VFD condutor sizing

[RaulChavez]

Hi, I´m doing the eletrical project for a 300hp belt conveyour motor. It will work wiht a VFD that have to supply 140% of motor start torque. My question is, how can I define the right power conductor for this application since we have 450mt between the MCC and the motor. I´m looking for my options to do this definition, like, type of conductor for this application, and what kind of problems I will have with this operations conditions
thanks!

 

[DickDV]

Use NEC wiring rules same as across the line. If leads are long or voltage drop is a concern, you could upsize the conductors a size or two but you will likely need adaptor lugs for the drive and motor terminals.

 

[ozmosis]

you may need to investigate some form of sinewave or dv/dt filter between the VFD and motor due to the long motor cable length. You should check with the VFD supplier on this. This could have an effect on final output torque if this is critical.

 

[DickDV]

Is that 450 meters from drive to motor? If it is, you will definitely need a motor with the best insulation rating (in North America that would be one with a MG1 Part 31 endorsement) plus probably dv/dt filters. At 300hp, a sine filter for this might just cost as much as the drive!