Question

What is the rated DC resistance of a 240 V single phase line, 560 feet long, wired with copper wire, USE AWG #2?

Answer 1

The rated DC resistance of the 240 V single-phase line is approximately 0.0884 ohms.

Step-by-step explanation:

Calculating the DC Resistance

Here's how to calculate the DC resistance of the 240 V single-phase line:

1. Gather information:

• Line voltage (V) = 240 V
• Line length (L) = 560 feet
• AWG size = #2

• Copper resistivity at 20°C (ρ) = 1.678 x 10⁻⁸ Ω⋅m

2. Convert units:

• Length L (feet) to meters (m): 560 ft * 0.3048 m/ft = 170.68 m

3. Calculate conductor cross-sectional area (A):

• Use an AWG wire table to find the cross-sectional area of AWG #2 copper wire: A = 3.31 mm² = 3.31 x 10⁻⁶ m²

4. Calculate DC resistance (R):

• Use the formula: R = ρ * L / A
• R = 1.678 x 10⁻⁸ Ω⋅m * 170.68 m / 3.31 x 10⁻⁶ m²
• R = 0.0884 Ω

Hence, the rated DC resistance is approximately 0.0884 ohms.