a)switch on the storage system with

a)switch on the storage system with AC voltage respectively less than 85% and greater than 110% of the nominal value Vn (while the frequency must be between 49.90 Hz and 50.10 Hz), and check that the unit prevents the parallel with the grid, no power supply/consumption according to network analyser reading.b)After at least 30 s from the time of start of the test referred to in point a), check the persistence of the state "open", i.e. absence of output power supply / consumption. At this point bring the voltage within the limits 85% Vn and 110% Vn and simultaneously disable the storage system. In these conditions then proceed to reset, while checking that the parallel with the network and the starting of the power supply/consumption does not take place before at least 30 s from the time the storage system is enabled.c)At this point it is necessary to simulate with the storage system in operation a disconnection due to the voltage being respectively higher and lower than overvoltage and undervoltage thresholds, in order to verify that, when voltage is restored within the expected range 85 % Vn and 110 % Vn, the time before reconnection is at least 300 s.d)Repeat the test described in a) with voltage 85 % Vn and 110 % Vn and frequency respectively less than 49.90 Hz and greater than 50.10 Hz, checking that the unit prevents the parallel with the network, no power supply / consumption according to network analyzer readings.e)After at least 30 s from the time of start of the test referred to in paragraph d) check the persistence of the state "open", i.e. the absence of consumption / supply output power. At this point bring frequency f within the limits - 49.9 Hz and 50.10 Hz and simultaneously disable the storage system. In these conditions, then proceed to test, while checking that the parallel with the network and the start of the power consumption / supply does not take place before at least 30 s from the activation of the storage system.f)As for point c), it is necessary to simulate with the storage system in operation a disconnection due to the frequency being higher and lower respectively than overfrequency and underfrequency thresholds, in order to verify that, when frequency is restored within the expected range 49.9 Hz and 50.1 Hz, the time before reconnection is at least 300 s.