Charger displays E03, charging stops or will not start, often after a power fluctuation or grid disturbance.

Safety first: Only a qualified electrician should open the supply terminal area. Always isolate the charger at the main breaker and verify de‑energized state.

• 1. Confirm supply configuration:
  • Check the Heidelberg installation manual for the correct wiring diagram (single‑phase vs three‑phase).
  • Verify that L1, L2, L3, N, and PE are connected as required for your model.
• 2. Measure input voltage:
  • With a multimeter, measure line‑to‑line and line‑to‑neutral voltages at the charger’s terminal block.
  • Ensure voltages are within the specified range (typically 230 V ±10% single‑phase or 400 V ±10% three‑phase).
• 3. Check terminal tightness:
  • Inspect all terminal screws on the input terminal block for looseness.
  • Retighten to the torque specified by Heidelberg to avoid overheating and intermittent faults.
• 4. Verify configuration switches:
  • Some Heidelberg chargers use DIP switches or software settings to select supply type.
  • Ensure the configuration matches the actual wiring (e.g., 1P vs 3P).
• 5. Reset and test:
  • After corrections, power cycle the charger at the breaker for at least 60 seconds.
  • Check if E03 clears and a charging session can be started.