Microinverter has disconnected because AC voltage is outside the G98/G99 permitted window.
Common causes
High grid voltage (voltage rise from PV export)Low grid voltage (weak supply)Loose AC wiring at AC combiner or junction boxLong AC cable run with excessive voltage drop
What to check
STEP 1
Check voltage at the consumer unit and at a socket near the inverter. Log over time using Enlighten if voltage is intermittently high
STEP 2
If voltage is consistently high (above 253 V) due to export, check if the grid profile export limit is set correctly in Installer Toolkit
Escalate if
Voltage persistently out of range — notify DNO if above 253 V. If all MIs on one branch are affected, check branch wiring
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