VLT 5352-5552, VLT 6402-6602, VLT8452-8652 For use with frequency inverters manufactured after KW 5/2010 and before KW 16/2016. Frequency inverters. A 176F2153 conversion kit is required on drives manufactured prior to CW 5/2010, but it cannot be used on frequency converters manufactured after manufactured after calendar week 16/2016.