Solar Cable Sizing Guide for India (2026)
Undersized cables are one of the most common installation defects in Indian solar systems. A cable with >2% voltage drop causes permanent generation loss for the system's 25-year life. The IS 694 standard governs cable selection for solar installations in India.
Maximum Recommended Voltage Drop
- DC side (panels to inverter): Max 1.5% for high-performance systems, absolute max 3%
- AC side (inverter to distribution board): Max 2.5% per IS 694
- Total system losses from cables: Should not exceed 2%
Standard Cable Sizes for Indian Rooftop Solar
| System Size | DC Cable | AC Cable | Max Run |
|---|---|---|---|
| 1–3 kW | 4 mm² | 4 mm² | 20m |
| 3–5 kW | 6 mm² | 6 mm² | 30m |
| 5–10 kW | 10 mm² | 10 mm² | 40m |
Always use UV-resistant, double-insulated DC solar cables (TUV 2 PfG 1169/08.2007 certified) on the DC side. Standard house wiring (FR PVC) degrades rapidly in outdoor solar applications.