PV voltage at optimizer input has exceeded maximum allowed input voltage. Displayed fault ID: 004.
Common causes
PV module cable to optimizer unreliable or incorrectOpen-circuit voltage of PV module exceeds optimizer maximum input voltageAbnormal module open-circuit voltage
What to check
STEP 1
Check cables between optimizer and PV module are reliably and correctly connected. Verify Voc of PV module does not exceed optimizer maximum input voltage.
STEP 2
If Voc within spec, check for wiring faults causing voltage spikes.
Escalate if
Connections and Voc confirmed within spec but fault persists — contact Sungrow support
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