A normal single-pole general-use switch controls a 120-volt branch circuit with one ungrounded conductor and one grounded conductor. Under the 2023 NEC 404.2(B) rule, which conductor should this switch interrupt?
- The ungrounded conductor
- BEither conductor, solely for wiring convenience
- COnly the grounded conductor
- DOnly the grounded conductor whenever GFCI protection is present
Where to look it up
https://docinfofiles.nfpa.org/files/AboutTheCodes/70/70_A2025_NEC_P09_FD_PIResponses.pdf
Why A is correct
This single-pole switch interrupts the ungrounded conductor. The grounded conductor cannot be independently opened under the general rule. The exception is broader than simultaneous disconnection alone: it also recognizes a device arranged so the grounded conductor cannot open until all ungrounded conductors are disconnected. Source: existing 2023 text of 404.2(B), reproduced struck through in NFPA Public Input 1543’s proposed Article 404 relocation, PDF page 304 (printed 182). https://docinfofiles.nfpa.org/files/AboutTheCodes/70/70_A2025_NEC_P09_FD_PIResponses.pdf