Short checklist to make a charging station by yourself using Creasol DomBusEVSE module

Following the instructions below you can make an EV charging station that checks the mains power usage to prevent overload, disconnection and also to use only energy from photovoltaic. DomBusEVSE module, once programmed, can works by itself, in stand-alone mode, without the need of a domotic controller.

  1. Be sure to know what your're doing: you must have knowledge about power dissipation and electric systems. You must be an electric technician to make a wallbox by yourself!
  2. You also must have some computer knowledge and know what is a home automation systems and Modbus protocol.
  3. DomBusEVSE module is the EVSE controller that permits to communicate with the On-Board Charger of your vehicle, for AC charging, single-phase and three-phase: choose the DomBusEVSE version for your need:
    1. with DomBus proprietary protocol, working with Domoticz,
    2. with Modbus standard protocol working with Home Assistant, Node-RED, OpenHAB, and many other home automation systems.
  4. Find below the diagrams for single-phase and three-phase wiring: you need at least a 2P or 4P RCCB (protection) and contactor, the EV cable, and RS485/USB adapter (or RS485/TCP). Components are available in our store, also available in KITs, but as they are standard you can find them everywhere.
  5. It's better to use 10mm² wires for 32A and 6mm² wires for 16A wallbox, to minimize power dissipation on cables. Connections must be checked periodically to ensure that screws are tightened well so that the terminals do not heat up after 15 minutes or more at max charging power!
  6. If you have a home automation system with mains energy meter connected to the domotic controller, measuring the grid power (negative in case that power is exported to the grid), you don't need for another meter connected to the EVSE module: just make a simple automation that periodically sends the current grid power to the EVSE module (every 1-6s).
  7. A power/energy meter measuring the EV charging power/energy is not strictly needed, but recommended. DomBusEVSE supports DDS238-2 ZN/s (single phase) and DTS238-4 ZN/S (three-phase).
  8. RS485 buses require at least 1 termination resistor (100-150 Ohm), and much better a resistor in each bus end: for EVSE-home automation bus, it's possible to enable the resistor by shorting the Rb PCB jumper. For EVSE-energy meters, the resistor is already enabled inside the EVSE module.

More info:


Single phase homemade wallbox EV charging station schematic

Home made wallbox working with Domoticz HomeAssistant, NodeRED, OpenHAB, ...

Three-phase homemade wallbox EV charging station schematic

Three phase home made wallbox for domoticz, home assistant, node-red, OpenHAB, ... using Modbus RTU protocol


Node-RED dashboard for your home-made wallbox using DomBusEVSE module

DIY Home made smart wallbox using Node-RED

Home Assistant dashboard for your wallbox using DomBusEVSE module

  Home made wallbox using Home Assistant

Home made wallbox using DomBusEVSE module, and Domoticz + grafana dashboard

Grafana + Domoticz + DomBusEVSE and DIY wallbox

Solar inverter, V>=253V in the Summer and power limiting/disconnecting

When the solar inverter is feeding a high power (current) to the electric grid, the voltage raise to a high value. Solar inverters are usually programmed to disconnect or limit their output power to avoid output voltage greater than 253V (230V+10%).

To prevent this problem, when a vehicle is at home, just charge it; if the car SoC is almost full, to have a longer charging session, set DomBusEVSE in Solar mode (use only energy from solar inverter) and set EVMAXCURRENT to a low value (in the range 6-32A, for example 12A) to keep mains voltage below 253V.

Also, it's possible to create an automation, in your home automation system, that sets EVMAXCURRENT to a low value when the car is almost full, and full value (16A or 32A depending by your cable and your needs) when the car have to be charged quickly.

Limiting charging power to have a longer session