Sungrow
SG-009 · ID 323
Grid Confrontation
BACK-UP port has been connected to the actual utility grid — not permitted. Prevents dangerous interaction between inverter off-grid output and grid.
Common causes
BACK-UP port incorrectly wired to grid instead of backup/critical loadsWiring error during installation
What to check
STEP 1
Check AC wiring — confirm BACK-UP port is NOT connected to utility grid.
STEP 2
Disconnect BACK-UP port from grid if incorrectly wired. Reconnect to backup/critical loads only.
Escalate if
Wiring corrected but fault persists — contact Sungrow support
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