MICROMASTER 4 commutation choke 200-480V 3AC 186A stand-alone FSF-0.09MH Electrical choke SINAMICS line choke for the compact frequency converter SINAMICS G120, as well as the MICROMASTER 4. Line chokes are used to smooth out voltage peaks or to bridge commutation dips. Line chokes also reduce the effects of harmonics on the converter and the network. If the network impedance is <1%, a line choke must be used to reduce the current peaks. The line choke covers the single-phase voltage range 1AC 200 V to 240 V and the three-phase voltage range 3AC 200 V to 600 V. It is available as a base for frame sizes FSA to FSD and as a stand-alone version for frame size FSF. SINAMICS - simply my drive.