IMHO,
Art. 670 seems to apply to the internal wiring of self-contained machines, or systems of machines such as might be found in metal shops, printing shops, package handling, etc, where a feeder is run to the machine.
If you are building skid units that essentially mimic an installation that would otherwise be performed at a plant, it seems to me that it would be considered premises wiring, and all the applicable NEC rules would apply.
In other words,
If you feed a motor from a panel that is mounted and wired at your shop and then delivered, that should not exempt you from following the same rules that would apply if it the motor was installed from a panel at the plant.
BTW Daniel,
Are these chemical processing vessels with process control instrumentation?
Who do you work for and what brands of instrumentation do you use?
[This message has been edited by Redsy (edited 10-23-2002).]
