Microinverter Systems¶
Microinverters convert DC to AC at the panel level — one inverter per panel. This eliminates the string architecture entirely and provides per-panel MPPT, monitoring, and rapid shutdown compliance without additional hardware.
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Enphase Systems
IQ series microinverters, Envoy gateway, Enlighten monitoring, and field diagnostics.
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APsystems
APsystems dual-module microinverters, ECU gateway, and monitoring platform.
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Gateway Systems
Communication gateways for each platform — the bridge between microinverters and the monitoring cloud.
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Troubleshooting
Common microinverter field failures and diagnostic approaches.
Microinverter vs. String — Key Differences¶
| Feature | String Inverter | Microinverter |
|---|---|---|
| MPPT | Per string | Per panel |
| Shade tolerance | Low | High |
| Single point of failure | Inverter failure = system down | One microinverter failure = one panel offline |
| Monitoring granularity | String level | Panel level |
| Maintenance complexity | Single unit | Many units (one per panel) |
| AC wiring | Single run from inverter | AC branch circuits across the array |
| Rapid shutdown | Separate equipment needed | Built-in (AC is safe without grid) |
Key Concept: AC Branch Circuits¶
In a microinverter system, the wiring between the panels and the roof is AC, not DC. This has safety implications:
- Without grid power, microinverters stop producing — no hazardous DC voltage on the roof
- But AC wiring still exists and can be live if the grid is on
- For maintenance: isolate at the AC disconnect breaker
Common Microinverter Failure Patterns¶
- Individual unit failure (one panel goes offline) — most common
- Gateway failure (all panels lose monitoring) — appears as full outage in portal but system may be producing
- Ground fault — rare but possible
- AC wiring connection failure at the trunk cable