grounding wire size to VFD input

[TMMB]

I would like to know how i can sizing the grounding wire conductors included in VFD cables, the cable is 6 cores, 3 for power & another 3 for grounding
how I can sizing the grounding wires

 

[herding_cats]

Not sure I'm getting the question right. What is the size of the drive? What amperage is it rated for? If such wires are included, what size are they now?

 

[ptonsparky]

I think he wants to size a single EGC in the feed to the VFD, that is equivalent to the three that are in the cable to the motor.

 

[ptonsparky]

Or maybe the other way around...

 

[infinity]

Not something we typically use here in the US but permitted by the NEC.

250.122 Size of Equipment Grounding Conductors.
250.122(A) General.
Copper, aluminum, or copper-clad aluminum equipment grounding conductors of the wire type shall not be smaller than shown in Table 250.122. The equipment grounding conductor shall not be required to be larger than the circuit conductors supplying the equipment. If a cable tray, a raceway, or a cable armor or sheath is used as the equipment grounding conductor, as provided in 250.118 and 250.134(1), it shall comply with 250.4(A)(5) or (B)(4). Equipment grounding conductors shall be permitted to be sectioned within a multiconductor cable, provided the combined circular mil area complies with Table 250.122.

 

[TMMB]

Not sure I'm getting the question right. What is the size of the drive? What amperage is it rated for? If such wires are included, what size are they now?

VFD drive for motor 60 HP, 400V, 3 Ph , the VFD cable (6 cores), 3 for power and 3 for grounding
i Know how to size the 3 core of the power, my Q is , how to size the 3 cores of the grounding

 

[infinity]

VFD drive for motor 60 HP, 400V, 3 Ph , the VFD cable (6 cores), 3 for power and 3 for grounding
i Know how to size the 3 core of the power, my Q is , how to size the 3 cores of the grounding

The answer is in the code section in post #5.

 

[ptonsparky]

Based on #8 EG for 100 Amp OC protection ahead of the drive.
#8 = 16510 cm
16510/3=5503
#14 is too small at 4110,
#12 would work.

 

[don_resqcapt19]

how to size the 3 cores of the grounding

In general, the equipment grounding conductors installed by the manufacturer in the cable are of suitable size unless you have cables installed in parallel. The sizing selected by the manufacture will meet the code requirements,

 

[ptonsparky]

In general, the equipment grounding conductors installed by the manufacturer in the cable are of suitable size unless you have cables installed in parallel. The sizing selected by the manufacture will meet the code requirements,

I had never worried about it the few times I used it.