Charger indicates E04 and refuses to start; installation manual refers to 'phase failure' or 'mains voltage error'

Safety first: Work on the supply side must be carried out by a licensed electrician. Always isolate the circuit before opening covers.

Step-by-step checks:

• 1. Verify supply breaker configuration: Confirm that the correct number of poles (single-phase or three-phase) is installed according to the KEBA charger's rating plate.
• 2. Measure line voltages: With appropriate PPE and tools, measure voltage between phases and phase-to-neutral at the charger input terminals. Compare with local grid standards and KEBA specifications.
• 3. Check phase sequence: For three-phase models, verify correct phase rotation. Incorrect sequence can trigger phase monitoring errors on some KEBA variants.
• 4. Inspect terminal block: With power off, tighten all supply terminals on the KEBA input block. Look for discoloration or melted insulation indicating overheating.
• 5. Cable sizing and length: Ensure that the supply cable cross-section and length are adequate to prevent excessive voltage drop at full load.
• 6. Internal board check: If supply is correct and stable but E04 persists, the internal voltage sensing circuit on the main control board may be defective and require replacement.

Do not operate the charger with known supply irregularities. Correct the electrical installation before returning the unit to service.