Patent ID: 8487561

Claim:
Soft starter device which is adapted to be connected to an electric motor (M) and to a power supply, the soft starter device ( 1 ) comprising an electrical current limiting means ( 2 , 4 , S 11 ) adapted to limit the electric current supplied to the motor (M) to a preset maximum current limit, a ramp-up time determination means ( 3 A, 3 B, 4 ) adapted to determine the actual ramp-up time of the electric motor (M), said actual ramp-up time being the time which has been required by the motor to reach a final rotational speed starting from zero, a storing means ( 6 , 4 , S 10 ) adapted to store a preset reference ramp-up time, a comparing means ( 4 , S 17 ) adapted to compare the determined actual ramp-up time with said preset reference ramp-up time, a replacing means ( 4 , S 18 ) adapted to replace said preset maximum current limit by auto-adjusting said preset current limit with a lower/higher current limit depending on said determined actual ramp-up time.