Blue Elephant is biting me

[m_c]

Below is a photo showing 0 continuity between the earths and actual earth. The RCDs are not connected to the machine's earths, would explain why it's not tripping:

You are correct with the drivers, they're single phase. I've traced back there supply and it's directly from a phase, through a 20A fuse and EMI filter. This phase also supplies the cabinet fans and a transformer for the 24v motion control board. The neutral from the drives is connected to the supply earth (though the emi and fuse also). Pencil pointing at the single phase suppy.



Thanks for your input M_C, much appreciated

That N11 tag on the wiring, I'd guess that should be Neutral.
What do the other tags on the input power wires say?