1. What is a Voltage Drop Cable Calculator?

Definition: This calculator estimates the voltage drop in electrical cables based on resistivity, length, current, and cross-sectional area.

Purpose: It helps electrical engineers and technicians ensure proper voltage levels in electrical installations.

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 formula calculates the voltage lost due to the resistance of the cable over its length.

3. Importance of Voltage Drop Calculation

Details: Proper voltage drop estimation ensures electrical devices receive adequate voltage for optimal operation and prevents excessive power loss.

4. Using the Calculator

Tips: Enter the resistivity (default 1.68×10⁻⁸ ohm-m for copper), cable length, current, and cross-sectional area. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why is there a factor of 2 in the formula?
A: The factor accounts for the round-trip path of current (both "go" and "return" conductors).

Q2: What's a typical resistivity value for copper?
A: Copper has ρ ≈ 1.68×10⁻⁸ ohm-m at 20°C. For aluminum, use 2.65×10⁻⁸ ohm-m.

Q3: What's an acceptable voltage drop?
A: Generally, voltage drop should be less than 3% for branch circuits and 5% for feeders.

Q4: How does temperature affect the calculation?
A: Higher temperatures increase resistivity. For precise calculations, use resistivity values at operating temperature.

Q5: How do I convert wire gauge to cross-sectional area?
A: Use AWG to mm² conversion tables or our Wire Gauge Calculator tool.