Panels and inverters get the attention, but most problems on rooftops come from the structure, the wiring and the earthing. MNRE’s technical specifications for PM Surya Ghar set clear rules for each.
Structure
- Hot-dip galvanised steel or aluminium, designed for your area’s wind speed with a safety factor of 1.5
- Stainless steel fasteners
- At least 600 mm clearance above the roof for cooling and cleaning
Cables
- Single-core copper solar cable on the DC side (IS 17293)
- Copper AC cable sized so that losses stay below 2%
- All cables in conduit or a covered tray, clamped properly
Earthing and lightning protection
- Separate earth pits for the DC side, the AC side and the lightning arrester
- Earth resistance below 5 ohms
- Lightning arrester on its own support, not on the panel structure
- Surge protection devices in the DC and AC boxes
What to ask any installer
- Which brand and model of panel, inverter and cable will be used?
- How many earth pits, and what cable sizes?
- Who maintains the system, and for how long?
Every Lumisun quote answers these in writing.
