Neon lighting is ubiquitous outdoors. It’s bright and colorful, plus the signs can be made into many different shapes. This makes it perfect for outdoor signs, because they can be made to really stand out.
But neon lighting operates at high voltage so it has its own special hazards. Thus, Article 600 devotes nearly all of Part II to it. There are only two Parts to Article 600.
The only non-neon item in Part II is 600.33, which pertains to the secondary wiring of LED sign illumination systems. This seems an odd place for something about LED, which operates at around 3V to 5V while neon typically operates at 2kV or higher.
Neon is also called “skeleton tubing” and the reason why becomes clear if you look carefully at a few of these systems.
If you’re installing neon lighting, don’t just flip to Part II and start from there. All of the other requirements of Article 600 also apply to neon lighting. Part II simply provides additional requirements.
If your secondary-circuit wiring is under 1kV, you can use any Chapter 3 wiring method suitable for the conditions. But the conductors can’t be smaller than 18 AWG [600.31(A) and (B)]. Make sure you always use bushings when passing wires through any metal opening [600.31]. The number of conductors in a raceway can’t exceed the applicable value in Table 1 of Chapter 9.