Product Description:

The 09.F4.S3D-1220 is a frequency inverter produced by KEB within the F4 Combivert Frequency Inverters series. Designed for motor speed regulation in industrial automation, the unit rectifies incoming AC and provides a variable-frequency, variable-voltage output so asynchronous or synchronous machines can follow process demands. Integrated control terminals and a compact enclosure facilitate panel installation where programmable acceleration, deceleration, and torque control must be delivered from a single-phase supply.

Electrical ratings describe how the inverter interfaces with the mains and the driven motor. It belongs to the 230 V voltage class and accepts a single-phase supply; at nominal load, the input current reaches 14 A. Internally, the power stage converts this to an output that can deliver 2.8 kVA of apparent power and a continuous motor current of 7 A. These figures align with a rated mechanical load of 1.5 kW, giving adequate headroom for standard 4-pole motors. Pulse-width modulation is performed at 4 kHz, a switching frequency chosen to limit acoustic noise while keeping transistor losses under control. For wiring, the recommended line conductor cross section is 2.5 mm², and the control section offers a digital I/O supply of 15 V for sensors or relays.

The inverter should be protected by a 20 A mains fuse, and its electronic overcurrent trip activates at 15 A on the DC link. For overload events, it can provide 12.6 A short-time current, while the braking chopper conducts up to 7 A into an external resistor network. Energy dissipation requires at least 56 Ω but is optimized with a 100 Ω typical resistor, ensuring thermal limits are not exceeded. During normal operation, the power electronics dissipate 70 W, heat that must be removed by panel airflow to maintain reliability.