07.F4.81D-3420 by KEB

The 07.F4.81D-3420 is a frequency inverter built by KEB for the F4 Combivert Frequency Inverters series. The manufacturer classifies it as a COMBIVERT F4 unit, and it is installed in production lines to regulate the speed of three-phase induction motors using fixed mains supplies, improving process control and energy use. The compact D-size housing allows the drive to fit in tight cabinets, while the integrated braking transistor makes it suitable for axes that require rapid deceleration.

This inverter accepts a three-phase supply in the 400 V class, with a permissible input range of 305 to 500 V. With a nominal input current of 2.8 A, it delivers a nominal output current of 2.6 A and an output power of 1.8 kVA. The design supports motors up to 0.75 kW, and continuous operation at a 4 kHz carrier frequency keeps acoustic noise low. Internal losses reach only 45 W under rated load, limiting heat inside the panel. Fieldbus communication is provided as standard for simple wiring, the line terminals accept 1.5 mm² conductors, and the mains fuse rating should not exceed 10 A. The three inverter phases share a voltage-dependent braking path that can direct up to 5 A into an external resistor rated at no less than 160 ? or into the typical 680 ? element.

Short-term dynamic loads are supported by a 4.6 A surge rating, and an overcurrent trip activates at 5.7 A to protect the power stage. The maximum braking current is limited to 5 A to prevent resistor overload. The heat sink may reach 85 °C, while the unit can operate within an ambient temperature range of -10 to 45 °C. The required tightening torque for the control terminals is 0.5 Nm. The enclosure has an ingress protection rating of IP20, making it suitable for installation in clean electrical rooms. It can operate at a relative humidity of up to 95% without condensation.