How do I fix G98/G99 Grid Disconnect Event on a Enphase?

Check Enlighten for the time of the disconnect event. Cross-reference with grid voltage/frequency at that time Then: For G99 sites, verify grid protection settings are set per DNO approved parameters. Check export limit is active

Enphase

G98/G99 Trip

G98/G99 Grid Disconnect Event

Microinverter(s) have disconnected due to a G98/G99 protection event (over/under voltage or frequency).

Common causes

Voltage or frequency excursion on gridExport causing voltage rise above G98 limitG99 settings incorrectly configured

What to check

STEP 1

Check Enlighten for the time of the disconnect event. Cross-reference with grid voltage/frequency at that time

STEP 2

For G99 sites, verify grid protection settings are set per DNO approved parameters. Check export limit is active

Escalate if

Events are frequent and grid parameters are confirmed within normal range — G98/G99 protection settings may need DNO recertification

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More Enphase fault codes

ACVOOR

AC Voltage Out of Range

ACFOOR

AC Frequency Out of Range

DC Res Low

DC Resistance Low (Ground Fault / GFDI)

DC Too Low

DC Input Voltage Too Low

DC Too High

DC Input Voltage Too High