Is VFD cable ground conductor current carrying conductor?

[PaulBr]

Is ground conductor in VFD cable carrying current? Do we need to count this conductor for derating purpose?
NEC states that in 4 wires Y system, when non linear load with a harmonic currents, neutral conductor needs to be counted as current carrying conductor.
VFD is not 4 wire system but it source of harmonic currents.It seems that in all VFD cables I have seen ground conductor is the same gage as motor conductors.
Are there current in ground conductor of VFD cable during normal operation (no short between phase and ground)?

PaulBr.

 

[davidbeach]

By NEC definition, no there is no current. That doesn't mean that an ammeter won't tell you differently, but for counting current carrying conductors, per the NEC, no.