High-Precision 11kW Motor Drive | SIMOVERT VC 6SE7021-8TB61

Siemens 6SE7021-8TB61 | SIMOVERT MASTERDRIVES VC Frequency Converter

The Siemens 6SE7021-8TB61 is a high-performance frequency inverter from the specialized SIMOVERT MASTERDRIVES Vector Control (VC) series. This unit delivers precise speed and torque regulation for AC induction and synchronous motors in complex industrial setups. Because it utilizes advanced field-oriented vector control technology, it maintains exceptional dynamic performance even under fluctuating load conditions. Engineers typically integrate this 25 Amp converter into central control cabinets to manage medium-power motor applications up to 11 kW. Moreover, the unit provides a stabilized output frequency ranging from 0 to 650 Hz for high-speed machining requirements. This converter remains a critical component for facilities that rely on the proven reliability of the MASTERDRIVES architecture.

Maintaining legacy automation systems requires high-quality hardware that can withstand the rigors of continuous 24/7 manufacturing cycles. This converter includes integrated protection features such as earth fault monitoring and thermal overload safeguards to prevent unexpected downtime. Furthermore, the compact cabinet-mounted design optimizes space while ensuring efficient heat dissipation through an internal air-cooling system. While Siemens has introduced the SINAMICS S120 as the modern successor, the 6SE7021-8TB61 remains an essential spare part. Therefore, sourcing this original inverter is the most cost-effective way to preserve the productivity of your existing industrial drive systems.

Key Features and Functional Benefits

• Advanced Vector Control: It provides superior torque accuracy and speed stability for the most demanding motion control applications.

• Flexible Communication: The unit supports PROFIBUS-DP and serial RS-232/485 interfaces for seamless integration into factory-wide automation networks.

• High-Speed Output: A maximum frequency of 650 Hz allows for the efficient operation of high-speed spindles and motors.

• Comprehensive Self-Protection: Integrated sensors constantly monitor for short circuits, overvoltage, and overtemperature conditions to protect your motor assets.

• Modular System Design: You can easily expand the unit's capabilities with optional technology boards for specialized industrial functions.

Technical Specifications

Typical Applications & System Integration

The 6SE7021-8TB61 is a staple in industries where variable-speed drive control is fundamental to production quality. For instance, it is widely utilized in conveyor systems, industrial printing presses, and plastic extrusion lines for constant torque delivery. In addition, machining centers and large-scale packaging robots rely on this converter for precise positioning and synchronization across multiple axes. Because the module is compatible with the entire SIMOVERT VC ecosystem, it integrates easily with existing Siemens automation software. Consequently, this unit serves as a reliable performance anchor for maintaining the throughput of high-value manufacturing lines.

Frequently Asked Questions (FAQ)

Can I replace this unit with a SINAMICS drive without changing my PLC program?

No, a migration to SINAMICS S120 usually requires hardware changes and modifications to the communication mapping in your PLC.

Does this converter include a PROFIBUS communication board by default?

The 6SE7021-8TB61 is a base unit; communication capabilities depend on the specific option boards installed in the control slots.

What should I check if the drive reports an "Overtemperature" fault?

You should verify that the internal cooling fans are rotating freely and ensure the cabinet ventilation filters are not clogged.

Is this drive suitable for heavy-duty starting loads?

Yes, the vector control method provides high starting torque, making it suitable for heavy-duty applications like crushers or laden conveyors.