Display shows E11; charger will not start and may indicate a ground connection problem.

Safety first: Do not use the charger until the ground fault is resolved. Turn OFF the breaker.

• 1. Visual inspection: With power OFF, remove the charger cover and verify that the green/yellow ground wire is securely attached to the ground terminal and metal chassis. Tighten if loose.
• 2. Check supply ground: Have a licensed electrician verify continuity of the ground conductor from the charger back to the main panel. Repair any breaks or loose terminations.
• 3. Inspect for corrosion: Look for rust or corrosion at the ground lug or bonding points. Clean and re-terminate as needed.
• 4. Test with meter (qualified): Measure resistance between the charger chassis and known good ground; it should be very low (near 0 ohms). High resistance indicates a poor ground connection.
• 5. Internal detection fault: If the ground is confirmed good but E11 persists, the ground detection circuit on the main control board may be faulty and require board replacement.

When to call a professional: Grounding issues must be corrected by a licensed electrician. Do not bypass or disable ground detection.