Abnormal voltage or current on a PV string. IDs 548–563 = strings 1–16; IDs 580–595 = strings 17–32. System continues operating but affected string is degraded.
Common causes
PV modules shaded or soiledLoose wiring on panel junction box or combinerDC fuse blown or damagedModule degradation or failure
What to check
STEP 1
Check whether affected string's modules are shaded or dirty. Remove shading sources and clean panels if needed.
STEP 2
Inspect string wiring — check all connections are securely seated. Check DC fuse(s) for the string — replace any blown fuse.
Escalate if
Shading, cleaning, wiring, and fuse checks all pass but alarm persists — contact Sungrow support
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