A large number of 'inverter faults' we attend are actually installation problems that could have been avoided. These seven mistakes account for most repeat failures — and most are cheap to fix if caught early.
1. Installing the inverter in direct sun
Inverters derate or shut down when hot. Direct afternoon sun on the unit in North India pushes internal temperature well above design — the inverter quietly loses output exactly when generation should peak.
2. Enclosing or boxing the inverter
Wall niches, glass cabinets and tight cupboards trap heat. An inverter needs clear ventilation clearance on all sides as specified by the manufacturer.
3. Undersized AC/DC cables
Long or thin AC cables raise voltage at the inverter terminals — causing over-voltage trips at midday. Undersized DC cables cause losses and heating at terminations.
4. Weak or missing earthing & SPD
Poor earthing causes isolation faults and RCD tripping; missing SPDs let surges destroy input boards during lightning or grid events.
5. Bad cable entry / no drip protection
Open cable glands and unprotected joints let rainwater and humidity into the DC box — the classic cause of monsoon isolation faults.
6. Loose terminations
Thermal cycling loosens terminals over months. Loose DC/AC connections heat up, discolour and eventually burn — visible in thermal scans long before failure.
7. No commissioning verification
Skipping string-wise Voc/Isc recording, insulation test, grid parameter check and protection settings means faults are found later, under load, expensively.
Getting it right the first time
- Shaded, ventilated, weather-protected location
- Correct cable sizing for length and current
- Tested earthing with recorded resistance and SPDs installed
- Torqued terminations and proper cable entries
- Full commissioning report with string and protection data
Frequently asked questions
Can I move an inverter that was installed in the sun?
Yes, and it is often worth it. Relocating to a shaded, ventilated position reduces derating and heat-related failures significantly.
Need a solar inverter repaired?
Share your inverter brand, model and error code — our technicians will guide you and share an estimate before any repair starts.