Product Description:

The 18.F4.F1H-3440 is a frequency inverter from KEB in the F4 Combivert Frequency Inverters series. This three-phase AC drive converts fixed input power into a variable output that regulates induction motor speed and torque in automated machinery, conveyors, and processing lines. By modulating voltage and frequency, it supplies controlled motion while protecting motors against overload and line transients during normal operation. The unit fits cabinets where space and thermal limits demand compact power electronics.

The unit uses a supply range designated 400 V-Class and a three-phase input, so the inverter can be wired directly to common plant distribution feeders. Under rated conditions, it draws 55 A from the supply and delivers 50 A on its output side; this current pair reflects conversion losses and helps determine cable sizing. The corresponding apparent power reaches 35 kVA, showing how much power the inverter can exchange with the motor at steady load. A factory-set carrier frequency of 8 kHz balances acoustic noise with switching losses, which are measured as 610 W of power dissipation at full rating. These losses must be removed by panel ventilation to keep semiconductor junctions within safe limits.

The inverter also handles higher transients without damage during rapid load changes. The drive can energize motors up to 22 kW and tolerates a short-time current of 75 A for rapid acceleration. Protective hardware trips at 90 A, while continuous stall operation at 45 A helps prevent winding overheating during heavy starts. Line protection is coordinated with an 80 A input fuse, and the internal IGBTs allow a maximum switching frequency of 16 kHz when acoustic or dynamic demands require finer control. Dynamic braking is supported through an external resistor network; the braking circuit must use at least 13 Ω to keep the braking current under the specified ceiling of 63 A, though a typical value of 20 Ω provides additional thermal margin.