aNerdyEngineer
Member
- Location
- Menomonee Falls, WI, USA
We have applications at times that utilize one VFD for up to 4 motors (overhead cranes). If I branch out the output of the VFD to each motor through thermal overload relays to meet 430.124(C), is there an additional code section that addresses the conductor sizes in this situation? For instance, if I have (4) 25A motors and a 100A VFD output, directly out of the VFD I'd size conductors per that 100A, but I think due to the tap rules, each of the 4 motor branch conductors would also need to be rated for 100A (likely longer than 25' runs per 240.21 and would not meet 240.21(4)). I think if I did size per the 25A on each circuit, I'd need appropriate branch OCPD. Thoughts?