIME OF STARTING THE STATOR FLUX WHICH PRODUCES BY
SUPPLY,WILL NOT LINK WITH ROTOR AND THERE IS NO BACK EMF
PRODUCES IN ROTOR I.E I=V/R.

AS THE RESISTANCE OF ROTOR WILL BE VERY SMALL , THE
STARTING CURRENT WILL BE VERY HIGH .

Answer / ram

starting position is motor both through the (2.5-5)full
load current.in the motor starter is used in limit the
starting currnt. I=V-E/r

Answer / dipak sonkusare

Stator winding resistance is very less and emf induced at
starting (E) = 0. As V=IR so I=V-E/R... i.e. Ist is very
high.

After (10min) starting and during running, E increases
gradually which decreses the running current (Ir).

Hence starting current is always more more (5-6times) the
rated / running current of motor.

Answer / mohamed said

starting current is the ccrrent that the motor need to
satart = (2.5-7)Ir
running current is the current that the moto neede when it
loaded
ideal current is the rating current

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