1. What is a Distance Voltage Drop Calculator?

Definition: This calculator determines the maximum distance a cable can run before experiencing a specified voltage drop, based on conductor properties and current.

Purpose: It helps electricians and engineers design electrical systems to maintain proper voltage levels over long cable runs.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

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

Explanation: The formula calculates how far current can travel through a conductor before the voltage drops below an acceptable level.

3. Importance of Voltage Drop Calculation

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

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: Why is the distance multiplied by 2 in the formula?
A: The factor of 2 accounts for the round-trip path of current (both the "hot" and "neutral" wires in AC circuits).

Q2: What's a typical acceptable voltage drop?
A: For most applications, a 3% voltage drop is acceptable for branch circuits and 5% for feeder circuits.

Q3: What resistivity values should I use?
A: Common values are 1.68×10⁻⁸ ohm-m for copper and 2.65×10⁻⁸ ohm-m for aluminum at 20°C.

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

Q5: Can I use this for both AC and DC circuits?
A: Yes, but for AC circuits at higher frequencies, additional factors like skin effect may need consideration.