1. What is the Aluminium Cable Current Capacity Calculation?

The aluminium cable current capacity calculation determines the maximum current that an aluminium cable can safely carry based on its copper equivalent capacity, adjusted for aluminium's higher resistivity.

2. How Does the Calculator Work?

The calculator uses the aluminium current capacity formula:

Where:

• \( I \) — Aluminium current capacity (A)
• Copper equivalent — Current capacity of equivalent copper cable (A)
• 0.775 — Adjustment factor for aluminium resistivity

Explanation: The 0.775 factor accounts for aluminium's higher electrical resistivity compared to copper, which results in lower current carrying capacity for the same cable size.

3. Importance of Current Capacity Calculation

Details: Accurate current capacity calculation is crucial for proper cable sizing, preventing overheating, ensuring electrical safety, and maintaining system efficiency in electrical installations.

4. Using the Calculator

Tips: Enter the current capacity of the equivalent copper cable in amperes. The value must be greater than zero for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: Why is aluminium's current capacity lower than copper's?
A: Aluminium has higher electrical resistivity (approximately 2.82×10⁻⁸ Ω·m) compared to copper (approximately 1.68×10⁻⁸ Ω·m), resulting in lower current carrying capacity for the same cross-sectional area.

Q2: When should I use aluminium cables instead of copper?
A: Aluminium cables are often used in high-voltage transmission lines and large-scale installations where weight and cost savings outweigh the lower conductivity, as aluminium is lighter and less expensive than copper.

Q3: Are there other factors affecting current capacity?
A: Yes, factors such as ambient temperature, installation method, cable bundling, and insulation type also significantly affect the current carrying capacity of both aluminium and copper cables.

Q4: How accurate is the 0.775 conversion factor?
A: The 0.775 factor is a general approximation based on resistivity ratios. For precise calculations, consult specific cable manufacturer specifications and relevant electrical standards.

Q5: Can this calculator be used for DC and AC systems?
A: The basic resistivity relationship applies to both DC and AC systems, but AC systems require additional considerations for skin effect and proximity effect, especially at higher frequencies.