Quick Hits

Episode 3: Grounding, Bonding & Wiring Space Rules (409.60 – 409.104)

SLIDE 1 (HOOK / COVER) ⚡ NEC Quick Hit: Bonding & Wiring Space (Part 3) ⚡ 

Multisection equipment bonding, surge protection, 40% raceway fill limits, and wire-bending requirements—let's review Sections 409.60 through 409.104! 👇

SLIDE 2 (GROUNDING & MULTISECTION BONDING)Safeguarding Enclosures:

• Equipment Grounding: An EGC sized per Table 250.122 must connect to an equipment grounding bus or terminal point in single-section panels.

• Multisection Bonding: Multisection industrial control panels must be bonded together using equipment bonding jumpers sized per Section 250.102(D).

• Surge Protection: Safety circuits for personnel protection subject to damage from surges require surge protection within or immediately adjacent to the panel.

SLIDE 3 (WIRING SPACE & TAPS)Enclosure Fill Limits:

• Not a General Gutter: Control panel enclosures cannot be used as raceways or junction boxes for feeding through or tapping off to other equipment unless conductors fill less than 40% of the cross-sectional wiring space area.

• Splice Limits: Conductors, splices, and taps cannot fill the wiring space at any cross section to more than 75%.

SLIDE 4 (WRAP-UP) 💡 Apprentice Pro-Tip: 

Don't treat an industrial control panel as an auxiliary gutter or junction box for unrelated circuits—keeping fill levels below 40% prevents severe overheating and code violations!

💬 Save this post for your next control panel layout! 🔗 

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