Siemens 6SL3210-1KE21-3UP1 SINAMICS G120C Frequency Converter

The Siemens 6SL3210-1KE21-3UP1 is a compact frequency converter from the SINAMICS G120C series. It is designed for simple, space‑saving installation in machine and plant engineering. This unit provides a power rating of 5.5 kW (7.5 HP) for three‑phase 380–480V AC motors. It features an integrated PROFINET interface (2‑port switch) for communication with industrial networks and includes built‑in safety functions (Safe Torque Off – STO). The G120C series is known for its high energy efficiency, ease of commissioning, and robust design.

Electrical Specifications

• Order Number: 6SL3210-1KE21-3UP1

• Rated Power: 5.5 kW (7.5 HP) at 400V 3-phase

• Output Current: 13.2 A (heavy duty), 16.5 A (light duty)

• Input Voltage: 380–480V AC ±10%, 50/60 Hz

• Input Current: 13.7 A typical

• Output Frequency: 0–550 Hz

• Overload Capacity: 150% for 60s (heavy duty)

• Control Methods: V/f, vector control with/without encoder

• Efficiency: > 96% at rated load

• Protection Class: IP20 (UL open type)

• Dimensions (W x H x D): 150mm x 292mm x 211mm

• Weight: 4.2 kg

Integrated PROFINET Communication

The drive includes a dual‑port PROFINET switch (100 Mbps), supporting real‑time (RT) and isochronous real‑time (IRT) communication. It can be integrated into PROFINET IO networks as a device, allowing cyclic process data exchange and acyclic parameter access. The GSDML file is provided for easy configuration in Siemens TIA Portal or other PROFINET controllers. The drive also supports Modbus TCP and can be accessed via a standard web server for diagnostics.

Safety Functions

As standard, the G120C includes “Safe Torque Off” (STO) per EN 61800‑5‑2, certified to SIL 3 / PL e. The STO function can be activated via the built‑in terminal or via PROFIsafe (with appropriate option). No external safety relay is needed for basic STO, reducing cabinet space and cost.

Control and I/O

The drive features 6 digital inputs (24V DC), 2 analog inputs (0‑10V or 4‑20mA), 2 digital outputs (30V DC, 0.5A), and 1 analog output (0‑20mA). An additional relay output (30V DC/250V AC, 2A) is available. All I/Os are electrically isolated. The built‑in PID controller can be used for pressure, flow, or temperature regulation.

Operation and Commissioning

The drive has a basic operator panel (BOP‑2) as an option; the 6SL3210-1KE21-3UP1 is supplied without a panel (order separately or use a PC). Commissioning is performed via the free STARTER software or TIA Portal. The drive supports easy start‑up wizards, automatic motor parameter identification, and application‑specific macros (e.g., conveyor, pump, fan).

Energy Efficiency and Braking

The drive meets IE2 efficiency class (IEC 61800‑9). It includes an integrated energy savings calculator. For dynamic braking, an external braking resistor can be connected to the built‑in braking chopper (internal). DC braking is also available as a standard feature.

Environmental and Compliance

Operating temperature: -10°C to +40°C (derating to 50°C). Storage: -40°C to +70°C. Humidity:<95% non‑condensing. The drive is CE, UL, cUL, and RoHS compliant. It is rated for pollution degree 2 and withstands vibration 0.5g (10–150Hz).

Typical Applications

The G120C is used in conveyors, pumps, fans, compressors, mixers, and extruders in industries such as automotive, food & beverage, and material handling. Its compact size allows direct mounting in motor control centers.

Installation and Wiring

Mount the drive vertically on a flat, non‑combustible surface. Maintain 100mm clearance above and below for airflow. Connect the mains supply to L1, L2, L3 and the motor to U, V, W. Use shielded motor cables and ground the shield at both ends. Connect the control terminals using 0.5‑1.5 mm² wire.

Conclusion

The Siemens 6SL3210-1KE21-3UP1 SINAMICS G120C combines high performance, integrated PROFINET, and safety in a compact footprint, making it a versatile drive for a wide range of industrial applications.