Aluminum Wire Resistance Calculator

Aluminum Resistance Equation:

\[ R = 2.65 \times 10^{-8} \frac{L}{A} \]

Resistance (R):

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1. What is Aluminum Wire Resistance?

The resistance of an aluminum wire depends on its length and cross-sectional area, with resistivity of aluminum being 2.65 × 10⁻⁸ Ω·m at 20°C. This property determines how much the wire opposes electric current flow.

2. How Does the Calculator Work?

The calculator uses the resistance equation:

\[ R = 2.65 \times 10^{-8} \frac{L}{A} \]

Where:

\( R \) — Resistance in ohms (Ω)
\( L \) — Length of wire in meters (m)
\( A \) — Cross-sectional area in square meters (m²)
\( 2.65 \times 10^{-8} \) — Resistivity of aluminum (Ω·m)

Explanation: The resistance increases with length and decreases with cross-sectional area according to this linear relationship.

3. Importance of Resistance Calculation

Details: Accurate resistance calculation is crucial for electrical system design, voltage drop calculations, and ensuring proper current carrying capacity in aluminum wiring applications.

4. Using the Calculator

Tips: Enter length in meters and cross-sectional area in square meters. For common wire gauges, you may need to convert from AWG to area. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Why is aluminum used for wiring despite higher resistance than copper?
A: Aluminum is lighter and less expensive than copper, making it suitable for applications where weight and cost are primary concerns.

Q2: How does temperature affect aluminum resistance?
A: Aluminum resistance increases with temperature by about 0.4% per °C rise (temperature coefficient of 0.00429/°C at 20°C).

Q3: What are typical applications of aluminum wiring?
A: Used in power transmission lines, large feeders in buildings, and applications where weight savings are important.

Q4: How does this compare to copper wire resistance?
A: Copper has lower resistivity (1.68 × 10⁻⁸ Ω·m), so copper wires of same dimensions would have about 60% of aluminum's resistance.

Q5: What safety considerations exist for aluminum wiring?
A: Proper terminations are critical as aluminum expands/contracts more than copper and can loosen connections over time, creating fire hazards.