1. What is a Service Wire Size Calculator?

Definition: This calculator determines the minimum cross-sectional area of electrical wire needed based on current and ampacity.

Purpose: It helps electricians and engineers select properly sized wires to prevent overheating and ensure safe electrical installations.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( A \) — Wire cross-sectional area (m²)
• \( I \) — Current (amps)
• ampacity — Current carrying capacity (A/m²)

Explanation: The current is divided by the ampacity rating to determine the minimum wire size needed to safely carry the current.

3. Importance of Proper Wire Sizing

Details: Correct wire sizing prevents overheating, voltage drop, and potential fire hazards while ensuring efficient power delivery.

4. Using the Calculator

Tips: Enter the current in amps and the ampacity rating (default 1000 A/m² for copper). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is ampacity?
A: Ampacity is the maximum current a conductor can carry without exceeding its temperature rating.

Q2: How do I find the ampacity for my wire?
A: Consult NEC tables or manufacturer specifications based on wire material, insulation type, and ambient temperature.

Q3: What's the difference between AWG and mm² measurements?
A: AWG (American Wire Gauge) is a logarithmic scale, while mm² directly measures cross-sectional area. This calculator uses m².

Q4: Should I round up the calculated wire size?
A: Yes, always round up to the nearest standard wire size for safety.

Q5: Does this account for voltage drop?
A: No, this calculates minimum size based on ampacity. For long runs, calculate voltage drop separately.