1. What is a Medium Voltage Cable Voltage Drop Calculator?

Definition: This calculator estimates the voltage drop in medium voltage cables based on cable properties and current flow.

Purpose: It helps electrical engineers and technicians ensure proper voltage levels are maintained in medium voltage distribution systems.

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 drop considering the round-trip path of current (hence the factor of 2), conductor material properties, and cable dimensions.

3. Importance of Voltage Drop Calculation

Details: Proper voltage drop estimation ensures equipment receives adequate voltage, prevents power quality issues, and maintains system efficiency.

4. Using the Calculator

Tips: Enter the conductor resistivity (default 1.72×10⁻⁸ ohm-m for copper), cable length, current, and cross-sectional area. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why is resistivity important?
A: Resistivity determines how strongly a material opposes current flow. Copper (1.72×10⁻⁸ Ω·m) and aluminum (2.82×10⁻⁸ Ω·m) are common conductor materials.

Q2: What's considered an acceptable voltage drop?
A: Typically 3-5% of system voltage for medium voltage distribution, but consult local regulations.

Q3: Why multiply by 2 in the formula?
A: The factor accounts for the round-trip path of current (both "go" and "return" paths).

Q4: How do I find the cross-sectional area?
A: Check cable specifications or measure diameter and calculate area (A = πr² for round conductors).

Q5: Does this account for temperature effects?
A: No, for precise calculations, adjust resistivity for operating temperature or use temperature-corrected formulas.