Partner Academy · EcoBSS / FLEX
Fault
3P LV
F48
AC_UnderFreq_Fault
AC under-frequency fault
EcoBSS service: AC under-frequency (grid out of range).
Register map
- Family
- Three-phase LV (FLEX 3L)
- Register
- 557
- Bit
- 15
Field checks
- Check that grid frequency is within specification.
- Check AC cables and their connections.
- Contact Inversol if the problem repeats.
FAQ
What does EcoBSS F48 mean?
AC under-frequency fault
What should I check for EcoBSS F48?
- Check that grid frequency is within specification.
- Check AC cables and their connections.
- Contact Inversol if the problem repeats.
When should I contact Inversol?
Confirm LV vs HV family on the nameplate, complete the field checks, then contact Inversol with model, SN, family, and a photo if the code returns after a clean power cycle.
Partner lookup from EcoBSS Flex register map V1.2 — not a substitute for the official service manual or live measurements. Always match the inverter family (3P LV / FLEX 3L vs 3P HV).