Machine grounding

I’m trying to fill out the forms to get a tech out to set up the machine and I’m just seeing some requirements that I don’t meet but can be fixed if necessary.

Haas says the ground needs to be the same size as the incoming wires. Right as it sits I have three #3 for input and the ground wire is #6.
Is that not good?

If not can someone explain why the ground and line need to be the same size?

And layman’s term what do you consider a dedicated ground?

I have 2 hots and a neutral to my sub panel at shop and then from there to phase perfect to disconnect to machine it’s grounded. So I’m grounded back to neutral of main box and shop building. That sounds good to me but I’m no electrician and everyone I’ve talked to are not familiar with phase perfect or cnc machines and they are not comfortable working on it.
Does any of that sound wrong?

I normally pull all my wires in metallic conduit with a bare ground wire to the local disconnect at the machine that home runs back to the main service disconnect. The NEC will tell you what size ground is code for a particular ampacity panel.

The trunking to the machine gets a second ground wire. Now having said that CNC machines typically want a low impedance ground not for safety but for noise. IF the HAAS tech wants #3 you're likely going to have to pull in a #3 for them to warranty their work.

All my wires are pulled through emt but my grounds are not bare.
I think the #6 ground is the only thing holding me back so I guess it’s better to be safe than sorry and I will pull a 3 through from the machine back to PP.

Not an electrician by trade but...

NEC requires safety ground to be same size as supply lines to insure the current carrying capability of the safety ground is same as supply so it can handle the fault current to trip the breaker.

However, at some gauge of current feeders the safety ground may be reduced.

Best to seek guidance of your local building inspector.

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Neutral is not ground. Confusing for sure as it seems bonded to the same
What you see in size is how to not end up in lawsuit.
Bob

(Not an electrician by trade but...) I am... The NEC does NOT require the ground wire to be the same SIZE as the load conductors. The NEC does have requirements for ground size bases on amps of feeder, but that only there to trip the breaker and shut things down with out melting the ground wire....Phil

Yeah the same size ground had me wondering why but no problems bc the haas guy opened the back panel took his readings and set it up no problem. Even said for not being an electrician it looked good. He said he’s seen where certified electricians didn’t do nearly as neat a job. I guess when you are doing the work for yourself or you just care what your work looks like bc that’s how people judge you, you do the best job you can. Not bragging at all but was extremely relieved to hear that and I think I even patted myself on the back lol. Just joking