Product Description:

The 21.F4.C0R-2421 inverter is produced by KEB within the F4 Combivert Frequency Inverters series. As a DC-fed variable-speed drive, it interfaces with a central rectifier bus and modulates three-phase motor voltage to match process demands in automated machinery and conveying lines. Its role in industrial automation is to provide controlled torque and speed regulation while supporting stable motor performance across changing load conditions. Because it uses a shared DC link, the unit fits multi-axis systems where regenerated energy can be exchanged between drives instead of being dissipated immediately. This arrangement is useful where several motors accelerate and brake at different times on the same production line.

Electrical sizing is based on the 400 V voltage class, which aligns with standard industrial bus links. At this level, the inverter supplies a continuous output of 90 A, which corresponds to 62 kVA of apparent power for the connected motor group. When paired with a machine requiring up to 45 kW of mechanical output, the drive can sustain that load without derating. Pulse-width modulation is generated at 4 kHz, balancing acoustic noise with semiconductor losses during normal operation. The compact control type combines the logic and power sections in one unit, and the DC input topology supports common-bus energy exchange between multiple axes. Motor leads up to 50 mm² can be clamped at the output terminals, which supports larger cable sets in panel installations.

For brief overloads, the drive tolerates 135 A of short-time current and opens its protection circuit at 162 A to help prevent device or motor damage. Thermal operation is limited by a maximum heat-sink temperature of 90 °C, so cabinet airflow must keep that surface below the permitted threshold during prolonged acceleration cycles. The enclosure has an IP20 rating, which makes the unit suitable for installation inside protected control cabinets rather than exposed machine surfaces. Up to 100 m of shielded motor cable can be used without additional output filters, giving more flexibility when the motor and drive are mounted far apart. Shielding also helps reduce conducted noise on adjacent wiring in larger automation layouts.