1. What is a DC Cable Voltage Drop Calculator?

Definition: This calculator estimates the voltage drop in a DC electrical cable based on conductor material, length, current, and cross-sectional area.

Purpose: It helps electrical engineers and technicians ensure proper voltage levels at the load end of DC power systems.

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

Explanation: The factor of 2 accounts for the round-trip path (positive and negative conductors) in DC circuits.

3. Importance of Voltage Drop Calculation

Details: Proper voltage drop calculation ensures electrical equipment receives adequate voltage for proper operation and prevents excessive power loss in cables.

4. Using the Calculator

Tips: Enter the conductor resistivity (1.68×10⁻⁸ Ω·m for copper), cable length in meters, current in amps, and conductor area in m². All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why is resistivity important?
A: Different materials have different resistivities (copper = 1.68×10⁻⁸ Ω·m, aluminum = 2.65×10⁻⁸ Ω·m) which affect voltage drop.

Q2: What's an acceptable voltage drop?
A: Typically 3% or less for power circuits, 5% or less for lighting circuits, but check local electrical codes.

Q3: How do I convert AWG to m²?
A: Use our AWG to mm² converter or refer to wire gauge tables (e.g., 10 AWG ≈ 5.26 mm² = 5.26×10⁻⁶ m²).

Q4: Does this account for temperature?
A: No, this uses resistivity at 20°C. For higher temperatures, multiply result by (1 + αΔT) where α is temperature coefficient.

Q5: When would I use single conductor vs two conductors?
A: For single conductor (one-way) circuits, remove the factor of 2 from the formula.