Beckhoff EL9570 EtherCAT Terminal Buffer Capacitor Terminal

Description

Stabilizing the DC bus voltage within an EtherCAT terminal segment is the primary functional role of the Beckhoff EL9570. Operating as a specialized 48 V DC buffer capacitor terminal, this module integrates a high-efficiency 500 µF capacitor designed to absorb regenerative energy and suppress voltage spikes. By mitigating rapid energy feedback from dynamic motor deceleration, it actively safeguards upstream power supplies and adjacent terminal components from overvoltage stress.

Features

• High-Capacity Buffering: Features an integrated 500 µF capacitor designed to temporarily store return energy from dynamic drive systems.
• Dynamic Overvoltage Control: Built-in chopper circuit with an overvoltage control range of ±2 V and a chopper threshold trigger above 56 V.
• Low Internal Resistance: Features less than 20 mΩ internal resistance at 100 kHz, supporting maximum ripple currents of up to 10 A.
• Electrical Isolation: Provides robust 1500 V isolation between the E-bus and the field potential to secure communication lines.
• Compact Housing: Space-saving 12 mm width with integrated status LEDs for real-time diagnostics.

Applications

• Decentralized servo and stepper drive systems experiencing frequent acceleration and braking phases.
• Voltage stabilization in high-density EtherCAT terminal segments.
• Dynamic material handling, packaging machinery, and high-frequency positioning axes.

Technical Specifications

Empirical Engineering Insights

Alternative Models & Compatibility

For all new automation systems and upgrade designs, Beckhoff recommends using the EL9576 buffer capacitor terminal. While the EL9570 is excellent for drop-in maintenance or exact-match replacements in older, validated architectures, the EL9576 offers updated semiconductor profiles and enhanced thermal handling pathways.

Application Pitfalls & Engineering Notes

When implementing the EL9570 in high-inertia motion layouts, remember that its internal storage capacity is 500 µF. If the deceleration profile of your motor returns more energy than this capacity can buffer, the chopper circuit will engage continuously. Under heavy duty cycles, an external, properly rated braking resistor must be wired to prevent localized overheating and subsequent thermal shutdown of the terminal.

Commissioning & Wiring Tips

Ensure wire preparation strictly adheres to the stripping length of 8 to 9 mm. When inserting solid or stranded wires, use a matching flathead terminal tool to depress the spring-actuation tension clamp. For optimal electromagnetic compatibility, route E-bus communication lines separate from high-current power contact paths.

Installation Guidelines