Siemens
Supply Voltage Sag / Internal Power Instability
Charger’s front LEDs or display flicker or dim when a vehicle is connected or when other household loads switch on.
Advertisements
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.
Advertisements
Possible Causes
Undersized supply cable causing voltage drop, Loose neutral connection, Overloaded household circuit sharing with charger, Failing internal auxiliary power supply
How to Fix / Troubleshooting
Safety first: Voltage sags can damage equipment. Have an electrician evaluate the supply.
- Dedicated circuit: Ensure the Siemens charger is on a dedicated circuit as specified in the installation manual.
- Measure voltage: Under load, measure voltage at the charger input. If it drops below the minimum specified, upgrade wiring or reduce charger current setting.
- Check neutral: Tighten neutral and earth connections at both the charger and distribution board.
- Internal PSU check: If supply is stable but LEDs still flicker, the internal power supply on the control board may be failing and require replacement.
Advertisements
Repair Difficulty
Medium
3/5
Required Part
Supply Wiring / Main Control Board Power Supply
Check Price on Amazon
We may earn a commission from links on this page.
Advertisements