The DSE331 Automatic Transfer Switch Control Module monitors the voltage and frequency of an incoming AC supply from two different sources. These sources can be generator or mains (utility), or a combination of both.
The control module monitors Source 1 (S1) and Source 2(S2). When a failure occurs a start command is issued to the inactive source to take over the load. The module will return the load to the mains (utility) as soon as this becomes available.