Short answerCheck the structure (hot-dip galvanised and anchored), earthing (three separate pits), cabling (solar-grade copper in conduit with matched MC4 connectors), protection (SPDs, fuses, lightning arrester), inverter placement (shaded and ventilated), and paperwork (DCR certificate, warranties, invoice) before you sign off.
Structure
- Hot-dip galvanised steel, not painted mild steel
- Anchored with chemical anchors or proper civil footings; no loose ballast
- Tilt about 15–18°, facing south, clear of tank and parapet shadows
- Walkway space to clean every panel safely
Electrical
- Solar DC cable (4 or 6 sq mm copper) in UV-resistant conduit
- MC4 connectors of one brand, crimped with the right tool
- DC distribution box with fuses and surge protection
- AC distribution box with MCB and SPD
- Three earth pits with test readings recorded
- Lightning arrester above the highest panel
Inverter
- Mounted in shade with airflow; never in direct afternoon sun
- Wi-Fi monitoring set up on your phone before the crew leaves
Paperwork and handover
- Invoice naming panel and inverter brand, model and wattage
- DCR certificate and panel serial numbers
- Panel, inverter and workmanship warranty cards
- Earth resistance test values
- Cleaning and safety demo
Red flags: a quote without brand names, no mention of earthing, “subsidy guaranteed” promises from an unregistered installer, or pressure to pay in full before feasibility approval.
Frequently asked questions
How many earth pits does a rooftop system need?
Good practice is three: one for the DC side (panels and structure), one for the AC side (inverter output), and one for the lightning arrester.
Should panels face south?
In Telangana, south-facing at a tilt of about 15–18° gives the best yearly output. East-west layouts work when the roof shape demands it, with a small loss.