1. What is a Voltage Drop Calculator mm²?

Definition: This calculator estimates the voltage drop in an electrical circuit based on conductor resistivity, length, current, and cross-sectional area in mm².

Purpose: It helps electricians and engineers ensure proper voltage levels in electrical installations by calculating potential voltage loss.

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)
• \( A_{mm²} \) — Cross-sectional area of conductor (mm²)

Explanation: The formula calculates voltage drop for a round-trip circuit (hence the factor of 2), accounting for conductor properties and load.

3. Importance of Voltage Drop Calculation

Details: Proper voltage drop estimation ensures electrical equipment receives adequate voltage, prevents performance issues, and complies with electrical codes.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: What's the typical resistivity for copper?
A: Copper at 20°C has ρ ≈ 1.68×10⁻⁸ Ω·m. For aluminum, use ≈ 2.82×10⁻⁸ Ω·m.

Q2: Why is there a factor of 2 in the formula?
A: It accounts for both the "hot" and "neutral" (or positive and negative) conductors in the circuit.

Q3: What's an acceptable voltage drop?
A: Typically 3% for branch circuits and 5% for feeders, but check local electrical codes.

Q4: How does temperature affect the calculation?
A: Higher temperatures increase resistivity. For precise calculations, adjust ρ for operating temperature.

Q5: Can I use this for DC circuits?
A: Yes, the formula works for both AC and DC circuits when using appropriate values.