Creasol DomBusEVSE  is a full features, fully tested and CE certified DIN rail module, designed for Domoticz and Home Assistant, but working even with OpenHAB, Node-RED, ioBroker and other home automation systems, to  charge electric vehicles using the standard SAE 1772 and IEC 62196-2  Mode3  (AC charge, up to 22kW power).

It works as  stand-alone  (with or without any domotic controller: in this case the charging current is controlled by the EVSE module) or in  managed mode   (the charging current is set by a domotic controller / automation, so in this case the EVSE works in "stupid mode").

Note: if you're reading a translated page, please consult the English version to get the most up-to-date version.

WARNING: Working with 230V/400V AC is extremely dangerous. 
This project should only be carried out by qualified individuals or under the supervision of a licensed electrician.
Always ensure your installation complies with local regulations.

Build Your Smart DIY EV Wallbox with DomBusEVSE, solar-aware, providing a lot of functions under your control!

DomBusEVSE is a versatile, high-performance module designed to build a custom Electric Vehicle Charging Station (EVSE) that integrates seamlessly with your home automation system (Domoticz, Home Assistant ...). Unlike "dumb" wallboxes, this DIY solution allows for total control over charging currents and solar diversion.

With DomBusEVSE you don't need to install another energy meter or current clamp, if you already have one connected to your domotic controller or if you have a hybrid solar inverter: it's sufficient a simple automation to inform EVSE about the current grid power, or power from grid + power from static battery, allowing single phase (1000÷7360W) and three phase (3500÷22000W) EV charging preventing grid overload.

Features

• Mode 3 charging, AC
  230V (single-phase, up to 7.36kW) or
  AC
  400V (three-phase, up to 22kW) or both (it can manage tow 2P contactors, to activate single phase charging when low power is available, and switch to three-phase charging when the available power increases: this feature may be useful in Solar mode to charge using low power, in single phase, or high power (in three phase, when more than 7kW is available)
  
• Manages up to 2 Modbus energy meters DDS238-2 ZN/S (single phase, very accurate class-1 meters) or DTS238-4 ZN/S (three phase), one to measure the charging power/energy, one to measure the power/energy exchanged with the electricity grid. As energy meters are really accurate (class 1), it's possible to get accurate statistics and charts about the energy used to charge the electric vehicle and energy exchanged with the grid.
• Controls an external 2P or 4P contactor to enable or exclude mains power supply to the electric car, and fully check that contactor works as expected (alarm in case of concacts welded or power outage).
• 5 working modes, that can be configured by the domotic controller (Domoticz, Home Assistant, Node-RED, OpenHAB, ... or by Modbus), and also by a UP/DOWN buttons (on the module, but a UP/DOWN button can be also connected externally):
  • OFF: EV charging disabled (led status: red)
  • SOLAR: use only energy from the solar system, assuring that power from grid is less equal than 0 Watt (Grid Power < 0; led status: green).
  • 25%: use both solar and grid energy, max 25% of the power availability (for example, with 6kW contract, use max 1500W from grid, + available power from solar) (Grid Power < 0.25*EVMAXPOWER; led status: yellow)
  • 50%: use both solar and grid energy, max 50% of the power availability (for example, with 6kW contract, use max 3kW from grid) (Grid Power < 0.5*EVMAXPOWER; led status: yellow)
  • 75%: use both solar and grid energy, max 75% of the power availability (for example, with 6kW contract, use max 4500W from grid) (Grid Power < 0.75*EVMAXPOWER; led status: yellow)
  • 100%: use both solar and grid energy, max full power (for example, with 6kW contract, use max 6kW) (Grid Power < EVMAXPOWER; led status: yellow). In this mode it's also possible to set a consumption profile which includes two maximum power thresholds which are alternated for the duration of two configured times, to use the really max power from the grid. For example, in Italy with a 6kW contract it's possible to drain max 7.6kW for 90 minutes, than 6.6kW for 90 minutes.
  • MANAGED: charging current set by the domotic controller (by a script, for example) (led status: blue).
• From SOLAR to 100% mode, the EVSE set the charging current based on the current power drained from the Grid (if the grid meter is directly connected to the EVSE). In case that a grid meter is already installed in the building, or in case of hybrid inverter with photovoltaic inverter + accumulator is installed, it's possible to avoid installing another meter and set a simple automation that pass the GridPower value to the EVSE, or pass the EVGridPower = GridPower - BatteryPower to the EVSE: in the latter case, the EVSE in Solar mode will use only energy from photovoltaic, without discharging the static battery.  
  Example (solar power decreases): EVSE in Solar mode, GridPower = 500W (500W from the grid), BatteryPower = -200W (200W from the battery to the inverter) => EVGridPower = 500 - (-200) = 700 : when the EVSE receive EVGridPower = 700 in solar mode, it reduces EV power by 700W to keep EVGridPower=0.
  Another example (solar power increases):  GridPower=-200 (200W to the grid), BatteryPower=1000 (1000W from the inverter to the battery) => EVGridPower = -200 - 1000 = -1200 => EVSE will increase the charging power by 1200W
  Another example (charging at full speed: EVMode=100%): EVMaxPower=8000, GridPower=7000, BatteryPower=1000 (inverter is sending 1000W to the battery) => sending EVGridPower=7000 - 1000 = 6000  to the EVSE, it increases charging power by 2000W to saturate the Grid power, having 8000W from Grid going to the EV.
  For an even higher degree of customization, it's possible to set the EVSE in Managed mode: in this way the EVSE module becomes dummy (does not manage the charging current by itself, but needs an external automation that sets the charging current), permitting any type of charging method (for example the case of multiple optimized wallboxes connected together).
• EVMinVoltage: it's possible to configure this parameter to keep the charging voltage at a fixed value: for example, in single phase, setting EVMinVoltage=248V the EVSE will charge the vehicle at the minimum current needed to keep voltage at that value. This is very useful when vehicle battery is almost full and we want to avoid invert overvoltage protection (power derating or inverter OFF) caused by V>=253V (excess production, during sunny days in the weekend). Check the video!
• STOP charging by pushing DOWN button for 1 second
• AUTOSTART function:
  AUTOSTART=0 -> EVMode can be changed only manually, by smartphone or UP/DOWN buttons
  AUTOSTART=1 -> when the vehicle is plugged, EVMode is restored to the previous charging mode. For example, vehicle is charging in SOLAR mode, push DOWN button for 1s to stop charging, unplug the vehicle to go away; when vehicle is plugged again, EVMode is automatically set to SOLAR mode (last mode).
  AUTOSTART=2, when vehicle is unplugged, EVMode goes OFF and can be enabled only by smartphone/domotica or UP/DOWN buttons. This is a useful feature when wallbox is placed in a common area and we want that only authorized people can charge.
• Possibility to limit charging power by setting EVMAXCURRENT device to a value less than cable limit (32A or 16A).
• the domotic controller (Domoticz, Home Assistant, OpenHAB, ...) can receive from DomBusEVSE module the following telemetries for real-time display and to show nice charts:
  - charging power/energy, that is differentiated into the following two charts
    - charging power/energy from solar (photovoltaic or other renewable source)
    - charging power/energy from the electricity grid
  - charging voltage and power factor (the latter is useful to detect the minimum power to get high efficiency from the on board charger)
  - total power/energy from grid
  - grid voltage, power factor and frequency
• RGB led displaying current EV state:
  EV unplugged/disconnected: 1 green flash  (CP voltage = 12V)
  EV plugged/connected: 2 green flashes (CP voltage = 9V)
  EV plugged/connected and EVSE wants to start charging: 3 green flashes (CP voltage = PWM +/- 9V)
  EV charging: blue led flashes 1 or more times, indicating the current power (1 blue flash => less than 1kW, 2 blue flashes => less than 2kW, ...) (CP voltage = PWM +/- 6V)
  EV error: 1 red flash => On board charger requires external ventilation, 2 red flashes => no mains power supply detected by EVSE module (EV Supply input should be connected to 230V output from contactor), 3 red flashes => mains power supply detected when contactor is OFF: welded contact?
  When a new EV mode is selected (from smartphone or using the UP/DOWN button), RGB led shows current mode for 1 second.
• Low power consumption: 100mW in stand-by, 400mW while charging
• Terminal blocks to connect external Up/Down double-pushbutton, if needed, that works with the same function of the internal UP/DOWN button (setting EV Mode).
• Size: DIN-rail, 3 modules width, 53x89x65mm
• Connection: RS485 (DomBus or Modbus protocols), using common alarm cable (4x0.22mm² or 2x0.22mm²+2x0.5mm²); max connection length: 200m

Supported protocols

DomBusEVSE is available with 2 different firmwares, supporting the following protocol:

• DomBus, an optimized low-latency protocol for Domoticz controller (using a python plugin), or with other home automation systems (Home Assistant, OpenHAB, Node-RED, ioBroker, ...) that supports MQTT AutoDiscovery, by using the DomBusGateway service (a python program running in background or a Home Assistant app, that converts DomBus data in MQTT and vice-versa).
  When connecting the DomBusEVSE module, programmed with DomBus firmware, to Domoticz or any system supporting MQTT-AutoDiscover like Home Assistant, all entities are immediately visible.
• Modbus RTU, a standard protocol that can be used with almost any home automation systems

DomBus is better, needing a connection to the module by a USB/RS485 adapter, by a WiFi/LAN/RS485 module supporting virtual serial port, or by an additonal microcomputer using DomBusGateway software (a bridge between DomBus and MQTT).

Modbus protocol is good in case of using non-standard domotic systems that does not support MQTT,  when connecting by a WiFi/LAN/RS485 module supporting only ModbusTCP protocol, or when the system is used without any domotic system or controlled by a custom program.

How to make a home-made EV charging station / wallbox

To make a DIY wallbox / EV charging station the following items are needed:

• Type-EV or Type-B RCCB: a residual current protection, with 6mA DC current detector
• optionally (but recommended), a power meter to monitor and account the energy, power, voltage and power factor to the vehicle
• a contactor to enable/disable mains power
• a EVSE module that sends a PWM signal to the On Board Charger (inside the vehicle) to specify the max available power (current) to avoid avoiding overloads and get load balancing
• a connection between the EVSE module and a power / energy meter that measures the power exchaged with the electrical grid. If the energy meter measuring grid power already exists in your home automation system, you don't need to add another energy meter: just use a simple automation to send the actual power (every 6s or less) to the Grid Power virtual device/entity of the EVSE module.

Making a wallbox is quite simple: mains power is connected to the RCCB (protection from residual current) + optional (but recommended) energy meter + contactor + EV cable. Care should be taken to avoid overheating on wirings and connections, that should be periodically checked!!
The EVSE module is connected to the control-pilot wire of the EV cable, monitors the presence of voltage (on contactor output) and enable/disable the mains power contactor. Also, it may communicate with the main grid power energy meter or, alternatively, with the domotic controller to get the current grid power from the existing energy meter.

Actually DomBusEVSE is able to read DDS238-2 ZN/S energy meter (single phase) and DTS238-4 ZN/S (three phase) to get the current grid power; if a single-phase or three-phases energy meter (or hybrid solar inverter) already exists and it's connected to a domotic controller (like Domoticz, Home Assistant, ...), it's possible to create a simple automation to send to DomBusEVSE, every 6 seconds or less, the current grid power (positive if imported, negative if exported), so the EVSE can do load balancing correctly.

It's also possible to use DomBusEVSE to build a very cheap charging station with no energy meters at all, by setting the parameter EVMETERTYPE to 2 (for single phase) or 3 (three phase): in this case EVSE will not manage load balancing, but simply will charge the vehicle using 25,50,75 or 100% of the power set by EVMAXPOWER parameter.

More info at www.creasol.it/EVSE (complete info about the module) and www.creasol.it/EVSEHA (for Home Assistant users)

• Availability: 60 In Stock
• SKU: creDomBusEVSE