BMW Nuisance Tripping / Earth Leakage

BMW EV charger trips the household RCD or main breaker whenever a charging session starts

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Safety Warning

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

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Possible Causes

Combined RCD sensitivity too low for EV charging (e.g., Type A without EV-specific allowance), Cumulative leakage from multiple appliances on same RCD, Faulty internal RCD in BMW Wallbox, Damaged insulation in cable or vehicle inlet

How to Fix / Troubleshooting

Safety first: Repeated tripping indicates a potential safety issue. Do not repeatedly reset without investigation.

  • Isolate the circuit: Ensure the BMW Wallbox is on its own dedicated circuit as required by BMW and local codes.
  • Check RCD type: Confirm with an electrician that the upstream RCD is of the correct type and rating for EV charging (often Type A with DC monitoring in the Wallbox, or Type B).
  • Inspect cable and plug: Look for visible damage or moisture on the BMW Wallbox cable and plug.
  • Test with another EV: If possible, test with a different vehicle to rule out vehicle-side leakage.

If tripping continues with a correct RCD and multiple vehicles, the internal RCD or insulation in the Wallbox may be faulty. A BMW-certified electrician should perform insulation resistance tests and replace the internal RCD module or Wallbox as needed.

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Repair Difficulty

Hard 4/5

Required Part

BMW Wallbox Integrated RCD / Residual Current Monitor
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