NEXT Back List Inquiry , Product Description Series-connection Low-voltage Motor: Parallel-connection Low-voltage Motor Series-connection motor is setting as constant torque. The current will be reduced when the motor is overload. When the current is going up, the RPM is goung down. When the current is going down, the RPM is going up. Vehicle, Rail car, Coiling maching, (Adjust-speed machines). Parallel-connection Low-voltage Motor: Series-connection motor is setting as constant torque. The current will be reduced when the motor is overload. When the current is going up, the RPM is goung down. When the current is going down, the RPM is going up. Vehicle, Rail car, Coiling maching, (Adjust-speed machines). Parallel-connection motor is setting as constant RPM. The torque will be increased when external force is increased, if is constant-speed motor. Constant-RPM machines (Adjust-speep machines) 3KW 24V Shunt /Series motor 1800RPM: 5KW 24V Shunt motor 1800RPM: 7.5KW 48V Series motor 1550RPM: