This wiring method is the multioutlet assembly. Article 380 doesn't have a section 2, so it does not define the multioutlet assembly. For that definition, we must turn to Article 100. It's a raceway designed to hold conductors and receptacles. This is kind of obvious from its name. The assembly may be assembled in the field or at the factory. It may be surface-mounted, flush, or free-standing .
- The NEC doesn't provide a list of "Uses Permitted" for this wiring method [380.10]. It simply says it's permitted in dry locations.
- There are six. You can't use it where concealed (with exception noted), subject to physical damage (the standard prohibition), where the voltage between conductors is 300V or more (unless it's a metal assembly at least 1.02mm thick), in hoistways, or in any hazardous location unless specifically permitted elsewhere in the NEC [380.12].
- Typically, this question is answered in section 30 of an Article. But Article 380 doesn't have a section 30. Basically, you have to use appropriate hardware. For a qualified electrician, figuring out what's appropriate isn't particularly challenging.
- This is kind of a trick question, as you don't use couplings and connectors with these. But beware of the daisy chain problem. You don't power one multioutlet assembly from an outlet in another. You can, however, use them as pullboxes [380.23(B)].