Greg, trust me on this ... dairies get LOTS of inspections
BTW, the USDA inspector trumps everyone else.
The OP is 'crossing a line' here. Once you take a bunch of equipment, cobble it together, and mount it on a skid ... the NEC no longer applies, as you have constructed an 'appliance.' The same principle applies to process equipment and assembly lines.
That's one of the real problems with the new NEC section about control panels .... there's absolutely no way for any NRTL to review what the controls are telling the machinery to do - all they can do is measure clearances.
The NEC almost starts off by stating that methods need to be suitable for the environment .... and those 'environmental' factors can easily include sanitation requirements, etc.
We can use the NEC, product standards, etc., for guidance .... but, when you're making an appliance, it comes down to your design requirements and professional judgment.
This is also the reason that the NEC recognizes the need for the AHJ to be able to disregard parts of the code. Industrial situations can very easily become "special" cases.
