Just a thought, but regardless of whether it affects the machine or not, ANY fixed or portable electrical equipment with exposed metal surfaces should be securely grounded using a conductor capable of carrying at least the full current of the protective device fitted to the supply.

Now, if that affects the machine, there is more work to do because it shouldn't.

China has very lax attitudes to grounding - both my 3kw water cooled spindle motors were not grounded to the 4th connector pin, my chinese laser cutter was not grounded either.

Just a thought, but regardless of whether it affects the machine or not, ANY fixed or portable electrical equipment with exposed metal surfaces should be securely grounded using a conductor capable of carrying at least the full current of the protective device fitted to the supply.

Now, if that affects the machine, there is more work to do because it shouldn't.

China has very lax attitudes to grounding - both my 3kw water cooled spindle motors were not grounded to the 4th connector pin, my chinese laser cutter was not grounded either.

Thanks Dave, I agree.

Ian wrote (long ago):
""and you connect all 0 volt lines to a star point which is earthed,"

I suspect this has been misunderstood by a few people. What it means is that you should connect all the 0v lines from power supplies (and other things if needed) to a single point (eg a brass bolt on a large aluminium plate supporting the drivers and interfaces), AND that plate should be earthed with a separate wire back to the mains input.

That's my understanding of the SAA Wiring Regs in Australia anyhow.

Cheers
Roger

Thanks Roger