Product Description:

The 09.F4.S3D-3420 is a variable speed drive produced by KEB and belongs to the F4 Combivert Frequency Inverters series. This AC inverter modulates voltage and frequency to regulate the speed of three-phase induction or synchronous motors in small automation cells. By converting fixed mains power into a pulse-width-modulated output, it allows conveyors, pumps, and positioning axes to follow PLC commands with smoother starts, adjustable speed profiles, and reduced mechanical stress.

In operation, the inverter connects to a 3-phase supply within the 400 V class through terminals sized for 1.5 mm² conductors and draws a nominal 4.5 A. A fast overcurrent trip activates at 9 A, while the internal logic permits a short-time 7.4 A surge for acceleration. The output bridge delivers 4.1 A continuously and supplies up to 2.8 kVA of apparent power, matching motors rated at 1.5 kW. Pulse generation occurs at 4 kHz, balancing switching losses with motor acoustic noise. Dynamic braking is supported, and the transistor can conduct 10 A into an external resistor while incoming circuit protection is provided by a 10 A mains fuse. This current and power range suits elevator doors, textile winders, and compact conveyor modules that require stable acceleration and repeatable deceleration.

The unit is intended for enclosed cabinet installation where airflow, conductor routing, and braking components can be managed in a controlled space. The housing carries an IP20 rating, indicating finger-safe openings without gasketed sealing, so placement inside an enclosure is expected. Control boards tolerate ambient moisture up to 95% relative humidity without condensation, and motor leads may extend to 50 m when a shielded cable is used to contain radiated emissions. For repetitive deceleration cycles, the unit can use a 390 Ω braking resistor to absorb regenerated energy and help prevent DC bus overvoltage.