LE7-40GU-L Tension Controller Brand New LE740GUL

The Mitsubishi Electric LE7-40GU-L is a specialized tension controller designed for maintaining precise, constant tension in continuous strip materials such as paper, film, foil, textile, wire, or sheet metal as they move through processing machinery at varying speeds.

This closed-loop regulator automates critical web tension control, eliminating the need for constant operator intervention and ensuring consistent material handling that manual adjustments cannot achieve.

As the successor to Mitsubishi's LE-40MT and LE-30CT series, the LE7-40GU-L features direct physical compatibility for easy retrofitting while introducing significant improvements including a 3.8-inch touch panel LCD with multilingual support (English, Japanese, Simplified Chinese).

The LE7-40GU-L adapts to three distinct machine positions with specialized control strategies:

• Unwinding (pay-off reel): Compensates for decreasing reel diameter by adjusting brake torque to maintain constant tension from full diameter to core
• Intermediate shaft: Controls tension in processing zones using servo motors in torque mode to decouple tension variations between adjacent sections
• Winding: Progressively adjusts winding motor torque as roll diameter increases to maintain constant web tension throughout the complete winding cycle

Each tension zone requires a separate controller, with multiple units networked via CC-Link or Ethernet for coordinated control in complex systems.

The LE7-40GU-L integrates the power amplifier directly into the controller housing, eliminating the need for separate amplifier modules in DC 24V systems. This compact integration reduces panel space, simplifies wiring, and minimizes spare parts requirements.

For pneumatic systems, the controller provides 4-20mA control signals to electro-pneumatic regulators, while servo motor applications utilize torque command voltage outputs to servo amplifier reference inputs.

With the optional LE7-DCA reel diameter calculation unit, the controller supports:

• Open-loop control: Computes actuator torque based on tension setpoint, reel diameter, and line speed without tension detector feedback
• Feedforward/feedback composite control: Combines anticipatory open-loop calculation with accurate feedback correction for superior response to changing conditions

The controller is designed to work with Mitsubishi Electric's LX7-F, LX-TD, and LX-TD-928 series tension detectors. Third-party detectors with compatible output signal ranges may be used with careful signal level verification.

Yes, the controller natively supports CC-Link IE Field Network Basic communication over standard Ethernet hardware, operating as a slave station for monitoring tension values, reading status, and controlling setpoints.

Upon detecting signal loss, the controller transitions to a configured safe operating mode, generates alarm indications, and can trigger emergency stops if required for machine protection.

The LE7-40GU-L uses spring-clamp terminals instead of screw terminals and provides transistor outputs rather than relay contacts, requiring adaptation of external circuit wiring during replacement.

No, each LE7-40GU-L controls a single tension zone. Machines with multiple zones require separate controllers networked for coordinated operation.