1. What is Resistance Using Line Losses?

Resistance Underground AC is defined as the property of the wire or line that opposes the flow of current through it. This calculator determines the resistance based on line losses and current in a 1-Phase 2-Wire Mid-Point Earthed system.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( R \) — Resistance Underground AC (Ohm)
• \( P_{loss} \) — Line Losses (Watt)
• \( I \) — Current Underground AC (Ampere)

Explanation: The formula calculates the resistance by dividing the power losses by twice the square of the current flowing through the system.

3. Importance of Resistance Calculation

Details: Accurate resistance calculation is crucial for determining power efficiency, voltage drop analysis, and proper system design in underground AC electrical systems.

4. Using the Calculator

Tips: Enter line losses in watts and current in amperes. All values must be valid positive numbers (line losses > 0, current > 0).

5. Frequently Asked Questions (FAQ)

Q1: Why is the factor of 2 used in the denominator?
A: The factor of 2 accounts for the two-wire system in a 1-phase configuration where losses occur in both conductors.

Q2: What are typical resistance values for underground cables?
A: Resistance values vary based on cable material, size, and length. Copper cables typically have lower resistance than aluminum cables of the same size.

Q3: How does temperature affect resistance calculations?
A: Resistance increases with temperature. The calculated value represents resistance at the operating temperature when measurements were taken.

Q4: Can this formula be used for DC systems?
A: Yes, the same formula applies to DC systems since it's based on fundamental electrical principles (P = I²R).

Q5: What are common causes of high line losses?
A: High resistance due to long cable runs, small conductor size, poor connections, or elevated operating temperatures can cause increased line losses.