1. What is a Voltage Drop Calculator for Cables?

Definition: This calculator estimates the voltage drop in electrical cables based on material resistivity, cable length, current, and cross-sectional area.

Purpose: It helps electrical engineers and technicians ensure proper voltage levels in electrical installations 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 (Ω·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 the cable's resistance.

3. Importance of Voltage Drop Calculation

Details: Proper voltage drop estimation ensures electrical devices receive adequate voltage, prevents overheating, and maintains system efficiency.

4. Using the Calculator

Tips: Enter the conductor resistivity (default 1.68×10⁻⁸ Ω·m for copper), cable length in meters, current in amps, and cross-sectional area in m². All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why is voltage drop important?
A: Excessive voltage drop can cause equipment malfunction, reduced efficiency, and potential safety hazards.

Q2: What's a typical acceptable voltage drop?
A: Generally 3% for feeders and 5% for branch circuits, but consult local electrical codes.

Q3: What resistivity value should I use?
A: 1.68×10⁻⁸ Ω·m for copper, 2.82×10⁻⁸ Ω·m for aluminum at 20°C.

Q4: Does this work for three-phase systems?
A: For balanced three-phase, replace the 2 with √3 (about 1.732).

Q5: How do I convert AWG to m²?
A: Use our AWG to mm² converter or reference AWG size charts.