Re: Electrical Ground
If there is presently Galvanic isolation between the service GND and the P.S. Common then normally it can be earth grounded.
One test is to measure between the P.S. common and earth, you might see some voltage there, now place a low value (~100ohm) resistor between the two and see if the voltage collapses, if so it should be safe to take it to earth GND.
As a matter of course I try to earth connect all commons if possible back to the star point GND.
Most suppliers of boards use isolation quoting noise separation reasons, but noise can be transmitted through a system inductively or capacitively with no physical connection.
If you have a tower or desk P.C. it most likely is going to have the PS connected to earth.
Al.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.