Q. Am I required to install the secondary circuit conductors of a low-voltage lighting system (less than 30V) in a raceway or cable like power conductors?

A. If the low-voltage conductors will be concealed or extended through a building wall, they must be installed using any Chapter 3 wiring method, such as within a raceway, cable, or enclosure, just like power conductors [411.4(A)(1)]. In addition, if the low-voltage wiring is supplied by a Class 2 power source, it can be installed using the requirements of 725.52. This means you can use 150V cable [725.82(G)], boxes are not required, and the Class 2 conductors cannot be mixed with power conductors in raceways or enclosures unless separated by a barrier [725.55].