Size of conductors based on motor or breaker size?

[rc7288]

I have a 75HP (96 FLA) pump that runs off of a VFD. I'm feeding the pump from a 120A circuit breaker. Should the size of the conductors from the breaker to the VFD be sized for 120A or 96 FLA? What about the size of the conductors from the VFD to pump?

 

[infinity]

The conductors ahead of the VFD are sized based on the input current of the VFD*125%. {430.122}

 

[Jraef]

And from the VFD to the pump, no different than normal.

But, assuming you are using STEEL conduit, I always like to suggest NOT using THHN on the output side of a VFD, use RHH/RHW or XHHW, something that has XLPE (cross linked polyethylene) insulation instead of PVC insulation.

If you are using PVC or anything other than steel conduit, use shielded "VFD cable", and it will have XLPE insulation on the individual conductors.