Hello Ramu,
On prima facie, as the current requirement is high with high DC output, it would be good to have two power supplies internally.
You may use LM723C for voltage regulation.
It’s a linear regulator and you may need heat sink.
Use an auxilliary power supply (derived from the main AC in) for powering up LM723C.
Faults can be detected using simple high input impedence comparator circuits.