Product Description:

The 18.F4.C1H-3440 is a three-phase frequency inverter produced by KEB within the F4 Combivert Frequency Inverters series. The unit converts fixed mains power into a variable voltage and frequency output so that induction or synchronous motors can be speed-controlled in automated lines, conveyors, and pumps. Its design targets mid-range drives up to 22 kW in general industrial automation. This allows connected equipment to accelerate smoothly, match motor speed to process demand, and maintain stable operation under changing load conditions.

It accepts a supply range of 305 to 500 VAC, covering common 400 V grids while tolerating normal line variation. With a nominal input current of 55 A, the electrical supply can be sized for continuous operation without overstressing upstream components. Internally, the inverter switches at a rated carrier frequency of 8 kHz, which balances audible motor noise and switching losses during routine use. For applications that require quieter motor operation, the carrier frequency can be increased to 16 kHz. When connected to a suitable machine, the drive can power motors up to 22 kW, while providing 35 kVA of apparent output power and 50 A of steady-state output current. It also synchronizes with 50 or 60 Hz line frequency, within a tolerance of ±2%, so it can operate on common industrial power systems.

For process peaks, the inverter tolerates a short-time current of 75 A and supports braking current up to 63 A when an external resistor of at least 13 Ω, with 20 Ω typical, is installed. Overcurrent protection trips at 90 A, and the recommended upstream fuse value is 80 A to protect the supply conductors. The drive dissipates 610 W of heat during operation, so the cooling fan and heat sink must remove that thermal load continuously. The baseplate must remain below 90 °C to avoid thermal derating during sustained use. Adequate airflow across the heat sink helps maintain stable performance during repeated acceleration and braking cycles.