SG04LP3/SG05LP1 hybrid families and SG01HP3-EU-DM2
Deye F18 error code
AC overcurrent detected by hardware.
Likely causes
- Backup load above the inverter rating
- Output short circuit
- Large motor starting surge
- Grid voltage sag
Checks to run, in order
- 1Clamp the backup and common load current
- 2Check the backup output for a short
- 3Measure the grid voltage
- 4Check load balance
Fixes
- Reduce or stagger the load
- Clear the output short
- Restart and retest
When to escalate
If the load is within rating and F18 recurs, the AC current sensor or output stage needs distributor service.
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 Deye F18 mean?
AC overcurrent detected by hardware.
How do I fix Deye F18?
Reduce or stagger the load Clear the output short Restart and retest
When should I escalate Deye F18?
If the load is within rating and F18 recurs, the AC current sensor or output stage needs distributor service.
Can I reset Deye F18 myself?
Only after isolating the AC and DC sides and running the checks above. If Deye F18 returns immediately, stop resetting it and escalate; a repeating fault usually points to a real circuit, battery or hardware problem.
Which models show Deye F18?
Deye F18 is documented for SG04LP3/SG05LP1 hybrid families and SG01HP3-EU-DM2. Confirm the code on your own unit's display or manual before ordering parts.
More Deye error codes
- Deye F01PV input polarity is reversed at one or both DC inputs.
- Deye F02PV insulation resistance to earth is below the safety limit.
- Deye F03Ground fault detected on the PV array (GFDI).
- Deye F04GFDI ground-failure alarm: the PV array or inverter is not properly earthed.
- Deye F05Control-board EEPROM read failure.
- Deye F06Control-board EEPROM write failure.
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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