Product Description:

The 07.F4.81D-3420 is a frequency inverter manufactured by KEB for the F4 Combivert Frequency Inverters series. It accepts three-phase mains power and converts the fixed-frequency input into a variable-frequency output, allowing it to govern the speed of small induction motors used on conveyors, pumps, and compact machine tools. Integration into an automation cabinet is straightforward because the drive supports braking resistors and overcurrent protection, allowing it to manage regenerative energy and stop moving loads when required.

The inverter supplies a nominal output apparent power of 1.8 kVA, which can be delivered continuously to the motor windings. At that rating, the nominal output current is 2.6 A, indicating the steady-state current carried by each output phase. The nominal input current of 2.8 A indicates the load that the upstream feeder must handle during rated operation. The selected motor should not exceed a rated shaft power of 0.75 kW; otherwise, the drive may operate outside its thermal limits. PWM modulation operates at a carrier frequency of 4 kHz, reducing audible noise while limiting switching losses and electromagnetic emissions.

The inverter trips when the output current reaches the overcurrent threshold of 5.7 A. It can support a maximum short-term current of 4.6 A during brief acceleration periods before the protective limit is enforced. Internal power dissipation reaches 45 W at nominal load, and cabinet airflow must remove the resulting heat. Reliable operation requires the heat sink temperature to remain below 85 °C. The recommended supply cable has a cross-sectional area of 1.5 mm² and requires a tightening torque of 0.5 Nm. A 10 A mains fuse protects the three input legs. The braking resistor must have a resistance of at least 160 Ω, while 680 Ω is the typical resistance used to manage deceleration energy.