1. What is Voltage Drop Calculation?

Definition: This calculator determines the voltage drop in an electrical circuit according to Australian standards (AS/NZS 3008).

Purpose: It helps electricians and engineers ensure proper voltage levels throughout electrical installations.

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 conductor (amps)
• \( A \) — Cross-sectional area of conductor (m²)

Explanation: The formula calculates the voltage loss that occurs due to the resistance of the conductor over its length.

3. Importance of Voltage Drop Calculation

Details: Proper voltage drop calculation ensures electrical equipment receives adequate voltage and complies with Australian standards (maximum 5% drop for most installations).

4. Using the Calculator

Tips: Enter the conductor resistivity (default 1.72×10⁻⁸ Ω·m for copper), cable length in meters, current in amps, and conductor cross-sectional area in m².

5. Frequently Asked Questions (FAQ)

Q1: Why is the formula multiplied by 2?
A: The factor of 2 accounts for the return path in single-phase circuits (both active and neutral conductors).

Q2: What's the typical resistivity for copper?
A: Copper at 20°C has ρ ≈ 1.72×10⁻⁸ Ω·m. For aluminum, use ρ ≈ 2.82×10⁻⁸ Ω·m.

Q3: How do I convert mm² to m² for conductor area?
A: Divide mm² by 1,000,000 (e.g., 2.5 mm² = 2.5×10⁻⁶ m²).

Q4: What's the maximum allowable voltage drop?
A: AS/NZS 3000 specifies max 5% at the farthest point of the circuit (3% for lighting circuits).

Q5: Does this account for temperature effects?
A: No, for precise calculations at different temperatures, adjust resistivity accordingly.