Looks good!
Having a single connection from the power supply - terminals to the power line G terminal is correct:
- It ensures the entire electronics layout is connected to frame / safety ground
- It eliminates the possibility of a “ground loop” current circulating through the supplies and the frame
In general, the wiring connected to frame ground (and, thus, the AC line’s yellow/green earth ground wire) would be the circuit “common” node, with all voltages measured relative to it.
The - terminal on the supply should be isolated from its own frame and G terminal, so that you could use the supply for either polarity:
- +24 V by connecting
-to common - -24 V by connecting
+to common
Bonus: you may find the OEM supply is underpowered for the loads it must carry. The supply in my laser is definitely overloaded (but coping) and a recent thread suggests that situation is common.
Which is why I added a 24 V laptop brick for the LEDs and solenoids and suchlike. The OEM supply is still overloaded, but at least I haven’t added to its misery. 