> > In theory, Jay is correct, but assuming that theory will always work in > practice is, in this case, how linemen end up dead. We're all well aware of > never assuming theory = practice, but admittedly the stakes tend to be a > little lower in our world. >
right. my grandpa was a high-voltage/wattage engineer. He always said, `an engineer can make an error, but only once'. Luckily, we can make many errors :) -- Amir Herzberg Comcast professor of Security Innovations, Computer Science and Engineering, University of Connecticut Homepage: https://sites.google.com/site/amirherzberg/home `Applied Introduction to Cryptography' textbook and lectures: https://sites.google.com/site/amirherzberg/applied-crypto-textbook <https://sites.google.com/site/amirherzberg/applied-crypto-textbook> On Wed, Aug 25, 2021 at 1:55 PM Matt Erculiani <merculi...@gmail.com> wrote: > In theory, Jay is correct, but assuming that theory will always work in > practice is, in this case, how linemen end up dead. We're all well aware of > never assuming theory = practice, but admittedly the stakes tend to be a > little lower in our world. > > Ensuring that a generator physically cannot backfeed is just one layer of > protection against the already very high risk of the job of a lineman. Then > there is, of course, checking for the presence of voltage before starting > work, but it's possible for a generator to start AFTER this check. > > Another layer of protection is grounding all conductors prior to beginning > work, so that if power does come back (via the grid or a backfeed) A: The > lineman and bucket is not the best path to ground and B: The source is > tripped. > > Reading through that forum post, it sounds like that particular contractor > had a reputation for lacking proper safety precautions, so one or more > safety layers may have been removed, making the risk/impact of any single > mistake much greater than it should be. > > -Matt > > On Wed, Aug 25, 2021 at 11:25 AM Mel Beckman <m...@beckman.org> wrote: > >> Jay, >> >> No, because transformers work in both directions :) >> >> Plus, to the previous commenter that talked about “suicide cords”: >> they’’re more correctly termed “homicide cords”: >> >> “ The lineman killed yesterday was working for Pike Electric and picked >> up a line that was connected to someones house that hooked up a generator >> and did not disconnect from the distribution system. The linemans name was >> Ronnie Adams, age unknown. He had two children and a wife. As far as I know >> he was from Louisiana. They are trying to set up a fund for his family, but >> nothing I have heard of yet. I will let yall know more as I hear of it. I >> wish they would really teach folks the proper connection of generators, >> this was a really tragic and preventable accident. Stay Safe and think >> about it before you do it.” >> >> https://powerlineman.com/lforum/showthread.php?711-Storm-Death >> >> -mel >> >> On Aug 25, 2021, at 10:12 AM, Jay Hennigan <j...@west.net> wrote: >> >> On 8/25/21 07:04, Mark Tinka wrote: >> >> On 8/25/21 15:59, Ethan O'Toole wrote: >> >> >> How would this not load the generator or inverter into oblivion? >> >> Not sure I understand your question. Say again, please. >> >> >> If you fail to isolate your generator from the incoming utility feed so >> that you're back-feeding the utility and the power is out for your >> neighborhood or the whole city, would not the load of trying to light up >> the whole town completely overwhelm your little generator to the point that >> it fails, stalls, or trips its own output breaker? >> >> -- >> Jay Hennigan - j...@west.net >> Network Engineering - CCIE #7880 >> 503 897-8550 - WB6RDV >> >> > > -- > Matt Erculiani > ERCUL-ARIN >
