lonewolf454
Member
My superior had the bright idea of replacing a hydraulic motor system with a VFD/motor combo. It is going to be a 3PH/460/50HP motor and PF700 75HP VFD. Problem is in the A-B book it calls for 100A breaker min for 75HP VFD. So I assume I will need not #4 AWG wire to VFD but instead #3. But that is recommended minimum. Per NEC, for 50HP (65FLA) motor, I calculate 81.25 for wire size, (#4) Fuse 113.75 (125A semiconductor) Breaker 162.5 (175A). Now if this breaker is to be 175A per NEC, then will I need to size wire from Breaker to VFD for 175A?
I plan on #4 AWG from VFD to motor, but with larger VFD than needed, questions arise... Any suggestions?
I plan on #4 AWG from VFD to motor, but with larger VFD than needed, questions arise... Any suggestions?