Display shows E16 and the charger may beep or flash a warning icon; charging does not start.

Safety first: An insulation fault can lead to electric shock. Immediately disconnect power and do not use the charger until the issue is resolved.

• 1. Inspect for moisture: Check the connector, cable, and charger housing for signs of water, condensation, or corrosion. Dry thoroughly and allow time for internal moisture to evaporate.
• 2. Look for physical damage: Examine the cable jacket and internal wiring (if accessible) for cuts, burns, or crushed areas.
• 3. Environmental check: If the charger is installed outdoors, ensure that all gaskets and seals are intact and that the unit is rated for outdoor use. Protect from direct spray and pooling water.
• 4. Megger test (technician): A qualified technician can perform an insulation resistance test between conductors and ground to locate the fault.
• 5. Replace damaged components: Replace any compromised cable, connector, or internal wiring. If the isolation monitoring circuit itself is faulty, the main control board may need replacement.