Charger shows E03 and does not energize the contactor; no charging current flows

Safety first: The main contactor switches high current. Always isolate the charger at the upstream breaker and verify absence of voltage before touching internal components.

Step-by-step checks:

• 1. Listen for contactor operation: When a charging session should start, you should normally hear a distinct 'click' from inside the KEBA unit. If E03 appears with no click, the contactor may not be energizing.
• 2. Visual inspection (power off): Open the housing and locate the main contactor. Check for discoloration, melted plastic, or signs of overheating on terminals and surrounding wiring.
• 3. Tighten terminals: With power still off, gently tighten all line and load terminals on the contactor using the correct torque. Loose connections can cause overheating and mis-detection.
• 4. Coil resistance test (qualified person): Disconnect the contactor coil wires and measure coil resistance with a multimeter. An open circuit indicates a failed coil; a very low resistance may indicate a short. Compare with manufacturer specs.
• 5. Check control signals: If the coil is OK, verify that the main control board is providing the correct control voltage to the coil when a charge is requested. This requires live testing and should only be done by a qualified technician.
• 6. Replace faulty parts: Replace a defective main contactor. If the contactor is good but not being driven, replace or repair the main control board or its contactor driver circuit.

Do not attempt to manually force the contactor closed. If in doubt, involve a KEBA-authorized service provider.