LVTS-5220-HVX high-voltage battery - BMS alarm page on the battery touchscreen (LVTOPSUN BMS protection alarms)
LVTopsun DsgRly OT error code
The discharge relay temperature exceeded the BMS limit.
Likely causes
- High continuous discharge current through the relay
- Poor relay contact resistance or a worn relay
- High ambient temperature or poor ventilation
- Temperature sensor fault
Checks to run, in order
- 1Check the discharge current against the datasheet
- 2Check the relay temperature reading when the battery is cool
- 3Check ambient temperature and cabinet ventilation
- 4Review the event history for repeated high-current discharge
Fixes
- Reduce the load or discharge current
- Improve ventilation
- Restart after cooling and confirm the alarm does not return at normal current
When to escalate
If the relay over-temperature returns at normal load, ask the distributor to inspect the relay and its connections.
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 DsgRly OT mean?
The discharge relay temperature exceeded the BMS limit.
How do I fix LVTopsun DsgRly OT?
Reduce the load or discharge current Improve ventilation Restart after cooling and confirm the alarm does not return at normal current
When should I escalate LVTopsun DsgRly OT?
If the relay over-temperature returns at normal load, ask the distributor to inspect the relay and its connections.
Can I reset LVTopsun DsgRly OT myself?
Only after isolating the AC and DC sides and running the checks above. If LVTopsun DsgRly OT returns immediately, stop resetting it and escalate; a repeating fault usually points to a real circuit, battery or hardware problem.
Which models show LVTopsun DsgRly OT?
LVTopsun DsgRly OT 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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