1. What is Voltage Drop?

Voltage drop is the reduction in voltage in an electrical circuit between the source and load. It occurs due to the resistance of conductors and can affect equipment performance.

2. How Does the Calculator Work?

The calculator uses the voltage drop equation:

Where:

• \( VD \) — Voltage drop (volts)
• \( L \) — Length of cable (meters)
• \( I \) — Current (amps)
• \( \rho \) — Resistivity of conductor material (ohm-m)
• \( A \) — Cross-sectional area of conductor (m²)

Explanation: The equation calculates the voltage loss along a cable based on its length, current, material properties, and size.

3. Importance of Voltage Drop Calculation

Details: Proper voltage drop calculation ensures electrical devices receive adequate voltage to operate correctly and prevents excessive power loss in wiring.

4. Using the Calculator

Tips: Enter cable length in meters, current in amps, resistivity in ohm-m (default is copper at 1.68×10⁻⁸ ohm-m), and cross-sectional area in m².

5. Frequently Asked Questions (FAQ)

Q1: What is an acceptable voltage drop?
A: Typically 3% for branch circuits and 5% for feeder circuits, but check local electrical codes.

Q2: Why is there a factor of 2 in the equation?
A: The factor accounts for the round-trip path of current (both out and return conductors).

Q3: What's the resistivity of common materials?
A: Copper: 1.68×10⁻⁸ ohm-m, Aluminum: 2.65×10⁻⁸ ohm-m, Silver: 1.59×10⁻⁸ ohm-m.

Q4: How does cable size affect voltage drop?
A: Larger cables (greater cross-sectional area) reduce voltage drop for the same current.

Q5: When is voltage drop most critical?
A: In long cable runs, high current applications, and sensitive electronic equipment.