From: alvarez@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@best.com