MICROMASTER 4 commutation choke 200V-240V 1AC 3.4A substructure FSA-9.5MH not substructure for V20 Electrical choke SINAMICS Mains choke for SINAMICS V20, as well as for the SINAMICS S110 servo converter, the SINAMICS G110 compact frequency converter and the MICROMASTER 4. Mains chokes are used to smooth out voltage peaks or to bridge commutation dips. Mains chokes also reduce the effects of harmonics on the converter and the mains. If the mains impedance is <1%, a mains choke must be used to reduce the current peaks. The mains 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 substructure for frame sizes FSA to FSD and as a stand-alone version for frame size FSF. SINAMICS - simply my drive.