Growatt
Error 306
Grid Frequency Out of Range
Grid frequency has gone outside the G98/G99 permitted range (47--52 Hz) and the inverter disconnected for compliance.
Common causes
Grid frequency event on the distribution networkGenerator or UPS on site causing frequency instabilityTest equipment interfering with supply
What to check
STEP 1
Check if any generator or UPS is running on site. Grid frequency events are typically brief -- inverter should auto-reconnect within minutes
STEP 2
Log event times. If recurring at specific times, report to DNO as a supply quality complaint
Escalate if
Occurs repeatedly (more than once daily) with no obvious local cause -- log and report to DNO
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