Installation, Setup, and Configuration
What you must understand
Installation questions test sequence and restraint. Start with the site: structural capacity, roof covering, attachment method, wind and snow load, and code-required setbacks. Then the mechanical work - rail spacing, clamp zones marked by the module manufacturer, torque values, flashing and sealing of every penetration, and wire management that keeps conductors off the roof surface.
Electrical work covers conductor sizing and ampacity after temperature and conduit-fill derating, voltage drop, equipment grounding, rapid shutdown, and disconnects. Then configuration: string sizing against the inverter's MPPT window, one module type and orientation per MPPT input, communications (Wi-Fi, Ethernet, RS-485, power-line carrier), and monitoring enrollment.
Traps that appear in questions
- Sizing only for the best case, ignoring cold-morning Voc and hot-roof Vmp.
- Mixing module models or orientations on one MPPT input.
- Forgetting expansion fittings on long straight conduit runs.
- Reversing DC polarity at the inverter - always verify before energizing.
- Trusting memory for torque; the manufacturer's label governs.
Worked example
Inverter maximum DC input is 600 V. The coldest-condition module Voc is 44.2 V. Maximum modules per string = 600 ÷ 44.2 = 13.6, so round down to 13. Then confirm that 13 modules at hot-cell Vmp still clears the MPPT minimum. Rounding up here would over-voltage the inverter on a cold morning.