|reply to flibby3655 |
Re: Upgrade/Replace Electric Panel
While all that is true in most cases, it's not enough to address "most cases" when working at kilovolt levels. People get killed when there are simultaneous unexpected problems.
Say your house is the only load at the end of a distribution spur. The fuse upstream of a fault blows, leaving your house connected to the spur, but without a connection to the rest of the distribution circuit. You've got your generator backfeeding the panel with the main off, but you've been turning the main on every so often to see if the utility's come back. This most recent time you checked was in the middle of the night, and being groggy you forgot to turn it back off.
Line crew rolls in later that night, sees the fault, looks over at your house, sees no lights on, and in a hurry the lineman just reaches over to pull the fallen branch that's causing the fault off the line. Boom, lineman's dead.
They're *supposed* to ground the circuit, the insulating gloves are never *supposed* to have holes in them, the pole grounding conductores are *supposed* to not have been stolen by thieves, etc. etc. etc.
Most recent outage I had at work, the crew was working on the 13.6 kV lines feeding our building without grounding them out or using their gloves. They were depending on our ATS working properly to keep them alive.