In household a properly designed electrical diagram should also include overvoltage protection. This overvoltage protection saves complete household against over voltage, which comes from the grid, when thunderstorm or something similar is in the nearby and causes voltage peaks. This household (external) overvoltage cuts the peak in more levels ( Class I, Class II, Class III) of the overvoltage and ensures that voltage in household grid stays in normal value. This overvoltage protection must be installed on all phases. See some instructions about that topic on site:
httphttps://www.tsipower.com/sites/uploadsdefault/files/white-papers/WP-IEC-61312-Surge-Protective-Device-Coordination-2012-06-14.pdf
Residual current protection and over current protection do not protect your household against over voltage.
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Class D same as Class III or Type 3 (protections in devices, in our case - varistors)
What could go wrong?
If the station is connected incorrectly, it will damage several variators.
There are two scenarios of overvoltage: interphase or earthing overvoltage.
If one or the other happens, it will damage one varistor. If both happen at the same time multiple varistors.
When this happens, it can also damage cables and connectors!
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IMPORTANT: always check the connection (in electrical cabinet and in charging station) before the first start-up.