Question about AUX

[dialmak]

Hi, The configuration https://github.com/dzurikmiroslav/esp32-evse/blob/master/cfg/esp32devkitc/board.cfg says

#AUX
AUX_IN_1=y
AUX_IN_1_NAME=IN1
AUX_IN_1_GPIO=4

AUX_IN_2=y
AUX_IN_2_NAME=IN2
AUX_IN_2_GPIO=21

....

AUX_OUT_2=y
AUX_OUT_2_NAME=OUT1
AUX_OUT_2_GPIO=5

Вut in the electrical circuit https://oshwlab.com/dzurik.miroslav/esp32-devkit-evse these contacts GPIO=4,5,21 are not used. These are optional functions, I think, but I want to clarify what role they play and how to correctly connect external connections to the board. I want to repeat the electrical circuit, first single-phase, then three-phase .... The software was reproduced, and everything works. Thank you.

[dzurikmiroslav]

Hi, Yes you have right, these GPIOs are not used in that circuit. I commit that by mistake, when I was developing AUX script API...

[dialmak]

Ок. In a three-phase circuit, they are (I think) necessary. But what exactly and how is connected through these contacts AUX. Can I get a schematic or wiring? Thank you.

[dzurikmiroslav]

No, AUX are for additional input/output functionality (for example: enable charging in low tariff, limit charging current by button, show external status light when charging, etc...) controller in script driver (Berry lang). ESP32-DevKitC board has single-phase energy meter (current transformer + voltage sensing), can you use in three-phase wallbox, but will not have real power & energy consumption. You can set energy meter type to "Dummy three phase", power & consumption will be calculated from provided AC voltage and actual Charging current. I was thinking that in the future I will add support for an external energy meter with RS485 modbus interface...

[dialmak]

Thanks. I understood about AUX.

Which current transformer do you recommend?

[dzurikmiroslav]

Any which has ratio 2000/1 In esp32-devkit-evse I was using SCT-013-000 (has jack connector) In esp32s2-evse-d-a I was using DL-CT08CL5 0-120A (no connector)

[dialmak]

Thanks.

The last question remains on the electrical circuit. I want to add an electronic residual current device to the single-phase version. What circuit and sensor do you recommend? Is it possible to use the residual current device circuit from the three-phase version?

[dzurikmiroslav]

esp32s2-evse-d-a has RCM input for RCM14 https://webshop.westernautomation.com/ev-industry/rcm14-03-6ma-dc-15-30ma-ac-9013

esp32-devkit-evse has no RCM input, only option is use standard electrical residual current breaker (type B or other for EV) for example: https://www.se.com/ww/en/product/A9Z51440/residual-current-circuit-breaker-rccb-acti9-iid-4p-40a-bev-electric-vehicle-type-30ma-double-terminal/

Other way is design custom board, for example based on esp32-devkit-evse and extend with RCM circuit form esp32s2-evse-d-a and write config for it.