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EPISODE 5 — Wire-Bending Space at Terminals: When Conductors Enter Opposite Their Terminal (312.9(B))
EPISODE 5 — Wire-Bending Space at Terminals: When Conductors Enter Opposite Their Terminal (312.9(B))
Slide 1 — Hook "Today: what changes when a conductor has to travel ACROSS the box to reach its terminal, instead of landing directly across from where it enters."
Slide 2 — The two scenarios
312.9(B)(1): if conductors DON'T enter/leave through the wall OPPOSITE their terminal, Table 312.9(A) (from last episode) applies as normal.
312.9(B)(2): if conductors DO enter/leave through the wall opposite their terminal, a DIFFERENT table applies — Table 312.9(B)(2) — because that longer diagonal travel path needs more clearance to bend properly without stress.
Table 312.9(B)(2) numbers run noticeably larger than Table 312.9(A) at the same conductor size — e.g., a single 500 kcmil conductor needs 14" under (B)(2) vs. just 6" under Table 312.9(A) for a similar size band.
Slide 3 — The exceptions
Exception No. 1: if the distance between the wall and terminal already meets Table 312.9(A), a conductor CAN enter/leave opposite its terminal — as long as it does so where the gutter joins an ADJACENT gutter that itself meets Table 312.9(B)(2).
Exception No. 2: for meter-socket-only enclosures, conductors up to 350 kcmil can enter/leave opposite their terminal under Table 312.9(A) spacing instead, IF the terminal is a lay-in type or removable lug with integral mounting tang, AND it's either angled within 45° of directly facing the wall, or directly facing it with an offset no greater than 50% of the Table 312.9(A) bending space.
Table 312.9(B)(2) also allows REDUCED bending space for removable/lay-in single-conductor terminals — specific inch reductions noted per size band.
Slide 4 — Quiz + CTA Q: "Why does Table 312.9(B)(2) generally require MORE bending space than Table 312.9(A) for the same conductor size?" A) It's an arbitrary code requirement B) Conductors entering opposite their terminal need a longer bend path, requiring more clearance C) Table 312.9(B)(2) is only for aluminum conductors D) There's no actual difference between the two tables
✅ Answer: B — the longer diagonal bend path when a conductor enters opposite its terminal needs more room to avoid stressing the conductor/insulation.
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⚠️ Educational NoticeQuick Hits are educational explanations based on my understanding of the NEC. Always verify requirements in the current adopted NEC, applicable local amendments, manufacturer instructions, and with the AHJ.
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