Inverter in Night Mode or Standby — not producing. This is correct behaviour at night or in very low light. Abnormal only if it persists during clear daylight hours.
Common causes
Insufficient irradiance — night or heavy cloud (normal)DC wiring fault preventing string activation (abnormal in daylight)Optimizers not communicating — string voltage too low (abnormal in daylight)
What to check
STEP 1
If dark or overcast: wait — inverter will restart automatically when irradiance returns. No action needed.
STEP 2
In good daylight (>500 W/m²): check DC string voltage with inverter off. Each string should show 1V × number of optimizers. 0V or very low = string break or polarity fault.
Escalate if
Good daylight, P/1/0 switch ON, strings confirmed active but inverter stays in Night Mode after 10 minutes — contact SolarEdge support.
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