[ \textMin. Cross Section (mm²) = \frac2 \times \rho \times I \times LV_d ]
Let’s break it down. Electricity flowing through a cable generates heat. The smaller the cable, the more resistance and heat it produces. The goal is to choose a cable large enough to carry the required current without exceeding its temperature rating.
Now calculate cable size for , not 5A. Quick Reference: Common Cable Sizes & Current Ratings (Copper, 30°C) Use this as a starting point only—always verify with local codes.
| Condition | Derating Factor | | :--- | :--- | | Ambient 30-40°C (normal) | 1.00 | | Ambient 40-50°C (hot attic) | 0.87 | | 3-6 cables bundled | 0.80 | | 7-9 cables bundled | 0.70 |
If your 5A fridge runs through a hot attic (0.87) and is bundled with 4 other cables (0.80): ( 5 / (0.87 \times 0.80) = 5 / 0.696 = 7.2A )
[ \textMin. Cross Section (mm²) = \frac2 \times \rho \times I \times LV_d ]
Let’s break it down. Electricity flowing through a cable generates heat. The smaller the cable, the more resistance and heat it produces. The goal is to choose a cable large enough to carry the required current without exceeding its temperature rating. calculate cable size
Now calculate cable size for , not 5A. Quick Reference: Common Cable Sizes & Current Ratings (Copper, 30°C) Use this as a starting point only—always verify with local codes. [ \textMin
| Condition | Derating Factor | | :--- | :--- | | Ambient 30-40°C (normal) | 1.00 | | Ambient 40-50°C (hot attic) | 0.87 | | 3-6 cables bundled | 0.80 | | 7-9 cables bundled | 0.70 | The smaller the cable, the more resistance and
If your 5A fridge runs through a hot attic (0.87) and is bundled with 4 other cables (0.80): ( 5 / (0.87 \times 0.80) = 5 / 0.696 = 7.2A )