SUN-5-12K-SG01HP3-EU-DM2 three-phase hybrid (F-series table)
Deye F27 error code
DC insulation fault reported by the second detection path.
Likely causes
- Damaged PV cable or connector insulation
- Moisture in the array wiring
- Inverter PE not connected
- Insulation-detection circuit fault
Checks to run, in order
- 1Megger the PV strings to earth
- 2Inspect DC cables and connectors
- 3Check the inverter PE bond
- 4Restart and read the fault log
Fixes
- Repair the damaged insulation
- Bond the PE conductor
- Restart three times and restore factory settings
When to escalate
If the array insulation is healthy and F27 persists, the distributor should check the insulation-detection circuit.
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 F27 mean?
DC insulation fault reported by the second detection path.
How do I fix Deye F27?
Repair the damaged insulation Bond the PE conductor Restart three times and restore factory settings
When should I escalate Deye F27?
If the array insulation is healthy and F27 persists, the distributor should check the insulation-detection circuit.
Can I reset Deye F27 myself?
Only after isolating the AC and DC sides and running the checks above. If Deye F27 returns immediately, stop resetting it and escalate; a repeating fault usually points to a real circuit, battery or hardware problem.
Which models show Deye F27?
Deye F27 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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