Reminder: Never connect a generator to home wiring without transfer switch

Warren Kumari warren at
Wed Aug 25 19:09:26 UTC 2021

On Wed, Aug 25, 2021 at 2:34 PM <bzs at> 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...!"

> 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?
... 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...


> --
>         -Barry Shein
> Software Tool & Die    | bzs at             |
> 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
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <>

More information about the NANOG mailing list