Recommended Branch Circuit Protection for VFDs

Recommended Branch Circuit Protection for VFDs

This document (attached) is a supplement to the user manual, where the manuals do not provide detail in the fuse, CB, and manual motor starter (MMS) sizing. This document shows the exact fuses, circuit breakers, and MMS to use on LS VFDs. Equivalent fuses and circuit breakers manufacture can be used. LS has obtained the UL Type E ratings with the MMS units listed for each drive (other manufactures cannot be used). The VFDs covered in this document are the C100, M100, G100, S100, H100 and iS7.  
G100 AC Drive Exception as to the ATTACHED TABLE file named, "LS Electric VFD Bulletin VFD Branch Circuit Protection" at the bottom of this document.  

G100 Exception (IEC):


Note: Only for the LSE G100 AC Drive Can use Class CC, G, J, L, R or T type UL Listed Input Fuse and UL Listed Breaker Only.  Refer to the Table above.  Which also can be found in LSE G100 AC Drive Manual P#302.  

Maximum allowed short short-circuit current at the input power connection is defined in IEC 60439-1 as 100Ka.  Depending on the selected MCCB, the LS VFD's are suitable for use in circuits capable of delivering maximum of 100Ka RMS symmetrical amperes at the drive's maximum rated voltage.