[Info-vax] OT: the Daily WTF for today is a VAX/VMS story

[Scott Dorsey]

From: alvarez at best.com (Richard Alvarez)
Newsgroups: alt.folklore.science
Subject: electrical phase reversal
Date: 1 Apr 1997 03:38:26 GMT

                                             1997 April 1  (almost)

Disclaimer:  The story that you are about to read, is true; only the facts 
have been changed, to protect me.  Any similarity between this story and 
what actually happened, is purely coincidental.  

   At a remote mountain facility, we generate our own electric power.  We 
generate 480 Volts, 3 phase, and distribute it to the various buildings.  We 
just had received our largest engine-generator set, 100 KVA capacity, back 
from overhaul.  Apparently the installer crossed the wires between the 
generator and the automatic load transfer switch, so the phase sequence was 
reversed.

   Our big generator had arrived just in time; early the next morning, the 
smaller generators couldn't handle the load, so the automatic load transfer 
switch started the big engine and put the 100 KVA generator on-line.  

   At one outside corner of the generator house, is an array of big 
industrial 3-phase flood-lights which illuminate the surrounding area.  With 
the phase sequence reversed, the flood-lights absorbed all the ambient 
light, so we couldn't even see the generator house.

   As the sun rose higher in the trees, the flood-lights absorbed so much 
light power that the generator drove the engine, and the engine produced 
Diesel fuel rather than consumed it.  The fuel level began rising in the 
tanks, which already were almost full.  Since we couldn't even see our way 
to the generator house to shut off the flood-lights or the generator, we put 
50-gallon drums under the tank filler-pipe, and caught the over-flow.  (The 
fuel tanks were far enough from the generator house, to be out of range of 
the flood-lights.)

   Since a wide area around the generator house was completely dark, the 
problem was to find the generator house, and shut off the flood lights.  I 
figured that in the darkness, I could crawl along the ground, then feel my 
way along the building wall to the door, go inside, and feel my way to the 
light switches on the wall.  So I put new batteries in a flash-light, tied a 
rope around my waist for safety, and had my associates hold the rope while I 
crawled into the darkness, holding the flash-light very close to the ground.  
In the dust that I was stirring up, I could see the flash-light beam bend 
upward toward the flood-lighs before the beam even hit the ground.  The 
flood-lights were pulling so hard on the flash-light that I barely could 
hold it.  But that was a blessing in disguise; all I had to do was follow 
the flash-light like a beacon toward the flood-lights at the corner of the 
building, and from there I should be able to find the door easily.  But the 
flood-lights pulled so much light from my flash-light, that they quickly 
drained the batteries, and then I had no more beacon.  Reluctantly, I turned 
around, and followed the rope back to the edge of the darkness.  We would 
have to think of another way to find the generator house.

   Meanwhile, the sun was rising higher in the sky.  Eventually, the sun 
cleared the tops of the trees, and a patch of direct sun-light hit the bank 
of flood-lights.  Then they absorbed so much light that they tripped their 
circuit-breaker, and thus disconnected themselves.  With the flood-lights 
de-energized, the cloud of darkness slowly disspiated, and at last we could 
see the generator house.  

   But inside the building, the lights still were operating, and they 
absorbed all of the outside light that went in through the open door-way.  
So from the door-way, I felt along the building inside wall to the light 
switches, shut them off, and went back outside while we waited for the 
engine cooling-fan to blow the darkness out of the building.  

   Eventually, with all the lights off, enough day-light went into the 
generator house through the open door-way, so that I could see to shut down 
the engine.  Then we reversed two of the 480-Volt wires at their terminals 
in the automatic load-transfer switch, and the electric power was back to 
normal.

   Later, we filtered the over-flowed Diesel fuel that we had caught in the 
50-gallon drums, and used it to heat the swimming pool through the whole 
winter.

   Now we are careful to check the phase sequence after electrical repairs, 
before we turn on our 3-phase flood-lights.

   There still are a few pockets of residual darkness around the generator 
house, to remind us of the time that we didn't check.

                                       Dick Alvarez
                                       alvarez at best.com






-- 
"C'est un Nagra. C'est suisse, et tres, tres precis."