The question of the week on racking in medium voltage breakers got me thinking about this video:

and what else could be done to prevent it from happening again. Yes, I know the guy was wearing insufficient PPE and should have had the door closed. I also know that in our newer gear where I work we have remote remote racking operators, fiber optic flash detection and tripping and the gear is designed differently to contain or re-direct an arcing fault.

All that said, I expect events like this mostly occur while racking the breakers in and out. What if there was a quick connect gas hose port in each cubicle with a nozzle inside to flood the stabs with SF6 or some other gas while racking? If there were a fault the gas should help knock it way down I would think and help to save the equipment even if you were using remote racking.

Maybe it already exists and I’m not aware or maybe it’s not feasible due to not being enclosed would keep you from achieving a high enough concentration of gas, or the EPA wouldn’t like it, or it would be too expensive. It is just a thought I had if there are any manufacturers reading this.

I also thought about compressed bottled gasses inside the gear with quick acting firing could possible serve a similar function but those would likely never fire fast enough and never be tested or maintained. READ MORE.