1. What is a Low Voltage Drop Calculator?

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 at the load end of circuits.

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 formula calculates the voltage loss in both the supply and return conductors (hence the factor of 2).

3. Importance of Voltage Drop Calculation

Details: Proper voltage drop calculation ensures electrical equipment receives adequate voltage for proper operation and prevents energy waste.

4. Using the Calculator

Tips: Enter the conductor resistivity (default 1.68×10⁻⁸ ohm-m for copper), cable length, current, and conductor 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 branch circuits and 5% for feeders, but check local codes.

Q3: Why multiply by 2 in the formula?
A: It accounts for both the supply and return paths in the circuit.

Q4: How do I find conductor resistivity?
A: Use standard values (1.68×10⁻⁸ ohm-m for copper, 2.65×10⁻⁸ for aluminum).

Q5: Does this include temperature effects?
A: No, for precise calculations, adjust resistivity for operating temperature.