Tesla Wall Connector Gen2 box revived with ESP32-EVSE

[nagyrobi]

Found a broken Tesla Wall Connector GEN2, which has an exceptionally well built casing. Fire resistant and IP67 protected and also looking very good.

This box can accommodate ESP32‐S2 EVSE DIY ALPHA very well. It fits into the upper area of the box, while the contactor and the optional surge protector can go in the lower area. The mid space is just enough to host the RCM and the current transformers.

To hold the board and the DIN rail components you need to 3D print some parts. The board holder is tightened to the bottom of the box, in the original screw holes, but with longer M3 and M4 screws. The DIN rail holder screws on similarly with M3 screws.

My Tesla Wall Connector Gen2 had the LED board also broken so I replaced it with a WS2812 LED strip I had left rom room decoration. I used an ESP32C3 SuperMini board to drive it, and re-create light animations similar to how the Wall Connector behaves originally.

Plus benefit is, that with a simple RF transmitter module, 433MHz signals can be used to trigger opening of the charge flap on Tesla vehicles. Using the ESPHome component to interface with ESP32-EVSE not only integration with Home Assistant can be seamlessly achieved, but also implementing a physical button to both open the flap and stop charging (+releasing the cable from the car) thus the factory functionality of the Tesla Wall Connector can be simulated. The holder, spacer and the cover for the stip and the ESP32C3 SuperMini are also 3D printed.

The ESP32C3 SuperMini also handles the reset button on the box, being multifunctional (different functions for short and long-press). ESPHome config here

The contactor is 4NO 63A. I used 7x6mm2 cable to transfer even 22kW if needed. It's cheaper than the EVSE dedicated cables, wires 6 and 7 can carry CP signal from the EVSE board and the button press signal to the SuperMini board. I used a small push button on the plug itself to replicate original location.

I used RCM14-03 to detect AC and DC residual current leaks. I used in-line fuse holders (with glass 5x20mm 32mA fast fuses) for the voltage transformers.

Note: The T3 surge protector is entirely optional and it's only effective if the facility you install this in has T1 and T2 surge protectors installed at the grid entry point and the distribution panel respectively. Using a T3 (or T1/T2) protector on its own will not protect from a lightning surge coming in though the grid. They are only effective as a system where they are deployed at a properly cabled distance from each other.