1. What is Electrical Cable Size Calculation?

Electrical cable size calculation determines the appropriate cross-sectional area of a cable needed to safely carry electrical current while maintaining acceptable voltage drop levels. Proper sizing ensures electrical safety and system efficiency.

2. How Does the Calculator Work?

The calculator uses the cable size formula:

Where:

• \( Current \) — Electrical current in amperes (amps)
• \( Length \) — Cable length in meters (m)
• \( Resistivity \) — Material resistivity in ohm-meters (ohm-m)
• \( Voltage\ drop \) — Maximum allowable voltage drop in volts

Explanation: The formula calculates the minimum cable cross-sectional area required to maintain the specified voltage drop for the given current and cable length.

3. Importance of Proper Cable Sizing

Details: Proper cable sizing is crucial for electrical safety, preventing overheating, ensuring efficient power transmission, and maintaining equipment performance by minimizing voltage drops.

4. Using the Calculator

Tips: Enter current in amps, length in meters, resistivity in ohm-m, and maximum allowable voltage drop in volts. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is typical copper resistivity?
A: Copper has a resistivity of approximately 1.68 × 10⁻⁸ ohm-m at 20°C.

Q2: What is typical aluminum resistivity?
A: Aluminum has a resistivity of approximately 2.82 × 10⁻⁸ ohm-m at 20°C.

Q3: What is an acceptable voltage drop?
A: Typically 3-5% of the supply voltage for power circuits, but specific requirements may vary by application and local electrical codes.

Q4: Why is cable size important?
A: Undersized cables can overheat, cause voltage drops, and create fire hazards. Oversized cables are more expensive and difficult to install.

Q5: Does temperature affect the calculation?
A: Yes, resistivity changes with temperature. The calculator uses standard room temperature values unless specified otherwise.