The SITOP PSE200U selectivity module distributes the load current to several 24 V feeders and reliably monitors them for overloads and short circuits. Short-term current peaks, e.g. due to high inrush current, are allowed by the electronics; branches with longer overloads are de-energized. This is ensured even on high-impedance lines and with "creeping" short-circuits.
short circuits. In these cases, miniature circuit breakers do not trip or trip too late, even if the power supply unit could supply the required tripping current. The SITOP extension module continues to supply the intact feeders with 24 V without any interruption or reaction and thus avoids a total failure of the system.