For my thesis I’m working in the lab in the Institute for High Voltage Engineering where I am researching on a self-blast circuit-breaker, trying to measure the voltage drop within the arc during switching.
A self-blast circuit-breaker needs a pressurized insulating gas to quench the arc. Therefore the CB that we use is installed in a vessel. From the vessel the air is evacuated and then it is filled with insulating gas – either SF6 or CO2. Because it is very dark in this vessel, I switched the light of my mobile on and put it inside the vessel, connected the breaker, checked the connections, checked again and then closed the vessel.
Well, the phone was still inside. I evacuated (10 mbar), put in the CO2 (4 bar) loaded the test circuit and gave the breaker some 5 kAmps (peak).
Measurement went well, data is safely stored, labmate comes in talking on his mobile, I think, hang on, where’ s my mobile? and the thruth dawns on me…I rush inside the lab (not forgetting to check for safety) open the vessel and … there it is, the light still on.
Good lord, I thank thee for salvaging the stupid ass’s mobile. And I never ever again want to feel like I felt in the moment I realized what I had done…