Residual current circuit breakers B type Ex9LB63 are suitable for domestic as well as industrial applications, where are used frequency inveters, PV plant, EV chargers and similar elements. B type provides a sensitivity to residual AC, pulsating and smooth DC current, together with high frequencies up to 1 kHz.
They are based on electronic technology, which brings advantages of more accurate measuring of residual current and, as a consequence, reduction of unwanted tripping. These devices also do not suffer with magnetization of the tripping unit. Thus, there is no mandatory testing period, but they must be tested regularly. On this testing period local law or regulations may apply. Recommend is to test it every 6 months in fair enviroment and every month in heavy condition.