1. What is a Voltage Drop Calculator?

Definition: This calculator estimates voltage drop in electrical circuits according to AS/NZS 3008 standards for both AC and DC systems.

Purpose: 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 fundamental voltage drop 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)

AC Adjustment: For AC circuits, the result is multiplied by 1.1 to account for skin effect and reactance.

3. Importance of Voltage Drop Calculation

Details: Proper voltage drop calculation ensures electrical equipment receives adequate voltage for proper operation and complies with AS/NZS 3008 standards.

4. Using the Calculator

Tips:

• Select current type (AC or DC)
• Enter conductor resistivity (default 1.72×10⁻⁸ ohm-m for copper)
• Input cable length, current, and conductor 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 typical resistivity for copper?
A: 1.72×10⁻⁸ ohm-m at 20°C for pure copper. Adjust for temperature and material purity.

Q3: Why does AC have a higher voltage drop?
A: AC systems experience additional losses due to skin effect and reactance.

Q4: What are AS/NZS 3008 limits for voltage drop?
A: Typically 5% of nominal voltage for general circuits, 3% for lighting circuits.

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