Length Using Load Current (Single-Phase Two-Wire OS) Calculator

Formula Used:

\[ Length of Overhead AC Wire = \frac{Line Losses \times Area of Overhead AC Wire}{2 \times (Current Overhead AC)^2 \times Resistivity} \] \[ L = \frac{P_{loss} \times A}{2 \times I^2 \times \rho} \]

Line Losses:

Watt

Area of Overhead AC Wire:

m²

Current Overhead AC:

Ampere

Resistivity:

Ω·m

Length of Overhead AC Wire:

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is Length Using Load Current Calculation?

The Length Using Load Current calculation determines the maximum length of an overhead AC wire based on line losses, wire area, current, and material resistivity. This is essential for designing efficient electrical distribution systems.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ L = \frac{P_{loss} \times A}{2 \times I^2 \times \rho} \]

Where:

\( L \) — Length of Overhead AC Wire (meters)
\( P_{loss} \) — Line Losses (Watt)
\( A \) — Area of Overhead AC Wire (m²)
\( I \) — Current Overhead AC (Ampere)
\( \rho \) — Resistivity (Ω·m)

Explanation: This formula calculates the maximum wire length that can be used while maintaining acceptable power loss levels in a single-phase two-wire overhead system.

3. Importance of Length Calculation

Details: Accurate length calculation is crucial for optimizing electrical distribution systems, minimizing energy losses, ensuring voltage stability, and reducing operational costs in overhead power transmission.

4. Using the Calculator

Tips: Enter line losses in watts, wire area in square meters, current in amperes, and resistivity in ohm-meters. All values must be positive numbers greater than zero.

5. Frequently Asked Questions (FAQ)

Q1: Why is the factor 2 used in the denominator?
A: The factor 2 accounts for the fact that in a single-phase two-wire system, the current flows through both the outgoing and return wires, effectively doubling the resistance.

Q2: What is typical resistivity for copper wires?
A: Copper has a resistivity of approximately 1.68 × 10⁻⁸ Ω·m at 20°C, though this varies with temperature and purity.

Q3: How does wire area affect the calculation?
A: Larger wire areas reduce resistance, allowing for longer wire lengths with the same power loss, or the same length with less power loss.

Q4: What are acceptable line loss percentages?
A: Typically, distribution systems aim for line losses between 3-5% of the total power transmitted, though this varies by application and regulations.

Q5: Does temperature affect this calculation?
A: Yes, resistivity changes with temperature. For accurate calculations, use resistivity values at the expected operating temperature.