SUN-5-12K-SG01HP3-EU-DM2 three-phase hybrid (warning codes)
Deye W03 error code
Grid phase-sequence warning.
Likely causes
- Phase sequence reversed at the grid terminals
- Wrong grid-type setting
- One phase missing
Checks to run, in order
- 1Check the phase sequence at the grid terminals
- 2Check the grid-type setting
- 3Check the grid wiring
Fixes
- Correct the phase sequence
- Correct the grid-type setting
- Check the grid-end wiring
When to escalate
If the sequence and settings are correct and W03 persists, the distributor should check the grid detection.
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 W03 mean?
Grid phase-sequence warning.
How do I fix Deye W03?
Correct the phase sequence Correct the grid-type setting Check the grid-end wiring
When should I escalate Deye W03?
If the sequence and settings are correct and W03 persists, the distributor should check the grid detection.
Can I reset Deye W03 myself?
Only after isolating the AC and DC sides and running the checks above. If Deye W03 returns immediately, stop resetting it and escalate; a repeating fault usually points to a real circuit, battery or hardware problem.
Which models show Deye W03?
Deye W03 is documented for SUN-5-12K-SG01HP3-EU-DM2 three-phase hybrid (warning codes). 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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