Your guidance will come from Article 90, the introduction to the NEC.
Look at what the NEC is intended to address- and, just as important, what it does not address. You will note that vehicles, ships, aircraft, light rail, rolling stock, and a great many other things are not addressed by the NEC.
Why, you ask, might this be? Well, here are a few reasons:
First off, any 'rule book' is based on a set of basic principles. Different folks developing something, independent of each other, will often take opposing approaches. Either approach might be excellent, but the two methods are not compatable. For example, look at the gulf between "Windows" and "Apple."
Many things - ships, trains, and mines come to mind - already had their set of principles, their 'rule book,' long before the NEC came about.
Likewise, the basic assumptions might be irrellevant to another application. For example, a ground rod is a bit impractical for the Space Station. You might even create a dangerous situation - one example is when folks apply the NEC to a mine, and wind up blowing things up or electrocuting people.
That's why a designer has to have a very clear understanding of electricity, lest bad things happen. One absolutely must understand the difference between 'grounding' and 'bonding.'
That said, we are seeing far more circumstances that challenge the traditional role of the NEC, and it's not an area that's settled at all. There's more to electricity than volts and amps - and we're only beginning to learn.
To answer your basic question, though ... If the application involved people and the usual appliances at the usual voltages, MOST NEC principles will be reasonable. Otherwise, all bets are off.
