Centroid Community CNC Support Forum

I am aware of the issues you pointed out. Obviously, you may continue to do as you see fit.

I will continue to believe that switching the ground is not best practice. As you said, ground is a safety circuit.

There's been a lot of interesting discussion on this thread. The important point is that every schematic that I've looked at that is published by Centroidcnc looks perfectly safe to use. They are excellent schematics, that, if understood and followed, will get you up and running in a minimum of time.

I try to keep in mind that those schematics show the internal connections - connections that are made inside an enclosure. If there is any doubt about making the connections between the enclosure and the power source, i.e., wall-socket or hard-wired branch circuit, then you should consult a licensed electrician.

Question:
Building a Plasma CNC machine:
Two power supplies are used for the Plasma system, one for the Acorn board and THC RX and a separate +24VC for the Plasma THC TX board.
Should the common on each power supply be connected to chassis at each power supply?

I also have two separate power supplies (+24VDC & 5VDC) for my existing Acorn powered CNC machine, should each one's common be connected to chassis at the power supply terminals?

I tie all commons together, including chassis ground. It might help to visualize current as water. COMMON would be the ocean into which all current flows. A power supply whose GND/COMMON is NOT connected to the GND/COMMON of other power supplies might be represented as Lake Tahoe, at 6,225 feet above sea level. Think of the potential force (power) of water running from Lake Tahoe to the ocean if that water found a path. It could do a massive amount of damage wherever it flowed. Just like water, electricity follows the path of least resistance. It it can find a path to a lower voltage, it will. It that path of least resistance is through the Acorn then goodbye Acorn. If GND/COMMON/CHASSIS are all tied together, there is no difference between the reference points of all power supplies and GND.

Thanks, will do that on my machine and do it for the Plasma machine.