Blue Elephant is biting me

[jaypee89]

Just a wonder here..... what if I connected this floating earth malarky through a seperate wire to an earth spike, providing a proper earth while avoiding interference (which is why I believe it has been designed like this.) There is an earth ring terminal on the side of the cabinet with no wire coming from it. Could this have been meant for a spike? Hmmmm

[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:Attachment 32609

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.
Attachment 32610


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?

[jaypee89]

The supplies to the drivers all share the same nunbers, all off the same source. I don't fancy the previous owner to have been converting things from a 5 pin plug to 4, losing the neutral. With all respect to him, that's pretty advanced stuff that I just can't see happening.

I've noticed something really intersting this morning, the earth terminal with no wire is stickered with the earth symbol on the outside of the casing. More importantly, it's the heaviest gauge wire connection to the terminal strip of all the other PE's. It's screaming at me to earth it. I'd get you a photo, but my camera has grown legs atm cough (wife).

I'm in the process of acquiring an earth spike.

Any alarms on your end? I've done a little search on it, doesn't seem to be unheard of to have multiple earths on one machine

cheers

[m_c]

If the drive Neutral (or L1/L2) terminals are connected to the N11 terminal, then it is a neutral connector.

My guess is that whoever has wired it up previously, has bodged the wiring with 4 core, and just not connected the earth to the mains earth.