1. What is a Voltage Drop Calculator?

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

Purpose: It helps electricians and engineers ensure proper voltage levels throughout 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 conductor (meters)
• \( I \) — Current flowing through conductor (amps)
• \( A \) — Cross-sectional area of conductor (m²)

Explanation: The formula calculates the voltage lost due to the resistance of the conductor 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 0.000000000000172 ohm-m for copper), conductor length in meters, current in amps, and cross-sectional area in m². 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 out and return conductors).

Q2: What's the typical resistivity for copper?
A: Copper has resistivity of about 1.72×10⁻⁸ ohm-m at 20°C (default value in calculator).

Q3: How does conductor material affect voltage drop?
A: Different materials have different resistivities (e.g., aluminum has higher resistivity than copper).

Q4: What's an acceptable voltage drop?
A: Typically less than 3% for branch circuits and 5% for feeders, but check local codes.

Q5: Does temperature affect the calculation?
A: Yes, resistivity changes with temperature. For precise calculations, adjust resistivity for operating temperature.