1. What is Volt Drop Calculation in Cables?

Definition: This calculator determines the voltage drop along an electrical cable based on its material properties and current load.

Purpose: It helps electricians and engineers ensure proper voltage levels at load points by accounting for cable resistance.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( VD \) — Voltage drop (volts)
• \( \rho \) — Resistivity of conductor material (ohm-m)
• \( L \) — Length of cable (meters)
• \( I \) — Current flowing through cable (amps)
• \( A \) — Cross-sectional area of conductor (m²)

Explanation: The factor of 2 accounts for the return path in single-phase systems. The formula calculates the voltage lost due to cable resistance.

3. Importance of Volt Drop Calculation

Details: Proper voltage drop calculation ensures electrical devices receive adequate voltage and prevents excessive power loss in cables.

4. Using the Calculator

Tips: Enter the conductor resistivity (default 1.68×10⁻⁸ ohm-m for copper), cable length, current, and cross-sectional area. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why is resistivity important?
A: Different materials (copper, aluminum) have different resistivities, affecting voltage drop.

Q2: What's a typical acceptable voltage drop?
A: Generally 3% for lighting circuits and 5% for other circuits from supply to load.

Q3: When would I change the factor of 2?
A: Use 1 for DC systems or three-phase systems where neutral current is zero.

Q4: How do I find cable cross-sectional area?
A: Check cable specifications or measure diameter and calculate area (πr²).

Q5: Does temperature affect the calculation?
A: Yes, resistivity changes with temperature. For precise calculations, adjust ρ for operating temperature.