SUN-5-12K-SG01HP3-EU-DM2 three-phase hybrid (F-series table)
Deye F40 error code
Internal DC overcurrent.
Likely causes
- DC bus short circuit
- Severe DC overload
- Power-stage hardware fault
Checks to run, in order
- 1Check the DC bus and battery wiring for a short
- 2Check the battery and PV current
- 3Restart the inverter
Fixes
- Clear the DC fault and reduce the load
- Restart the inverter
When to escalate
If F40 returns with correct DC wiring and current, the distributor should service the power stage.
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 F40 mean?
Internal DC overcurrent.
How do I fix Deye F40?
Clear the DC fault and reduce the load Restart the inverter
When should I escalate Deye F40?
If F40 returns with correct DC wiring and current, the distributor should service the power stage.
Can I reset Deye F40 myself?
Only after isolating the AC and DC sides and running the checks above. If Deye F40 returns immediately, stop resetting it and escalate; a repeating fault usually points to a real circuit, battery or hardware problem.
Which models show Deye F40?
Deye F40 is documented for SUN-5-12K-SG01HP3-EU-DM2 three-phase hybrid (F-series table). 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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