Ivan
Two electrical questions, please

1) Run a ground wire at least equal to the phase wires. But at least #6 Bare
copper. Conduit does not cut it for ground unless you have some electrical
specifications for the conduit and the connectors. Which I have never seen or
heard of.

A plus for this will be a ground rod at the machine location drivern through a
hole drilled in the floor.

2) Run it all in conduit if possible or the code requires it. I don't think
the code allows for a 15 foot cord hanging down. Also a conduit has to be
supported evry so often. Not sure of the code for this. And above some HP
rating a safety switch is required for each machine. A 3 pole safety switch.
Securely mounted somewhere within sight of the machine when it is turned off
for whatever. Also if there is any use of 110 volts at the machine you will
need a neutral wire. And a plus for this would be to simply run the neutral to
each machine and provide for an outlef for lighting etc.

Additionally. If the machines are in a cluster it is possible to make just one
conduit run to the cluster.

If you do run conduit make it a size or two bigger to allow for growth or
change.

Hope this helps
Bob AZ