Today we had a strange fault, which we couldn't understand. We have a 3-phase system built with 3 Quattro 48/15000. The system was running fine for 3 months.
We know physically that on the L1 the customer created a shortcircuit in one of his loads, so that the system shutdown. However when we asked for a photo, we have observed that the Quattro on the L2 was in overload state, blinking the red led of overload.
We went on site, fixed the shortcircuit on the L1 loads and restarted the system again. However L2 wouldn't start and Cerbo showed on the screen that L2 has an overload. even after removing all cables from L2 (except for the battery), it still showed overload.
attached the pictures
cerbo_L2_overload.jpegVRM_L1_overload.png
Hence we demounted the Quattro on the L2 for bringing to service. We reconfigured the remaining 2 Quattros in paralell. On that evening when I checked the data in VRM, I saw under VE Bus state, that indeed L1 had the overload, nothing mentioned about L2. Indeed L2 had barely any loads since commissioning. (around 100Watt)
This is really confusing. Any advice ? We really tried everything we could, shutdown everything (solar chargers, batteries) restart etc. But the quattro on the L2 wouldn't start.
Best regards