cFos Charging Manager with and without meter
The cFos Charging Manager always distributes the maximum house connection power to the EVSEs that are actually charging.
EVSE without meter:
The cFos Charging Manager assumes here that the car always uses the entire charging current offered. You can use the "Phases" option to set the phases with which the car charges. If the car does not accept the power offered in this way, the Charging Manager cannot make it available to other cars.
EVSE with S0 meter:
The cFos Charging Manager knows at which power the car is currently charging and can make unclaimed power available to other cars. Since S0 meters only send pulses per kWh, the Charging Manager cannot know on which phase charging is taking place. You should use the "Phases" option to set which phases are actually used. Since the cFos Charging Manager looks at the charging currents for all 3 phases individually, it can then allocate the available current to cars charging on other phases.
You should definitely connect several EVSEs with phase rotation to avoid peak currents on individual phases and also inform the cFos Charging Manager of this in the EVSE configuration under "Phase rotation". If you charge different vehicles that use different phases, inaccuracies may occur and you should set a control reserve in the cFos Charging Manager settings.
EVSEs with attached meter:
If the EVSE does not have a meter, you can (have) an external meter installed in the supply line, add it as a device in the cFos Charging Manager and then "pin" it in the EVSE settings of the EVSE. This EVSE will then appear to the cFos Charging Manager as one with a built-in meter.
cFos Power Brain Wallbox:
The cFos Power Brain Wallbox is available with either a built-in or external meter. If you want to use the external meter to measure the EVSE power, you should attach it (see above). For cFos Power Brain Wallboxs that are operated as slaves, you should attach the meter in the slave. The EVSE will then appear as a EVSE with a built-in meter.
Meter for domestic consumption:
Without a consumption meter, the cFos Charging Manager cannot know how much the domestic connection is really loaded with its maximum power. In this case, you must enter the power that is available to the EVSE at all times as the maximum house connection power in the Charging Manager settings, regardless of which other consumers exist -> Static load management. In many cases this is sufficient. In many cases, however, the available household power is only used as household consumption at peak times and can be used to charge the cars during the remaining hours. In this case, it is advisable to install a meter that measures the household consumption without the EVSE. It is best to install a 3-phase resolving meter, otherwise you will have to plan for a power reserve. Then, in the cFos Charging Manager settings, enter the value that you have ordered from your energy supplier for your house as the maximum house connection power. The cFos Charging Manager then makes this power, minus the current power that the house currently needs, available to the EVSEs in the correct phase. Such a meter has the role "consumption" in the Charging Manager.
In this way, you can save yourself an increase in the house connection power and the associated upgrade costs and construction cost subsidies in many cases.
Meters for large currents:
For currents up to approx. 80-100 A you can use direct-measuring meters. Here, the phases are passed through the meter. For this, the meter must be designed to withstand the currents permanently.
In large houses, higher currents occur, so it is easier to run the phases through so-called meter transformers. These are coils in which a current is induced when current flows on the lines of the individual phases. The transformer meter can then measure this induced current. There are even models that are particularly small because they then do not have to have large terminals (1-2 division units).
In apartment buildings, you can also install such transformer meters in the "sealed" area in the meter cabinets or in a NH distributor in consultation with the energy supplier. This is easier than many people think! Such meters with measuring coils are called transformer meters.
If you operate a solar power system (PV) or a CHP unit and make the generated power available to the EVSEs, you can configure a generation meter in the cFos Charging Manager. Either install an external meter or use the inverter(s) of your solar system as the meter. The cFos Charging Manager then calculates the charging power available to the EVSEs as above (for meters for domestic consumption), while additionally adding the current generation power to the EVSEs. You should set such meters in the Charging Manager with the role "Generation".
If you have meters for consumption (and generation), you do not necessarily need meters for the EVSE, because the cFos Charging Manager assumes (see above) that the EVSE will always take the power offered to them.
Instead of installing meters for domestic consumption (and for generation), you can also install a central meter directly at the house connection point. If there is a generation plant in your house, this meter must be bidirectional! It then has the role of "grid reference".
The cFos Charging Manager then calculates the household consumption by subtracting the EVSE consumption from the value measured with this grid reference meter. To do this, you need either a meter in all EVSEs or a total meter for all EVSEs ("E-car consumption" role). Without a EVSE meter, the household consumption would otherwise be potentially underestimated.
Meter for the solar surplus:
The easiest way to measure the solar surplus is to use a bidirectional(!) grid reference meter (see above) and meter(s) for all wallboxes. You can then configure a charging rule for surplus charging in the cFos Charging Manager. Alternatively, you can also install consumption and generation meters (often the inverter of your solar system). For more information, see PV Surplus Charging (Solar Surplus Charging).
The cFos Charging Manager offers the following "virtual" meters:
You can additionally set these up to have an overview of these values.