1. What is DC Voltage Drop Calculation?

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

Purpose: It helps electricians and engineers ensure proper voltage levels in DC power systems by accounting for conductor resistance.

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 factor of 2 accounts for the return path in DC circuits. Voltage drop increases with cable length and current, but decreases with larger conductor area.

3. Importance of Voltage Drop Calculation

Details: Proper voltage drop calculation ensures electrical devices receive adequate voltage for operation and prevents excessive power loss in cables.

4. Using the Calculator

Tips:

• Default resistivity (1.72×10⁻⁸ ohm-m) is for copper at 20°C
• For aluminum, use 2.82×10⁻⁸ ohm-m
• Multiply mm² by 1×10⁻⁶ to get m²

5. Frequently Asked Questions (FAQ)

Q1: What's the maximum allowable voltage drop in Australia?
A: AS/NZS 3000 generally recommends ≤3% for lighting and ≤5% for other circuits from origin to load.

Q2: Why does temperature affect voltage drop?
A: Conductor resistance increases with temperature, so voltage drop increases in warmer environments.

Q3: How do I convert AWG to m²?
A: Use standard AWG to mm² conversion tables, then multiply by 1×10⁻⁶ to get m².

Q4: Does this account for AC effects?
A: No, this is for pure DC circuits. AC calculations require additional factors for frequency and power factor.

Q5: What if I have multiple conductors in parallel?
A: Divide the current by number of parallel paths and calculate for one conductor.