Does LPSU ground need grounded to chassis?

[jarrodl]

Does the black ground wire coming from the laser power supply need grounded to the frame of the unit?
Will it hurt anything if it is?

[Techgraphix]

Earthing can be tricky:
Best to check if the Signal-GND is internaly connected to the case (with a multimeter in Ohms). I hope not..
The Mains-GND is best to be connected to your central-earthing -(star)point (CEP)
Signal-GND better NOT.
You can use shielded cable. Connect ONLY one side to the CEP, leave the other end open.. Do this for all shielding.
All wires leading to the CEP must only be connected to ONE thing so NO link-through...

Think that all currents flowing through those cabels may not influence other cables so all those wires come together at one point, the Central Earthing (Star)point (or CEP)

Also mind that connecting a cable to GND on both sides will give you a loop.. strange things can be caused bij these groundloops.. so try to avoid them at any time..

Kees