1. What is a Voltage Drop Calculator by Unbound Solar?

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

Purpose: It helps solar installers and electrical engineers ensure proper voltage levels in DC circuits, particularly important in solar power systems.

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 conductor (meters)
• \( I \) — Current flowing through conductor (amps)
• \( A \) — Cross-sectional area of conductor (m²)

Explanation: The factor of 2 accounts for the round-trip path of current in a circuit. Voltage drop increases with longer wires, higher current, or smaller wire sizes.

3. Importance of Voltage Drop Calculation

Details: Proper voltage drop estimation ensures efficient power transmission, prevents excessive power loss, and maintains equipment performance in solar installations.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: Why is voltage drop important in solar systems?
A: Excessive voltage drop reduces system efficiency and can prevent proper charging of batteries or operation of inverters.

Q2: What's a typical acceptable voltage drop?
A: For DC circuits, generally keep voltage drop below 3% of system voltage for optimal performance.

Q3: How do I find the cross-sectional area of my wire?
A: Check wire specifications or use: Area = π × (radius)² for round conductors.

Q4: What resistivity value should I use for aluminum wire?
A: Use approximately 2.65×10⁻⁸ ohm-m for aluminum conductors.

Q5: Does this calculator work for AC circuits?
A: This formula is for DC circuits. AC circuits require additional factors like power factor and frequency.