Low insulation resistance detected between PV array and earth. Often morning condensation false positive.
Common causes
Condensation on panels or MC4 connectors (morning only)Damaged PV cableFaulty panelWet MC4 connector
What to check
STEP 1
If morning only and self-clearing: condensation false positive -- update firmware. If daytime: measure PV+ and PV- to Earth (both should exceed 100 Mohm).
Escalate if
Daytime fault with impedance below 100 Mohm -- cable and panel inspection required
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