Quick Hits

Episode 1: Scope, Ampacities & Minimum Sizing (402.1 – 402.6)

SLIDE 1 (HOOK / COVER)

⚡ NEC Quick Hit: Fixture Wires (Part 1 - Article 402) ⚡

Internal luminaire wiring, ampacity tables, and minimum conductor sizes—welcome to Article 402! How does the National Electrical Code regulate fixture wires? Let's break down the fundamentals! 👇

SLIDE 2 (SCOPE & GENERAL REQUIREMENTS)

What Article 402 Covers:

• The Fixture Wire Scope: Covers general requirements and construction specifications for fixture wires.

• Design Purpose: Fixture wires are designed for installation inside luminaires and similar equipment, or for connecting luminaires to branch-circuit conductors.

• Strict Prohibitions: Fixture wires shall not be used as branch-circuit conductors unless explicitly permitted elsewhere in the Code.

SLIDE 3 (AMPACITIES & SIZING)

Current Ratings and Conductor Limits:

• Table 402.5 Ampacities: Copper fixture wire ampacities are specified by size: 18 AWG = 6A, 16 AWG = 8A, 14 AWG = 17A, 12 AWG = 23A, and 10 AWG = 28A.

• Minimum Sizes: Fixture wires shall not be smaller than 18 AWG solid or stranded copper (or 16 AWG solid copper-clad aluminum).

• Temperature Limits: No conductor shall be operated under conditions where its temperature exceeds the maximum rating specified for its insulation type.

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

Overload protection for 18 and 16 AWG fixture wires isn't provided by standard 15A or 20A branch-circuit OCPDs—protection is achieved by limiting luminaire lamp, ballast, or driver loads to Table 402.5 ampacities!

💬 Save this post for your next luminaire wiring project!

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