1. What is the Wire Size Calculation?

The wire size calculation determines the appropriate cross-sectional area of a wire needed to carry a specific current over a distance while maintaining acceptable voltage drop. This is crucial for electrical safety and efficiency.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• Current — The current in amperes (A)
• Distance — The length of the wire in meters (m)
• Resistivity — The material's resistivity (Ω·m)
• Voltage Drop — Maximum acceptable voltage drop (V)
• Voltage — System voltage (V)

Explanation: The formula accounts for the resistance in the wire over distance and ensures the voltage drop stays within acceptable limits.

3. Importance of Proper Wire Sizing

Details: Proper wire sizing prevents excessive voltage drop, reduces energy loss, minimizes heat generation, and ensures electrical safety by preventing overheating.

4. Using the Calculator

Tips: Enter all required values. Typical copper resistivity is 1.68×10⁻⁸ Ω·m. Standard voltage drop limits are 3% for branch circuits and 5% for feeders.

5. Frequently Asked Questions (FAQ)

Q1: What is the standard resistivity for copper?
A: 1.68×10⁻⁸ Ω·m at 20°C for pure copper. Polycab wires may have slightly different values.

Q2: How does temperature affect the calculation?
A: Higher temperatures increase resistivity. For precise calculations at different temperatures, adjust the resistivity value.

Q3: What's a typical acceptable voltage drop?
A: Generally 3% for branch circuits and 5% for feeders, but consult local electrical codes.

Q4: Does this work for both AC and DC systems?
A: Yes, but for AC systems consider skin effect and power factor for more accurate calculations.

Q5: How do I select the nearest standard wire size?
A: Always round up to the next available standard wire size (e.g., 2.5mm², 4mm², 6mm²).