Derating Factor For Cables Here

[ 0.85 \times 0.70 \times 0.75 = 0.446 ]

| | Reference Temp. | Derating at 50°C | Derating at 60°C | |----------------------|--------------------|----------------------|----------------------| | PVC | 30°C | 0.71 | 0.58 | | XLPE / EPR | 40°C | 0.89 | 0.77 | derating factor for cables

| | Arrangement | Derating factor | |----------------------|--------------------------------|---------------------| | 1 | Single circuit, free air | 1.00 | | 2–3 | Touching, in air | 0.80–0.85 | | 4–5 | Touching, in air | 0.70–0.75 | | 6–8 | Touching, in air | 0.60–0.65 | | >9 | Touching, in air | 0.50–0.55 | 9 | Touching

[ 200 , A \times 0.446 = 89.2 , A ]

| | Thermal Resistivity | Derating factor | |------------------------|-------------------------|---------------------| | Damp clay/loam | 1.0 – 1.5 | 1.05 – 1.10 | | Standard (IEC assumed) | 2.5 | 1.00 | | Dry sand/gravel | 3.0 – 4.0 | 0.70 – 0.85 | 4. Depth of Burial (for buried cables) Deeper burial reduces heat dissipation (soil is cooler but more insulating). A \times 0.446 = 89.2