LVTS-5220-HVX high-voltage battery - BMS alarm page on the battery touchscreen (LVTOPSUN BMS protection alarms)
LVTopsun System Flt error code
The BMS reported an internal system fault that is not covered by a specific alarm.
Likely causes
- BMS firmware or configuration fault
- Internal communication fault between BMS boards
- Hardware fault on the BMS board
- Fault triggered by another alarm in the event log
Checks to run, in order
- 1Read the Current Event and History Event pages for the alarms that preceded it
- 2Power-cycle the battery once and recheck
- 3Check the CAN and sense harness connections
- 4Note the firmware version shown on the SN Info page
Fixes
- Clear the fault by restarting once, after fixing any preceding alarm
- Record the event log and firmware version for the distributor
- Keep the battery isolated until the cause is identified
When to escalate
If the system fault returns with no other alarm in the log, give the distributor the event log and firmware version so they can check the BMS.
Fix it with the right tools
Check the system around the fault before replacing parts: load, battery bank, PV string and commissioning settings. If you need a second opinion, send the code and your inverter model to our team.
Before you open the inverter
- Isolate both the AC and DC sides, then confirm the display is dead before touching terminals.
- Use insulated tools and one hand where possible. DC arcs do not self-extinguish like AC.
- If you see burnt terminals, swollen cells, leaking electrolyte or a burning smell, stop and escalate instead of resetting the fault.
Questions installers ask
What does LVTopsun System Flt mean?
The BMS reported an internal system fault that is not covered by a specific alarm.
How do I fix LVTopsun System Flt?
Clear the fault by restarting once, after fixing any preceding alarm Record the event log and firmware version for the distributor Keep the battery isolated until the cause is identified
When should I escalate LVTopsun System Flt?
If the system fault returns with no other alarm in the log, give the distributor the event log and firmware version so they can check the BMS.
Can I reset LVTopsun System Flt myself?
Only after isolating the AC and DC sides and running the checks above. If LVTopsun System Flt returns immediately, stop resetting it and escalate; a repeating fault usually points to a real circuit, battery or hardware problem.
Which models show LVTopsun System Flt?
LVTopsun System Flt is documented for LVTS-5220-HVX high-voltage battery - BMS alarm page on the battery touchscreen (LVTOPSUN BMS protection alarms). Confirm the code on your own unit's display or manual before ordering parts.
More LVTopsun error codes
- LVTopsun Ahesion FltThe BMS detected a main contactor or relay that has stuck closed (contact adhesion).
- LVTopsun Chg Bat Ov_VThe pack voltage rose above the BMS charge over-voltage limit.
- LVTopsun Chg Bat Ud_VPack voltage stayed below the BMS charge under-voltage limit while the pack was supposed to be charging.
- LVTopsun Chg Cell Ov_VCharging was stopped because a cell reached the BMS charge over-voltage limit.
- LVTopsun Chg Cell Ud_VA cell fell below the BMS charge under-voltage limit while the pack was being charged.
- LVTopsun Chg Diff_TThe temperature difference between BMS sensors exceeded the limit during charge.
Guidance reviewed 17 October 2026 by the Mishka Energy installer team. Error codes vary by brand, model family and firmware; confirm against the manufacturer manual.
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