Quick Hits

⚡ NEC Quick Hit: Conductor Stranding (Table 10) ⚡ 

Ever wonder what the actual difference is between Class B and Class C stranding? Chapter 9, Table 10 spells out the exact number of strands for copper and aluminum building wire. Let's break it down! 👇

SLIDE 2 (SMALL & BUILDING WIRE SIZES: #14 to #2) Standard Building Wire Stranding (#14 to #2 AWG):

• Copper Class B: 7 strands (Standard building wire)

• Copper Class C: 19 strands (Higher flexibility)

• Aluminum Class B: 7 strands (Note: Aluminum #14 is not available!)

• Small Control / Fixture Wires:

  • #18 AWG: 16 strands

  • #16 AWG: 26 strands

SLIDE 3 (FEEDER & HEAVY SIZES: 1/0 to 500 kcmil) Feeder Stranding Breakdown (Class B vs Class C):

• 1 to 4/0 AWG:

  • Copper Class B: 19 | Class C: 37 | Aluminum: 19

• 250 to 500 kcmil:

  • Copper Class B: 37 | Class C: 61 | Aluminum: 37

• 600 to 1000 kcmil:

  • Copper Class B: 61 | Class C: 91 | Aluminum: 61

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

Class C stranding uses more individual strands than Class B, making the cable much more flexible and easier to maneuver through tight bends. Just remember: always verify your lugs and wire connectors are rated for your specific stranding class!

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