1. What is an SWA Cable Size Calculator?

Definition: This calculator determines the required cross-sectional area of Steel Wire Armored (SWA) cable based on current and ampacity rating.

Purpose: It helps electricians and engineers select the appropriate cable size for electrical installations to ensure safe current carrying capacity.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( A \) — Cross-sectional area of cable (m²)
• \( I \) — Current (amps)
• \( \text{ampacity\_rating} \) — Current carrying capacity per unit area (A/m²)

Explanation: The current is divided by the ampacity rating to determine the minimum required cross-sectional area for safe operation.

3. Importance of Proper Cable Sizing

Details: Correct cable sizing prevents overheating, ensures efficient power transmission, and meets electrical safety standards.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: What is ampacity rating?
A: Ampacity rating is the current carrying capacity per unit cross-sectional area of the cable, typically measured in A/m².

Q2: What's a typical ampacity rating for SWA cable?
A: Standard SWA cables typically have ampacity ratings between 800-1200 A/m² depending on insulation material and installation conditions.

Q3: When would I need to adjust the ampacity rating?
A: Adjust for different cable types, higher ambient temperatures, or when cables are installed in groups or enclosed spaces.

Q4: How do I find the actual current?
A: Calculate based on load requirements or measure using a clamp meter for existing installations.

Q5: Does this include safety factors?
A: No, consider adding 25-30% to the calculated size for safety margins and future expansion.