Thanks Irving

I'm working off of the circuit diagram in the pdf in my post, but that only shows the driver circuitry essentially and not the PSU specifically.

The PSU is this one Zapp Automation Ltd - Stepper motors & Stepper Motor Drivers - Servo motors and Servo Motor Drivers - Ballscrews & linear motion products. : PS806-5 Linear power supply [PS806-5] - £102.00

From what I can see the toroidal coil is bolted via that central bolt to a mainboard, which doesn't look like it has any copper substrate to it. The daughter board, which has the capacitors etc (rectifier?) is a standard PCB, which is wired to the coil(s) and that is also mounted on the main board by brass spacers. I currently have nylon spacers from the main board to the chassis, but could certainly replace those with brass also, if that's how its supposed to be earthed or maybe as you say it shouldn't have an earth connection at all (which I find a little difficult to believe, but I'm no expert).

I'll try and PM Gary @ Zapp and see if he can help (the data sheet for the PSU is next to useless, but that's normal for stuff like this I find).

Thanks for the sanity check in any case.


Chris

PS. I have removed the earth lead for now until I know how it should be wired.