Grounding scheme

[IQChallenged]

Would this be a correct star-rounding scheme (the one on the right)? Must all grounds meet at the star (as shown), or just the drivers? Are there any grounds that must not go there? What kind of problems would or might occur with non-star grounding? Thanks

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[Al_The_Man]

If using this method, setting up a central point where all commons are connected to, ensures that at least one point in any of the points that may come in contact with ground, either intentionally or accidentally, at least here are exactly at the same potential.
It is virtually impossible to only ground at one point of every metalic part of the machine.
For example, when you bring a ground wire back from a spindle motor to the star point, the motor frame itself could also have a path through the frame of the machine to say a air supply pipe etc.
By bonding that motor and any other metal part of the machine to this star point, is attempting to achieve a uniform bonding of all the machine to earth ground potential.
Sometimes called uni-potential bonding.
When you don't set up a common ground plate, different points can have different potentials to ground due to spurious ground paths currents or differing resistance between ground points.
Al.

[IQChallenged]

Originally Posted by Al_The_Man If using this method, setting up a central point where all commons are connected to, ensures that at least one point in any of the points that may come in contact with ground, either intentionally or accidentally, at least here are exactly at the same potential. It is virtually impossible to only ground at one point of every metalic part of the machine. For example, when you bring a ground wire back from a spindle motor to the star point, the motor frame itself could also have a path through the frame of the machine to say a air supply pipe etc. By bonding that motor and any other metal part of the machine to this star point, is attempting to achieve a uniform bonding of all the machine to earth ground potential. Sometimes called uni-potential bonding. When you don't set up a common ground plate, different points can have different potentials to ground due to spurious ground paths currents or differing resistance between ground points. Al.

Yeah, that's what I was thinking :-)