1. What is the Wire Size Equation?

The wire size equation calculates the minimum cross-sectional area of a conductor needed to safely carry a given electrical current, based on the current density.

2. How Does the Calculator Work?

The calculator uses the wire size equation:

Where:

• \( A \) — Cross-sectional area of wire (mm²)
• \( I \) — Current (Amperes)
• \( J \) — Current density (A/mm²)

Explanation: The equation ensures the wire can handle the current without excessive heating, based on the material's current carrying capacity.

3. Importance of Proper Wire Sizing

Details: Correct wire sizing is crucial for electrical safety, preventing overheating, voltage drop, and potential fire hazards in electrical installations.

4. Using the Calculator

Tips: Enter current in amperes and current density in A/mm². Typical current densities range from 3-6 A/mm² for copper wires in building wiring.

5. Frequently Asked Questions (FAQ)

Q1: What current density should I use?
A: For general building wiring, 4 A/mm² is common. Higher densities may be used for short runs or special applications.

Q2: How does wire material affect sizing?
A: Copper has higher conductivity than aluminum, allowing smaller sizes for the same current. Adjust current density accordingly.

Q3: What about voltage drop?
A: This calculator considers heating only. For long runs, voltage drop calculations may require larger wire sizes.

Q4: Are there standard wire sizes?
A: Yes, wires come in standard sizes (e.g., 1.5, 2.5, 4, 6, 10 mm²). Always round up to the nearest available size.

Q5: What factors increase current density requirements?
A: High ambient temperatures, bundled wires, or enclosed spaces may require lower current densities for safety.