The Power pack is used as a power source for VCB panels in substations where station battery supply is not available. Power Pack stores the energy in backup Capacitor from line connected PT and that stored energy can be used to Trip / Close the Circuit breakers when AC Input is not available.
There are total two outputs. One output is for stored energy and other is for non-stored. Stored output can be used when AC input is not available. Non-Stored output will be available as long as AC input is present.