Skip to main content

⚡ Question Of The Week ⚡ (2026 NEC)

#QuestionOfTheWeek2026:

How many #12 AWG THHN conductors are permitted in a 4" × 4" metal box that is 1½ inches deep, with no devices, no internal clamps, and no equipment grounding conductors?

💬 Comment your answer AND explain why below.

⚠️ Disclaimer: The question may be simplified for educational purposes. Verify all requirements using the current NEC and any applicable local amendments.

⚡ Study Credit: TRADEHOG.NET ⚡

Good luck, code nerds. ⚡

⚡ Question Of The Week ⚡ (2026 NEC)

⚡ Question Of The Week ⚡ (2026 NEC)

Kenneth Hengst

Per T314.16A, (9) #12 conductors are allowed. A 4x4x1.5" box has 21cu.in. Per T314.16B, 21"/2.25" = 9.333... or 9 maximum conductors.

Joshua Audette

Kenneth Hengst 💯 great breakdown, Kenneth, thanks!

T314.16)A) indicates 9-#12 conductors are acceptable in a 4X4X1-1/2" square box

Joshua Audette

David Engelhart spot on, thanks David.