Why do motors draw high current during starting?

At standstill, there is no back-EMF (counter-EMF) in the motor, so armature impedance limits current. This results in starting current 5-8 times rated current for induction motors. As motor accelerates, increasing back-EMF reduces the effective voltage across impedance, gradually reducing current to normal running value. This high starting current can cause voltage dips and requires proper starting methods (DOL, star-delta, soft starter, VFD) for large motors.