Tesla Wall Connector - Click Sound

Tesla Wall Connector - Click Sound

Hi All,

I just had a Tesla Wall Connector installed for 60 AMP - 240 volts charging. I have my 2017 Model S set to 48 amps.

When I 'plug' the charger into my Tesla, the Wall Connect makes a single loud 'click' sound before it begins to charge. It charges properly and the green light scrolls down so everything seems to working properly.

Is the single 'click' sound normal?


reed_lewis | February 7, 2019

Yes. That is the relay energizing to allow the power to go to the car.

DanFoster1 | February 8, 2019

Indeed as reed_lewis said, that is the sound of the relay switching the AC power on after the car instructs it to do so. I like the sound of the relay click—it lets me know if I’ve set scheduled charging or not.

The relay only switches the AC current on when the car pairs with the HPWC, so it’s damn-near impossible to electrocute yourself with a HPWC. The relay is also quite robust since up to 80 amps continuous at 240 volts flows through it under the right circumstances. It’s similar (but smaller) to the contactors that switch on the high voltage battery array in the car itself.

This video shows the relay (contactor) about 5m 35s in:

Note: The video is labeled High Powered Wall *Charger but this is incorrect, the HPWC is a *connector, not a charger. The HPWC is basically a robust extension cord, with multiple features for user protection built in—but it’s not a ‘charger,’ —the ‘charger’ is the computer controlled AC to DC converter inside the car.