Product Description:

The 21.F4.C0K-3420 is a frequency inverter manufactured by KEB and assigned to the F4 Combivert Frequency Inverters series. It converts constant-frequency three-phase power into a variable output so that asynchronous motors can be started, stopped, and modulated without mechanical throttling. The device is intended for cabinet installation, where it forms the electrical link between programmable controllers and heavy industrial loads. This arrangement enables precise speed regulation and energy-efficient operation across conveyor, pump, and processing equipment.

The drive is designed for a 400 V mains category and accepts a three-phase supply through conductors up to 50 mm² in cross-section. During continuous production, the input section draws a nominal current of 100 A, while the inverter can deliver a steady output of 90 A to the motor terminals. The corresponding apparent power reaches 62 kVA, providing headroom for torque peaks that occur during closed-loop vector control. Carrier pulses are modulated at 4 kHz, a switching frequency that balances acoustic noise with semiconductor losses. Protective coordination uses a maximum 160 A mains fuse, and an overcurrent trip is set at 162 A to disconnect the unit before semiconductor damage occurs. Dynamic stopping energy can be dissipated through a 10 Ω braking resistor, and the unit can operate at up to 95% relative humidity.

The power stage can run motors rated up to 45 kW, covering medium-sized axial fans, mixers, and extruders. For brief overloads, the current limit rises to 135 A, allowing acceleration of high-inertia loads without triggering the main trip level. The housing has an ingress protection rating of IP20, so installation inside a guarded enclosure is required to prevent contact with live parts. The climatic category is 3K3, indicating suitability for clean, ventilated control rooms without condensation or corrosive contamination.