Grounding of CNC machines???

[Kyell]

Hello,
I have a question, while I do not fully believe what I am seeking is a NEC reference, it may be something said in a CD from Mike Holt.
the reference is to a ground rod at each CNC Machine or to building ground. I BELIEVE it was said, " this ground rod was both not needed and determental to the functioning of the machine. Please refresh my memory.

Professionally,
Bob

 

[kwired]

There is no NEC requirement to use such a ground rod. There is no NEC prohibition to using one either.

A seemingly common misunderstanding when such rods are requested by equipment instructions is to use a rod in place of an equipment grounding conductor. That is a NEC violation and creates potential shock hazards.

 

[electricguy61]

Hello,
I have a question, while I do not fully believe what I am seeking is a NEC reference, it may be something said in a CD from Mike Holt.
the reference is to a ground rod at each CNC Machine or to building ground. I BELIEVE it was said, " this ground rod was both not needed and determental to the functioning of the machine. Please refresh my memory.

Professionally,
Bob

I'm not an EE, but I know from past experience here in Silicon Valley that those separate ground rods at equipment could actually induce interference to sensitive equipment.

 

[Fulthrotl]

Hello,
I have a question, while I do not fully believe what I am seeking is a NEC reference, it may be something said in a CD from Mike Holt.
the reference is to a ground rod at each CNC Machine or to building ground. I BELIEVE it was said, " this ground rod was both not needed and determental to the functioning of the machine. Please refresh my memory.

Professionally,
Bob

really, you want everything to do with a CNC machine to be grounded to the same point.

a separate ground rod is a ground loop, and that isn't in your best interest.
the machines are a lot more stable than they were 25 years ago. floating grounds
could do things like make stepper motors step. when a half inch endmill goes
thru the part, the fixture, and a quarter inch of the machine bed, people get cranky.

 

[Kyell]

Thank you

Thank you

Thank you for your help, my problem arouse when the technician installing machine. Indicated the manufacture required a ground rod. I am still hesitant to place one. It did not fit what I knew. So requested information from manufacture help desk was useless. I am NOT installing one unless ordered to by the owner of the plant.

Thank you again,
Bob

 

[kwired]

Thank you for your help, my problem arouse when the technician installing machine. Indicated the manufacture required a ground rod. I am still hesitant to place one. It did not fit what I knew. So requested information from manufacture help desk was useless. I am NOT installing one unless ordered to by the owner of the plant.

Thank you again,
Bob

NEC has no problem with "supplemental" electrodes. If the manufacturer of your equipment wants one you may have little choice if you want them to honor any warranty. What you can not do is connect the machine to a ground and fail to run an equipment grounding conductor with the supply conductors.

 

[Saturn_Europa]

Thank you for your help, my problem arouse when the technician installing machine. Indicated the manufacture required a ground rod. I am still hesitant to place one. It did not fit what I knew. So requested information from manufacture help desk was useless. I am NOT installing one u

Thank you again,
Bob

https://youtu.be/qNZC782SzAQ


I just watched this video last night. Minute 10 Mike Holt explains why supplemental ground rods increase the likely hood if damage to CNC machines. He also points out studies that support this.