Resistivity using Area of X-Section (3 Phase 4 Wire US) Calculator

Formula Used:

\[ \rho = \frac{A \times P_{loss} \times (V_m)^2 \times (\cos(\Phi))^2}{4 \times L \times (P)^2} \]

Area of Underground AC Wire (A):

m²

Line Losses (P_loss):

Maximum Voltage Underground AC (V_m):

Phase Difference (Φ):

rad

Length of Underground AC Wire (L):

Power Transmitted (P):

Resistivity (ρ):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is the Resistivity Calculation Formula?

The formula calculates the resistivity (ρ) of a material used in underground AC wire systems. Resistivity is a fundamental property that quantifies how strongly a material opposes the flow of electric current.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ \rho = \frac{A \times P_{loss} \times (V_m)^2 \times (\cos(\Phi))^2}{4 \times L \times (P)^2} \]

Where:

\( \rho \) — Resistivity (Ω·m)
\( A \) — Area of Underground AC Wire (m²)
\( P_{loss} \) — Line Losses (W)
\( V_m \) — Maximum Voltage Underground AC (V)
\( \Phi \) — Phase Difference (rad)
\( L \) — Length of Underground AC Wire (m)
\( P \) — Power Transmitted (W)

Explanation: This formula accounts for various electrical parameters to determine the intrinsic resistivity of the wire material.

3. Importance of Resistivity Calculation

Details: Accurate resistivity calculation is crucial for designing efficient electrical systems, minimizing power losses, selecting appropriate materials, and ensuring system safety and reliability.

4. Using the Calculator

Tips: Enter all values in the specified units. Ensure all inputs are positive values. The phase difference should be in radians (0 to π/2 for typical AC systems).

5. Frequently Asked Questions (FAQ)

Q1: Why is resistivity important in electrical systems?
A: Resistivity determines how much a material resists current flow, affecting power loss, heating, and efficiency of the electrical system.

Q2: What are typical resistivity values for common conductors?
A: Copper has resistivity of about 1.68×10⁻⁸ Ω·m, aluminum is about 2.82×10⁻⁸ Ω·m, and silver is about 1.59×10⁻⁸ Ω·m at 20°C.

Q3: How does temperature affect resistivity?
A: For most conductors, resistivity increases with temperature. The relationship is approximately linear for many materials over typical operating ranges.

Q4: What factors can cause errors in resistivity calculation?
A: Measurement inaccuracies, temperature variations, material impurities, and non-uniform cross-sectional areas can affect the accuracy of resistivity calculations.

Q5: How is this formula different from basic resistivity formulas?
A: This specialized formula accounts for AC system parameters including phase difference and maximum voltage, making it specifically useful for underground AC power transmission systems.