On Wed, Aug 25, 2021 at 2:34 PM <b...@theworld.com> wrote: > > Ok, I'll be the curmudgeon... > > Is this really a problem in practice? > > Most people I've known who worked around electrical mains etc assumed > the worst at all times and it isn't all that difficult to protect > against as one works. > > I realize one can infinitely invoke "better safe than sorry!", "an > ounce of prevention...!" > > <OBLIGATORY FUNNY STORY>
> Except maybe that one guy at Harvard who came to replace what turned > out to be a 100+ year old, home made, "breaker" which fed our machine > room which was hidden in a narrow dark hallway winding around our > machine room behind an unmarked metal, locked doorway. I had no idea > it existed but we had no power so I called for help. > > It was just a single copper bar about the size of a small candy bar > tensioned into hot clips. Probably 400A but who remembers. > > He removed the old one confidently enough, grabbed the new one with > rubber-handled pliers and gloves and... > > Him: Have you ever played football? > > Me: Actually, yes, I have, why? > > Him: If something doesn't look right when I put this thing in just > tackle me clear of it as hard and as fast as you can. > > Me: Um, ok. > > It all worked out fine and I wrote a memo that maybe Harvard could > spring for a proper $500 breaker box? > > </OBLIGATORY FUNNY STORY> > > ... and my "funny" story. We used to live in San Jose. There was a large heat-wave, and much of SJC lost power because of A/C load, etc. Anyway, my wife and I go and camp in one of the office conference rooms for a few days because the office still has power and A/C. Eventually PG&E claims that power is back on our street, so we drive back to San Jose and... no power. I flag down a passing PG&E truck and ask if they know when it will *really* be back. Lineman says that it is. I say it isn't. He says it is. I say it isn't. He gets annoyed, opens up the pedestal box and sticks a meter in it, and agrees that I have no power. He then sticks the meter across the 800A fuse, and discovers that the fuse blew. "Ah. I can fix that fer you..." he says, and goes to the back of the truck... "Doh. I'm out of 800A fuses. Um.... er.... well, here is a 6,000A fuse, that'll do..." I briefly question the logic of this (presumably the lines in the ground are sized somewhere around 800-1,200A), but he says that this'll do, and he'll come back in the next few days to replace it. I lived there for another 8 or so months, and it was never replaced, but, well,... not my wires, so, um ¯\_(ツ)_/¯ I guess... W > -- > -Barry Shein > > Software Tool & Die | b...@theworld.com | > http://www.TheWorld.com > Purveyors to the Trade | Voice: +1 617-STD-WRLD | 800-THE-WRLD > The World: Since 1989 | A Public Information Utility | *oo* > -- The computing scientist’s main challenge is not to get confused by the complexities of his own making. -- E. W. Dijkstra
