1. Ask for the single-line diagram and protection schedule
You should be able to see how modules, strings, inverter, AC connection, isolation, earthing and surge-protection devices fit together.
2. Match the design to the installation
Model numbers, cable routes, isolators, protection devices and earthing conductors on site should correspond to the approved design or a documented as-built drawing.
3. Request test and commissioning records
Ask what electrical tests were performed, who performed them, the instruments or standards used, and the signed acceptance record.
4. Inspect visually from safe locations
Look for damaged enclosures, loose visible conduits, exposed conductors, water ingress or corrosion. Do not open inverter or DC combiner compartments unless qualified and authorised.
5. Escalate defects before normal operation
If protection is missing, visibly damaged or undocumented, obtain qualified inspection and written remediation instead of improvising a repair.