for enabling discrimination of whether or not a blower motor is in a locked state to be conducted promptly and reliably irrespective of the motor speed , a blower system comprises a discrimination circuit for discriminating whether or not the blower motor is in a locked state based on change in the position of the rotor of the motor , and the discriminating time period between motor locking and output of a discrimination signal is determined to be shorter for a higher set rotational speed of the motor in response to the speed setting operation of a motor speed setting device .