Electricity

 

 

 

From: Oxsan
Date: 24 Mar 2003
Time: 12:45:43

Electricity in both a practical and a theoretical sense has been a big factor in my life as long as I can remember. When I was a very small child my father was a telephone construction superintendent, later when I was 10 to 14 he was a construction superintendent for various contractors building Rural Electrification Lines, even later after he had been nearly killed by cross-phasing 12, 000 volts due to a helpers stupidity he became a residential and commercial wiring contractor and Master Electrician (what linemen used to contemptuously call a “Narrowback”’) He got rich at this business and made himself even richer in real estate speculation. So my childhood was immersed in things and talk electrical.

At eighteen I left home after one year of college and entered the Navy where for some long forgotten reason I wanted to become a meteorologist. The Navy specialty selection board at boot camp turned this down contemptuously and stamped my papers “Eddy Program” which meant that I was to receive a year’s instruction in electronics and ultra high Frequency techniques (then a new thing) and emerge as an electronic technicians mate---and that is what happened except that I hornswoggled my way into the aviation branch of the Eddy program and became an Aircraft Electronic Technicians Mate (AETM). So my introduction to a life dependent upon electricity and its quirks was via the Navy. For the next thirty years or more in American industry my associates assumed I was an electrical engineer and I did not try to correct that impression. I was not an imposter because my application and records showed that I was not an engineer but I successfully parlayed that Navy training into a very fine job and 37 years of very successful and lucrative management experience.

Let me tell you now about some of the types of electrical experiences I have had or observed based largely on differences in form and strength of the electricity.

Static Electricity

Static electricity is funny stuff. It is funny peculiar not necessarily funny ha-ha. My first introduction to static was when Dad was up on a telephone pole about ten miles from Brownfield, Texas splicing a wire. He had one end of the telephone wire under his right arm and had inserted this short end into a device called a “sleeve” and reached out and grabbed the other end of the wire and was putting it in the sleeve and opening up his two pair of “connectors” (too complex to explain). I was eight years old and had come out on this non-school day with Dad while he did this trouble shooting. I was sitting in the Model A rumble seat about twenty feet below him. It was a weird kind of weather. Black clouds were rolling in from the west and it was obviously about to rain yet the gusty wind was kicking up huge amounts of dust and sand off the plowed field nearby and visibility was even getting bad. I looked back toward Lubbock and suddenly saw a huge ball of fire moving down that wire toward my Dad not too rapidly. I opened my mouth to yell at him but before I could form a word that ball of fire hit him in the right armpit from the rear. Dad as was his custom was wearing a safety belt but not using it. He just wrapped one leg around the pole to steady him so he could use both hands to work. The ball of fire knocked him completely off the pole and he landed moaning in the plowed field. When I got to him his shirt was burned to a char under his right arm and he was groggy and he looked like he had second-degree burns over an area around his arm and shoulder. .I helped him up and got him back over the fence and into the car. I took off his hooks and tool and safety belt. He said he could drive, and we drove back to Brownfield.

Dad always spoke of this as the time he was struck by lightning but I was convinced that this was not the case as I learned more about electricity later. This was static electricity I think and it must have been a whopping charge of it because static will not usually cause any damage, if the entry point and exit points have no gaps. In a few days Dad was OK. In fact he went back the next day and finished splicing that wire. He then decided that a bottle of Ten High would be therapeutic.

During the two years I taught general science and physics the demonstrations of static electricity were always favorites with the kids. We had a simple Van de Graf generator and it always woke the class up when I had one kid turning the generator and reached out with the carbon rod provided and drew about a six to nine inch arc off the generator. I didn’t feel a thing. We always were able to find someone in the class with hair dry enough to stand on end when the static was passing all over them. Then I got to tell them all about Nickolai Tesla and his feuds with Thomas Edison and George Westinghouse and how Tesla used to give parties at Manhattan night clubs trying to use static electricity to sell the virtues of AC over Edison’s DC. There was a bit of cheating there because static is not AC but it was impressive.

Magnetos

I guess that every farm boy has talked his cousin or best friend into pissing on the terminals of a pulse type farm tractor generator. I had been conned into doing it once to “cool off the terminals”. It is a shock you won’t believe. Also when I wasn’t at the farm I could always find an old Kellogg phone with a magneto ringer in it and make an electric chair to “execute” the kid that we decided needed it the most. These two uses of the magneto may account for the low birthrate on the High Plains of Texas. It got me into bad bad trouble with a few concerned mothers—including my own.

110 Volt /220 Volt/440 Volt

The most common of all voltages in the US and is responsible for the most deaths by electrocution. That is a freaky statistic however because the only reason it is true is that it is the voltage that most people come in contact with. The worst I was ever hurt by 110 volts was when I was drilling a hole in a steel pipe set as a post in wet ground with an electric hand drill. The drill shorted out, I was wet with sweat, I had my free hand on the post when the drill shorted and we had a merry time for a minute or two. Dad used to routinely stick his finger up in a light socket to see if it was hot---I would use a tester. I learned all the mysteries of the electrical code, how to balance circuits and how to wire houses and light commercial buildings from Dad. I learned how to use a hickey (a tool for bending conduit) and all of the tricks of the electrician’s trade. Dad taught me the first rule of working 110, 220 and, 440 “Hot”, that is with power on. The secret to it is to “keep one hand in your pocket”. With good rubber soled shoes on s dry non-metallic surface and light gloves on you can safely work up to 440Volts with little danger. An experienced electrician working 440 hot will brush the back if his hand against the source before touching it with the front of his hand because 440 Volts and 2300 Volts are probably the worst voltages about causing a reflex closing of the hand around the bare wire or bus bar. A 220volt circuit of three wires is actually one 110volts above ground and one 110volts below ground so the only time you actually work a potential of 220Volts is when you work two particular wires of the three-wire circuit

B+

When I first started out in electronics the most common voltage encountered in an electronic instrument was 400 volts applied to the plates of electronic tubes. This voltage for reasons I have forgotten was always referred to as B+ power. It would sting you pretty hard but there was a marvelous thing about most receivers and transmitters of the WWII era. They had poorly regulated power supplies. The “regulation” of a power supply is an expression of the ability of a power supply to maintain a voltage output with increases in load. For example if your lights dim when your air conditioner kicks in that is an example of poor regulation. Your transformer out on the pole may be near capacity or you may have poor distribution in your master switch box. So if you put your hand on the plate of some of the electronic equipment it would overload the power supply and wouldn’t hurt but just a minute. On B25 aircraft during WWII the standard Very High Frequency (VHF) transceiver was a British piece of equipment called the SCR 522. This little jewel was mounted on the top of the bomb bay so the cover over the innards of the equipment could only barely be opened when the equipment was installed in the airplane and the technician who put it in could not see in it at all. Every time you installed one of these little gems in the airplane which I did on 68 aircraft in the blistering hot summer of 1950 it was necessary for the technician (me) to lie down in a puddle of my sweat on the aluminum bomb bay top and reach my right hand blindly into the top of the equipment to adjust the final amplifier plate circuit to match the impedance of the antenna which was signified by a dip in plate current I was reading on a meter held in my left hand. Two things you must understand to know why this was such an onerous task: The B+ voltage on the SCR 522 is provided by an alternator. Alternators have outstanding regulation. If you put a heavy load on an alternator it doesn’t care. It doesn’t quit. It just keeps jarring the hell out of you. The second thing is that this is not 60-cycle AC like your house it is 400 cycle, 400 volts which is the combination of frequency and voltage most likely to cause you to scream. Then to top it off the Limey engineers put a bare B+ test probe right beside the final amplifier adjustment knob. I hit it on all 68 aircraft.

When I was working on radar (then so secret we could not pronounce the word in public) I always wore my metal dog tags hanging down my back instead of in front, because one time my dog tags swung down into the equipment and right into the horns of the Magnetron and burned a neat little trail right across the nape of my neck. Not a good place to take it.

12000Volts/66000 Volts/138000 Volts

These are the three most common distribution voltages these days and I have never worked any of the three and don’t intend to at this late date. Both 12000 and 66000 will “come to meet you” as the distribution linemen say. I have seen Dad work 12000 with rubber gloves only but I notice that today’s linemen normally use what the linemen call a “hotstick” to work these two voltages. A hotstick is about a six or eight foot long wooden pole with sort of a robotic hand on the end of it. It is rare to see 138000 on anything other than steel towers and I doubt seriously if 66000 or 138000 are ever worked hot. All three of these voltages do have a tendency however to knock you away from the voltage source rather than freeze you to it. I don’t ever remember hearing about anyone who got into 66000 or 138000 but surely some one has somewhere some time. Dad was pulled into 12000 once and it took him about a year to get back to work.

So much for electricity. It is great stuff.