3 Phase Iron Core Chokes are requires for drives to restrict dv/dt to allowable limits for electronic circuit. Step-Up manufactures these type of Chokes upto 4000 Amps. Chokes are diminished for voltage drop specified by the drive manufacturer. In some cases chokes are also required on output side of chokes. The same are manufactured as per specifications of the client. In some cases Air Cored Chokes are necessary. Step-Up manufactures Air Core Chokes 1Ph & 3Ph upto 4000 Amps rating / Maximum 11 KV.