Message from Daniel Lichter:

I have been asked to define our end of the industry.

We manufacture skidded equipment, tanks vessels, etc., which hold a liquid for some type of processing. Be it heating, mixing with another liquid, distributing to another vessel, or whatever.

Along with these vessels are air actuated valves with limit switches; we use 24 vdc analog devices to indicate flow, pressure, and temperature.

Most of our controls are 24 vdc. The pump motors are usually 480 vac.

My question is, do we fall under NEC Article 670 (Industrial Machinery)?

Which in turn leads us to NFPA 79. If we do, can we disregard NEC Article 300 as per 300.1(b)?

It is getting to be quite a pain in the head if you know what I mean. I can’t find anything in the NEC, or other NFPA publications that clearly gives a definition of the difference between what would be house (building) wiring, and equipment (machine) wiring.

A little nudge in the right direction would be helpful.

Thank you all very much.
Daniel Lichter


Joe Tedesco, NEC Consultant