A team (Supervisor & Technician) entered the BMF LV panel Area for continuity test with No Permit Job (NPJ). As per NPJ team has to work on conduit fixing and light fixtures. Site Supervisor and the technician opened the LV panel for checking continuity and decided to power up the lighting circuit which is not included in the NPJ. To power up the lighting circuits, the technician switched on 32A ELCB in the same panel without checking for confirmation of its respective outgoing cables. The moment he turned on the 32A ELCB the electrical flash over occurred.