1. What is a Wire Length Voltage Drop Calculator?

Definition: This calculator determines the maximum wire length that can be used before experiencing a specified voltage drop, based on the wire's properties and current.

Purpose: It helps electricians and engineers design electrical systems with proper voltage levels at the load end.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( L \) — Maximum wire length (meters)
• \( VD \) — Acceptable voltage drop (volts)
• \( A \) — Cross-sectional area of wire (m²)
• \( \rho \) — Resistivity of wire material (ohm-m)
• \( I \) — Current flowing through wire (amps)

Explanation: The formula calculates how far current can travel through a wire before the voltage drops below acceptable levels.

3. Importance of Voltage Drop Calculation

Details: Proper voltage drop calculation ensures electrical devices receive adequate voltage to operate correctly and efficiently.

4. Using the Calculator

Tips:

• Enter the maximum acceptable voltage drop (typically 3% of supply voltage)
• Provide the wire's cross-sectional area (convert AWG to m² if needed)
• Use resistivity of copper (1.68×10⁻⁸ Ω·m) or aluminum (2.65×10⁻⁸ Ω·m)
• Enter the expected current load

5. Frequently Asked Questions (FAQ)

Q1: Why is there a factor of 2 in the formula?
A: The factor of 2 accounts for the round-trip path of current (to the load and back).

Q2: What's a typical acceptable voltage drop?
A: For most applications, 3% of supply voltage is acceptable (e.g., 3.6V for 120V systems).

Q3: How do I convert AWG to cross-sectional area?
A: Use our AWG to mm² converter or refer to standard wire gauge tables.

Q4: What resistivity value should I use for copper wire?
A: Pure copper at 20°C has ρ = 1.68×10⁻⁸ Ω·m (default value in calculator).

Q5: Does temperature affect the calculation?
A: Yes, resistivity increases with temperature. For high-temp applications, use adjusted ρ values.