Blue Elephant is biting me

[jaypee89]

I should probably have used the correct term in my last post.
Any earth for protection purposes is what you'd technically call a Protective Earth (or PE for short). This is what the Earth is in your typical mains supply.
All the drives in your machine should have a PE, which is connected to Earth.

Floating neutral is a bit different. In the case of 3 phase, if you don't connect to a supply Neutral, the only way you'd have a floating neutral, is if you had something connected in Star (also referred to as Wye, but that's more a US convention).
Even on a machine that was fully isolated with/without a floating neutral, the structure would still be connected as a PE.

Now having realised exactly what drives you have, none of them are 3 phase, they all appear to be single phase 230VAC.
In the absence of any transformer, this would suggest that your machine should have a 3ph+Neutral supply (or possibly even just be single phase), and I'm also going to guess that none of your 3phase supplies have an RCD fitted, as the amount of current flowing through the earth is going to be well above RCD tripping current levels.

I'd suggest you trace the mains wiring to each drive, and figure out exactly how they're connected for power.

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