A.C. motors should be designed for direct on-line starting. They should be capable of being switched on without damage to an infinite bus bar at 110% of the nominal voltage with an inherent residual voltage of 100% even in phase opposition. For starting the motors from the individual main and auxiliary bus bars, a momentary voltage drop of 20% referred to nominal voltage should be taken into consideration. With 85% of the nominal voltage applied to the motor terminals, each motor should be capable of accelerating its associated load to full speed with a minimum accelerating torque of 5% of full load torque.