⚡Question Of The Week⚡
Question:
What’s the conductor-equivalent count
Box: 4" square, 1-1/2" deep metal box (21.0 in³), internal NM clamps.
Cables entering:
(2) 12/2 NM-B (black, white, bare)
(1) 12/3 NM-B (black, red, white, bare)
Device: (1) single-pole switch on a yoke.
Grounds: all bare grounds tied with a wirenut + 12 AWG pigtail to the metal box.
All splices/terminations in this box.
The switch has 2 insulated conductors terminated on it (no feed-through conductors under the same screws).
Please Comment & Discuss Below.
Note: As always with my questions, there may be errors; feel free to call these out, as it teaches me to create better questions!
Have a great, productive week, everybody! always learning!
Credit: TRADEHOG.NET
But whats MORE important is what you present here is actually an NEC violation. Let's see who can explain why.
Paul Abernathy I'll take a crack at it!
Total Conductor Count:
(NEC 314.16(B))
Insulated conductors: 7
Grounds: +1
Internal clamps: +1
Device yoke: +2
Total = 11 conductor equivalents
Volume Calculation:
Each 12 AWG conductor = 2.25 in³
11 × 2.25 = 24.75 in³ required
Box Size:
The box in question is:
21.0 in³
Since 24.75 in³ is required, this box is too small.
I believe this results in a box fill violation!! We would have to size this up in the real world.
Josh A. Perfect
Paul Abernathy it was trivia last night! helped bring everything together! 💯