Wire Gauge Information

American Wire Gauge (AWG) is a standardized wire gauge system used primarily in the North American electrical industry.

Key Formulas:

• Diameter: d = 0.127 * 92^((36-n)/39) mm
• Cross-sectional Area: A = π * (d/2)²
• Resistance: R = ρL/A (where ρ is resistivity, L is length, A is cross-sectional area)

Example Calculations:

Example 1: Copper wire, AWG #10, Voltage of 120 V, current of 10 A.

Using the formula for cross-sectional area:

For AWG #10:

Cross-sectional Area = π * (d/2)² = π * (2.588 mm / 2)² = 8.22 mm²

Using the resistance formula:

Resistance = ρ * L / A = 1.68 × 10^-6 Ω·m * 100 m / 8.22 mm² ≈ 0.0012 Ω/m

Example 2: Aluminum wire, SWG #8, Voltage of 240 V, current of 20 A.

For SWG #8:

Cross-sectional Area = π * (d/2)² = π * (4.115 mm / 2)² = 13.23 mm²

Resistance = ρ * L / A = 2.82 × 10^-6 Ω·m * 100 m / 13.23 mm² ≈ 0.0021 Ω/m

Why Wire Gauge Matters:

Choosing the right wire gauge ensures efficient and safe electrical performance. Using a gauge that is too small can result in excessive voltage drop and overheating, while using too large a gauge may be unnecessarily costly.

Wire Material:

The material of the wire (copper, aluminum, etc.) affects resistance, with copper generally offering lower resistance and higher efficiency compared to aluminum.