ELECTRICITY

There have been quite a few times when I have been humbled by my own sheer negligence...quite a few of those occurences have involved the mysterious fores of electricity. Getting thrown across a room by a 30,000 volt shock because i didn’t check to see if the neon work station I was disassembling was first diconnected....

All I got for that near death experience was a hearty round of applause and a “Welcome to the thirty thousand volt club!” cheer from the other employees/victims of the Neon Compay I was working for.

Years ago, I worked on an old railroad drawbridge that was powered by an ancient electric motor hooked into the old DC current lines from Toledo Edison. The switch that controled the speed of the motor was a big cranked series of curved copper slider plates that elegantly controlled the amount of current going to the motor.

The plates had to be perfectly smooth and were regularly serviced by the railroad  electricians who would coat them with vaseline to insure the smooth operation.

I worked the night shift, from 11pm to 7am and the bridge got a lot of use during those hours. When things went wrong, they usually picked those wee night hours...

A little burr of copper was all it took for the DC current to arc and the entire bridge house would light up flashing in the night like Frankensteins Lab...the bridge would get stuck in an awkward position and I would have to get the electricians out or there woud be no trains  or boats moving over or under the bridge.

The only electric shocks I have gotten lately have been from inadvertently touching the cow  lines around my property...once, I was picking up some debris and I didn’t realize they were on and I touched the line with my forehead...I believe I experienced a self administered blast of electro shock...I forgot what I had eaten for lunch a few hours before....

Today, it was a PER plastic water line popping a seal and spraying high pressure up in the ceiling of the basement, into a electrical connection box...

Everything shorted out...I turned off the water and fixed the seal...better than before, I hope, It had heald for the last 5 years...

 But I had to dry out the box and check it out good before I dared to turn on the current again. Luckily, I could get the circuits on the first floor going and I used a hair dryer to speed up the drying process......

Here is a video of a real nice electrical event, a Jacobs Ladder created by a 550 kv Switch opening...if you are interested, here is an explanation of what is going on...

    During normal operation, the switcher will first open the SF6 interrupters which disconnects the HV circuit so that the air break switches can open with no current flowing. Once the air break switches completely rotate to the "open" position, the SF6 interrupters then reclose. Normally, this sequence insures that the air break switches operate de-energized and arc free.

Instead, here, the air break switches opened while the current was still coming through.

    The arc stretches upward, driven by rising hot gases and writhing from small air currents and magnetic forces, until it easily exceeds 100 feet in length. As impressive as this huge arc may be, the air break switch was really NOT disconnecting a real load. This arc was "only" carrying the relatively low (about 100 amps) magnetizing current associated with the line reactor. The 94 mile long transmission line associated with the above circuit normally carries over 1,000 megawatts (MW) of power between Boulder City, Nevada (from the massive generators at Hoover Dam) to the Lugo substation near Los Angeles, California. A break under regular load conditions (~2,000 amps) would have created a MUCH hotter and extremely destructive arc. Imagine a fat, blindingly blue-white, 100 foot long welding arc that vaporizes the contacts on the air break switch and then works its way back along the feeders, melting and vaporizing them along the way. Still, you've got to admit that this "little" 33 MVAR arc is certainly an awesome sight!