Mitsubishi LD-30FTA Semi-Automatic Tension Controller
The Mitsubishi LD-30FTA is a semi-automatic tension controller designed for web tension management in unwinding, feeding, and winding processes for continuous material processing. This controller calculates and maintains proper material tension based on roll diameter measurement and material thickness input, providing reliable tension regulation for paper, film, foil, textile, and other web materials. The LD-30FTA offers straightforward operation through panel dials and digital switches, making it accessible for operators without extensive programming knowledge while delivering the precision required for consistent product quality.
Tension Control Principle and Diameter Detection Method
The LD-30FTA employs a diameter detection method for tension control. The controller calculates the current roll diameter based on the initial diameter setting and ongoing material thickness accumulation. As material unwinds or winds, the controller adds or subtracts material thickness from the current diameter measurement to compute the instantaneous roll diameter. Tension command output is then adjusted in proportion to the measured diameter, typically following a taper tension profile where tension decreases as roll diameter increases to prevent core crushing or telescoping winding. This semi-automatic approach requires the operator to input initial diameter and material thickness parameters, after which the controller automatically tracks diameter changes during operation.
Power Supply and Output Specifications
The LD-30FTA accepts a wide AC input voltage range of 100 to 240 V AC at 50 or 60 Hz, allowing global deployment without voltage selectors or external transformers. The controller provides an insulated DC output of 24 V at 3.0 A maximum for driving tension control actuators such as powder clutches, powder brakes, or torque motors. This output is isolated from the AC mains supply, improving safety and reducing electrical noise transmission. The output capacity of 3 A is suitable for many industrial tension control applications, including those requiring continuous torque output during extended production runs.
Operating Interface and Parameter Configuration
The front panel of the LD-30FTA provides a straightforward operator interface for setup and monitoring. Digital switches set the initial roll diameter and material thickness parameters. An output ON/OFF key allows the operator to enable or disable the control output during threading, setup, or emergency conditions. Menu selection controls navigate through configuration options, and parameter adjustments are made without requiring external programming tools. The panel includes status indications for power, output enable, and fault conditions. The controller supports both torque control mode, where output is directly proportional to a tension setpoint, and tension control mode, where the controller uses internal PID logic to regulate tension based on feedback from a tension detector. When diameter analog input is used, the maximum diameter and minimum diameter values must be set, followed by a teaching procedure to calibrate the diameter measurement system.
Compatibility with Tension Actuators
The LD-30FTA is designed to interface with a variety of tension control actuators. The output is compatible with powder clutches and powder brakes, which provide smooth, infinitely variable torque control by varying the magnetic field applied to a ferromagnetic powder filling. The controller can also drive air clutches and brakes when used with an appropriate electropneumatic converter. For applications requiring higher torque capacity, the LD-30FTA output can be used as a command signal to a larger power amplifier or torque motor driver. The actuator selection depends on the required tension range, roll weight, line speed, and duty cycle of the application.
Installation and Environmental Requirements
The LD-30FTA is designed for panel-mount installation in a control cabinet. The controller must be protected from dust, oily mist, corrosive gases, and high humidity environments. Operating temperature range is suitable for indoor industrial use. Adequate ventilation space around the controller should be provided to prevent overheating during extended operation. The terminal block connections accept standard industrial wiring sizes, and proper grounding must be provided for electrical safety and noise immunity. Field wiring to the tension actuator should be kept as short as practical to minimize voltage drop, which can affect torque output accuracy.
Typical Applications
Typical applications for the LD-30FTA include paper and cardboard processing machines, film and foil converting lines, textile fabric handling systems, wire and cable manufacturing, printing presses, and slitting and rewinding machinery. The semi-automatic controller is particularly well-suited for processes where material type and thickness change frequently, requiring operators to adjust settings for each new job. The diameter detection method provides stable tension control across the entire roll range, from the core to full roll diameter. For applications requiring direct tension feedback from a load cell sensor, Mitsubishi offers the LE-30CTA series automatic tension controllers, while the LD-30FTA remains the appropriate choice for diameter-based tension control systems.
Integration with Host Control Systems
The LD-30FTA can be integrated into broader machine control systems through its discrete I/O interface. The controller provides a remote output ON/OFF input, allowing the machine PLC or operator station to enable or disable the tension control output. An output remote function is provided that turns the control output on and off in response to external command inputs, giving the remote function priority over the panel ON/OFF switch. This remote integration capability allows the tension controller to be interlocked with machine run signals, emergency stop circuits, and web break detection systems.
Maintenance and Service Life
The LD-30FTA incorporates solid-state electronics with no user-serviceable internal components, providing long service life with minimal maintenance requirements. External fuses protect the output circuit against overload conditions. If the output fuses open due to an actuator overload, they can be replaced after the overload condition has been corrected. Periodic verification of tension calibration using a tension meter or dynamometer is recommended to ensure the controller maintains accurate torque output. The controller's internal power supply is designed for continuous duty and has a typical service life of many years under normal operating conditions.
