The inverter raises a per-input alarm that a specific PV input or string is abnormal. The fault code tells you which input or string is affected. Start by comparing the voltage and current of the flagged input with the other inputs to narrow down the cause. If that input is not meant to have a string connected, you can ignore the alarm. If it should be connected, check that the connection is secure and tighten any loose wiring. Check the DC fuse for that input and replace it if it is blown. If the current is low, look for shading or soiling on the string's modules and clean or remove it. Also check the modules for abnormal aging. If none of these causes is found and the alarm stays active, contact Sungrow service.
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observed_asc1 drafted · lead String current below average
On SG-CX-US units, codes 548-563 and 580-587 are reported as a string output current anomaly. The manual lists shading, soiling and abnormal module aging as causes to check.
tbl=55.r2 h=f64097f39f10tbl=55 h=984f64a5a050c2 verified · fact Low string performance ratio
Normalized string DC current is compared with the best-performing string on the same component. An alert opens when a string stays below the set ratio for the time threshold in daylight hours.
sec=h3 h=d9fd72a0a2fasec=h2 h=4ec2fde2d167verified by: review-workflowverified on: 2026-10-20
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