Garmaine Staff asked 1 year ago

First, some context: About AFCI protection in Dwelling Units, NEC 2017:

210.12(A) All 120-volt, single-phase, 15- and 20-ampere branch circuits supplying outlets or devices installed […] shall be protected by […]

(4) A listed outlet branch-circuit type arc-fault circuit interrupter installed at the first outlet on the branch circuit in combination with a listed branch-circuit overcurrent protective device where all of the following conditions are met:

  • a. The branch-circuit wiring shall be continuous from the branch-circuit overcurrent device to the outlet branch-circuit arc-fault circuit interrupter.
  • b. The maximum length of the branch-circuit wiring from the branch-circuit overcurrent device to the first outlet shall not exceed 15.2 m (50 ft) for a 14 AWG conductor or 21.3 m (70 ft) for a 12 AWG conductor.
  • c. The first outlet box in the branch circuit shall be marked to indicate that it is the first outlet of the circuit.
  • d. The combination of the branch-circuit overcurrent device and outlet branch-circuit AFCI shall be identified as meeting the requirements for a system combination-type AFCI and shall be listed as such.

So how is "continuous wiring" defined in context of the 2017 NEC code? It is not listed in its Definitions chapter. Is it the same as electrical continuity? Mechanical continuity? Not-interrupted-by-switches-that-are-potentially-open-continuity? or something else? In a different context, Mike Holt states [1]:

Conductors in raceways must be continuous between all points of the system. This means you can't place splices in the raceway[…]

Is this correct? If so / if not: Can you provide a reference?

[1] https://www.mikeholt.com/mojonewsarchive/NEC-HTML/HTML/Article-300-Wiring-Methods~20031029.htm