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How to prepare your house for charging electric vehicles?

One of the biggest advantages of an electric vehicle is the convenience connected with its everyday use. You simply move a filling station into your own garage. Previous experience shows that up to 80% of all recharging is done at home. But in that case, an ordinary 230V socket is not enough. Connecting your electric vehicle to an ordinary socket for several hours may cause fire in your garage due to the increased temperature and, moreover, the charging power of the socket is very low. Recharging an economical electric vehicle for eight hours over the night provides you with a driving distance of some 100 kilometres, with less economical vehicles it is just about 60 kilometres.
An ideal solution is a home wall mount charging station fitted with an electronic control system, which is usually connected to the three-phase grid and can provide charging power of up to 22 kW. You just pull out the permanently attached charging cable and connect it to your car. Fast DC charging stations are not suitable for home recharging as they are expensive and difficult to install. Moreover, frequent fast charging is not good for batteries in electric vehicles.

The prices of home charging stations range between 800 and 1200 Euros, and their installation and the compulsory installation audits cost about the same. Reasonable home charging requires three-phase connection, a residual current device type A or B (for simpler devices) and a sufficient circuit breaker. The capacity of the main circuit breaker has to be higher than the rating of the charging station. While most family houses have three-phase connection, the input power determined by the capacity of the main circuit breaker may not be sufficient. Even if the breaker capacity was just enough for charging an electric vehicle, there would not be much left for other appliances at home. Charging an electric vehicle with a running washing machine or a dishwasher could cause the fuses to blow. Therefore we recommend that you consult it with a specialist and have the main circuit breaker capacity increased. You have to send an application for increasing the main circuit breaker capacity to the distribution network operator. Apart from the approval from the network operator, it is also connected with a lump sum fee and higher regular distribution rate payments.

The most advantageous solution may be a smaller increase in breaker capacity and the installation of the HomeGuard system that provides the charging station user with dynamic power control. The system monitors the current consumption of the house and all the appliances, and allocates the remaining current up to the main circuit breaker capacity to the charging station for charging your electric vehicle. The charging power changes dynamically according to the current situation and the electric circuit does not get overloaded. Therefore it saves the costs connected with increasing the circuit breaker capacity. An easier option may be to set a permanent limit to the charging current or to install a priority relay. But this will “blow” the charger completely and stop the charging of the vehicle. Naturally, neither of these options is an ideal solution.
Practically, there are no limits to the place of installation. The charging station should be installed in the place you are going to park your car and in the height where it is easy to use and you can comfortably walk past. There is no limit to the distance from the main circuit breaker. However, the further it is, the bigger cross section may be required for the supply cable. But in case of ordinary family house installation, it is rarely a long distance. Although our charging stations are water and sunlight resistant, the ideal place of installation is inside a covered parking space or a garage.

Apart from its convenience, the main advantage of home charging is its price. As an electric car owner you are entitled to get convenient distribution rates. Charging at low rates is about half cheaper compared to high rates. That is why we recommend that you install the DMS module (demand-side management) that will enable you to switch on charging just at low rate times.

Of course, apart from family houses, charging stations can also be installed in the garages or parking spaces of apartment houses. However, the whole process is a bit more complicated, as the installation of charging stations has to be discussed and approved by the co-owners of the building, and you need to have the required charging power calculated and discuss increasing the maximum input power for your apartment house with the distribution network operator. Even in this case the main circuit breaker capacity may not be enough to cover the power demand of all charging stations operating at full capacity at the same time. The solution is again the HomeGuard system installed right next to the main circuit breaker dynamically adjusting the output of active charging stations between each other as well as according to the current consumption of the entire apartment house. This eliminates the risk of switching on all appliances at the same time causing a “blackout” of the whole apartment house. The HomeGuard system can easily control up to 16 charging stations and the total input power of 200A or 138kW. This solution also includes chip card authorization enabling verification of electric vehicle owners and optionally accurate recordings of consumed electricity.