Quick Hits

Episode 3: Conductor Sizing & The 20-Foot Rule (750.66 – 750.100(A))

SLIDE 1 (HOOK / COVER) ⚡ NEC Quick Hit: Grounding Conductor Sizing & Length (Part 3) ⚡ 

What size wire do you need for limited-energy grounding electrode conductors? How long can that run be in a residential home? Let's check out Section 750.100! 👇

SLIDE 2 (CONDUCTOR SIZING & MATERIALS) Wire Gauge Requirements:

• Minimum Size: Bonding and grounding electrode conductors for cables/protectors shall not be smaller than 14 AWG copper (and not smaller than 10 AWG copper for antenna masts/power systems).

• Corrosion Resistance: Must be copper or other corrosion-resistant conductive material (avoid raw aluminum within 18 inches of the earth).

SLIDE 3 (THE 20-FOOT DWELLING LENGTH RULE) Keeping Runs Short:

• Straight Line Mandate: Bonding conductors must be run in as straight a line as practicable.

• The 20-Foot Cap: In one- and two-family dwellings, the bonding conductor length shall not exceed 6.0 m (20 ft). (Note: If 20 ft cannot be achieved, a separate driven ground rod must be added and bonded to the power system).

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

Limiting your low-voltage grounding conductor length to 20 feet in residential builds minimizes impedance, ensuring that lightning energy and power surges safely clamp to earth without arcing across internal building pipes!

💬 Save this post for your next low-voltage bonding layout! 🔗

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