Charger shows E012 and refuses to start; often associated with incorrect wiring or missing ground.

Safety: A proper earth connection is critical for user safety and RCD operation.

• Visual check: With power off, verify that the green/yellow earth conductor is securely connected to the ABB charger’s PE terminal and to the building grounding system.
• Tighten terminals: Tighten the PE terminal screw to the torque specified in the ABB installation manual. Check for corrosion or paint under the ground lug that could increase resistance.
• Measure earth continuity (electrician): An electrician should measure the resistance between the charger PE terminal and the main grounding point; it should be very low (typically <1 Ω).
• Check for broken conductor: Inspect the earth conductor along its route for mechanical damage or splices.
• Control board test: If the earth connection is confirmed good but E012 persists, the PE monitoring circuit on the control board may be faulty and the board should be replaced.