Charger displays E17, integrated DC residual current protection test fails or cannot be initiated.

Safety first: Residual current protection is a critical safety function. Do not operate the charger without a functioning DC RCD. Isolate mains before service.

• 1. Run built‑in test:
  • Use the charger’s menu or app to initiate the DC residual current self‑test if available.
  • Note any error messages or codes.
• 2. Inspect sensor:
  • Open the housing and locate the DC residual current sensor ring around the power conductors.
  • Ensure it is properly seated and that all conductors pass through the core as specified.
  • Check the sensor’s connector to the main board.
• 3. Check for damage:
  • Look for cracks in the sensor housing or signs of moisture.
• 4. Firmware update:
  • Check for Heidelberg firmware updates that may address self‑test issues.
• 5. Replace sensor if needed:
  • If E17 persists, replace the DC residual current sensor assembly.
  • If still unresolved, main board replacement may be required.