1. What is a Volt Drop Calculator (Australia)?

Definition: This calculator determines the voltage drop in electrical cables according to Australian standards.

Purpose: It helps electricians and engineers ensure proper voltage levels at load points by accounting for cable resistance.

2. How Does the Calculator Work?

The calculator uses the Australian standard 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 cable resistance.

3. Importance of Voltage Drop Calculation

Details: Proper voltage drop calculation ensures electrical equipment receives adequate voltage for safe and efficient operation, complying with AS/NZS 3000 wiring rules.

4. Using the Calculator

Tips: Enter the conductor resistivity (default 1.72×10⁻⁸ Ω·m for copper), cable length, current, and conductor cross-sectional area. 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 the maximum allowed voltage drop in Australia?
A: AS/NZS 3000 generally recommends no more than 5% voltage drop from supply to load.

Q3: What resistivity value should I use for aluminum cables?
A: Use approximately 2.82×10⁻⁸ Ω·m for aluminum conductors.

Q4: Does this calculator work for three-phase systems?
A: This formula is for single-phase. For three-phase, use \( VD = \sqrt{3} \times \rho \times L \times I / A \).

Q5: How do I convert mm² to m² for cable area?
A: Divide mm² by 1,000,000 (e.g., 2.5mm² = 2.5×10⁻⁶ m²).