IVGM5-8K LP2G1 hybrid inverters (warning code list, flashing fault LED)
Felicity 33 error code
Grid over-voltage alarm: grid voltage is above the inverter's permitted operating window.
Likely causes
- Grid voltage genuinely high at the site
- Utility transformer tap setting too high
- Loose or undersized AC input wiring
- Grid voltage window configured too narrow
Checks to run, in order
- 1Measure grid voltage at the inverter AC input with a true-RMS meter
- 2Measure at the main distribution board to compare
- 3Check the AC input breaker and terminal tightness
- 4Compare the reading with the configured grid voltage window
Fixes
- Wait for the grid voltage to return to range
- Tighten or correct the AC input wiring
- Only widen the grid window within the inverter's safe limits and local rules
When to escalate
If grid voltage is persistently high and outside the distributor-approved settings, escalate to the utility and the distributor.
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 Felicity 33 mean?
Grid over-voltage alarm: grid voltage is above the inverter's permitted operating window.
How do I fix Felicity 33?
Wait for the grid voltage to return to range Tighten or correct the AC input wiring Only widen the grid window within the inverter's safe limits and local rules
When should I escalate Felicity 33?
If grid voltage is persistently high and outside the distributor-approved settings, escalate to the utility and the distributor.
Can I reset Felicity 33 myself?
Only after isolating the AC and DC sides and running the checks above. If Felicity 33 returns immediately, stop resetting it and escalate; a repeating fault usually points to a real circuit, battery or hardware problem.
Which models show Felicity 33?
Felicity 33 is documented for IVGM5-8K LP2G1 hybrid inverters (warning code list, flashing fault LED). Confirm the code on your own unit's display or manual before ordering parts.
More Felicity error codes
- Felicity 04Low cell voltage / over-discharge protection.
- Felicity 05PV over-current fault: the PV input current exceeded the inverter's PV input limit.
- Felicity 18PV short-circuit fault on the PV input; in the warning list the same number means battery under-voltage alarm.
- Felicity 19Battery open-circuit alarm: the inverter no longer detects a battery on its terminals.
- Felicity 20Battery SOC low alarm: the battery's state of charge has fallen to the low-SOC warning threshold.
- Felicity 21BMS communication alarm: abnormal communication between battery and inverter in non-SOC mode.
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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