LVTS-5220-HVX high-voltage battery - BMS alarm page on the battery touchscreen (LVTOPSUN BMS protection alarms)
LVTopsun Commu Flt error code
The BMS lost communication with the inverter or with another module in the stack.
Likely causes
- CAN or RS485 cable disconnected, damaged or miswired
- Wrong protocol selected on the battery or inverter
- Missing or incorrect termination resistor
- BMS or inverter communication board fault
Checks to run, in order
- 1Check the CAN cable between battery and inverter, and between modules
- 2Confirm the protocol selected on the battery matches the inverter brand
- 3Check termination and shield/earth of the communication cable
- 4Check the inverter battery type and communication status screen
Fixes
- Reseat or replace the communication cable
- Select the correct protocol on the battery touchscreen and restart
- Fit the correct termination resistor
When to escalate
If communication does not return with a known-good cable and correct protocol, ask the distributor to check the BMS communication board.
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 Commu Flt mean?
The BMS lost communication with the inverter or with another module in the stack.
How do I fix LVTopsun Commu Flt?
Reseat or replace the communication cable Select the correct protocol on the battery touchscreen and restart Fit the correct termination resistor
When should I escalate LVTopsun Commu Flt?
If communication does not return with a known-good cable and correct protocol, ask the distributor to check the BMS communication board.
Can I reset LVTopsun Commu Flt myself?
Only after isolating the AC and DC sides and running the checks above. If LVTopsun Commu 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 Commu Flt?
LVTopsun Commu 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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