Damaged Power Supply 400VAC/24VDC

[ChipTrick1]

A few days ago a damage was generated in a power supply with an input voltage to three phases (3x400V-500V) and a regulated output of 18vdc-29.5vdc.
It is currently connected to a safety switch that was activated at the time of damage to the source, but did not prevent it from being damaged.
Check the phase control and there were no errors in the load balancing and the protection fuses at the source outputs (connected to the loads) did not show any damage.
Is it possible that it has been damaged by a current spike in the power supply or internal damage from the source itself?
Attached schematic image and source model.

 

[HarryA1]

If you open the unit up and  find out what is wrong with it that will give you insight into what the problem is/was.

If the problem is on the AC input  side it may well be, as you say, a spike from the power source.