Product Description:

The AX8640-0000-0000 is a multi-axis digital servo drive produced by Beckhoff as part of the AX Digital Servo Drives series. The unit converts three-phase supply voltage into a regulated DC link and then feeds pulse-width-modulated power to connected servo motors. Within an automation cell, it serves as the actuator interface that executes motion commands from TwinCAT or other PLC platforms for synchronized positioning, velocity control, and process tension regulation. Its multi-axis design allows one power section to support coordinated motion tasks across several connected servo channels.

On the line side, the drive draws a rated input current of 35 A AC, yet it can absorb higher demand during acceleration peaks, with branch protection provided by a 50 A device fuse. The shared DC link contains 625 µF of internal capacitance and may be extended to 13,500 µF by parallel modules, while its voltage must remain below 848 VDC during operation. Output capability reaches 40 A DC continuously and 80 A DC for five-second bursts, delivering up to 21.4 kW to the connected motor group. The control electronics use a separate 24 V service line that requires only 120 mA, and the current passed to downstream I/O modules is limited to 20 A. Copper conductors up to 16 mm² can be connected on the mains terminals to carry the thermal load without overheating.

Dynamic braking energy is first absorbed by an internal resistor capable of dissipating 125 W, but applications with heavier inertia can use an external resistor so the drive can dump up to 3.2 kW. Any external resistor must not fall below 18 Ω to prevent excessive current. The short-circuit current rating of 65 kA states the maximum prospective fault current the unit can tolerate when installed with appropriate upstream protection. The braking channel works with the shared DC link to manage regenerated energy during axis deceleration.