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I have nightmares about the buzzing on the pines when we get within ten feet of them.Remember a bucket worker hanging over the side of the bucket dead from being shocked many years ago in the pines at big bear.........
be carefull it happens quick and without mercy...robdog
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Thanks for the insight. Very well thought out post. If I may ask, what is your background or job title? It sounds like you have had extensive training in electrical awareness. Are you a lineman? Or line-clearance arborist?
Not really a matter. What you say makes sense. I have one question in my mind though. Is there a difference in potential when talking about resistance? Can potential be stepped up if wet, greasy or dirty?
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As for my credentials to mutter, I was a union A card electrician for 41 years and just received a retirement gift of a big-[use a better word] knife from Local 134. In my time, I was certified in high voltage cable splicing, supervised about 70 men in building Sears Tower, and supervised the construction of the first 345KV switchyard in Chicago.
More importantly, I've survived a couple of serious encounters with dame electricity that can be informative here in addition to the excellent references already provided.
1) It was a little past 4:30 on Friday and I wanted to finish splicing a new circuit in a box in a ceiling at a downtown office building in Chicago. I was standing on the next-to-the-top step of an aluminum ladder, had pushed myself well inside the false ceiling and was trying to join the new wire onto a twisted splice that was hot. I had to hold the spliced wires by their insulation with my right hand, and twist the bare ends with linesman's pliers in my left hand.
Not being left-handed was awkward, and I accidentally touched the energized pliers to my right thumb and created a current path from that hand through my arms and chest, and out the back of my left hand to a ceiling support wire.
I don't remember any pain, but my arms were vibrating and I couldn't let go of the pliers or the wires. I distinctly remember thinking, "This is how I'm going to die", and was very clear mentally about what was going on. I couldn't breathe, I couldn't even squeak, and there was no question that I was suffocating. A drunken Irish carpenter was singing in the next room, and I thought of the irony of how much louder he was than me, and I couldn't get his attention.
I was far enough in the ceiling to pass out and perhaps stay in the same circumstances at the risk of dying, so I concentrated on moving my feet back on the ladder step. I was surprised at how long it seemed to take, but I finally fell out of the ceiling with ceiling tiles and the ladder scattered around me.
The noise caused carpenter Clarence to stick his head in the room and chuckle at the sight. He didn't know what happened and didn't care. I sat there for a while and finally went home.
I learned a number of lessons in that ceiling and would always predispose myself later to fall out of danger when working on anything hot. I would only use my right hand and sometimes stand with my weight on one foot, so I could fall in a direction I wanted if I got in trouble.
I always checked my electrical tester every morning and did fire that bozo for telling a kid that his body could be used to tell if something was energized.
This was an example of enough current flow through my hands and arms that prevented them from releasing their grip and letting me get away. My body didn’t care what I thought or wanted. The circuit was 120 volts and the relevance here includes the hidden details of electricity nearby, you being comfortably nestled in place, and then getting tangled in some "low voltage" energized circuit.
2) In earlier incident, the only job available to my low seniority was doing HV cable splicing for a temporary power rerouting of the tower at the O'Hare airport. No one would take the job and I was too naive to be suspicious. Turned out that the HV cable pulled from manhole to manhole were all too short. Usually, everyone adds a few feet in the process of measuring and cutting, but the cable is expensive and this time it was exact—and too short.
Being naïve sometimes has advantages, and I planned to make a splice, strengthen it independently, and then pull the slack I could get out of each section to give me enough cable for the next splice. The contractor would have gone under if he tried to replace the runs, so he stayed away until I was done.
The splices were 5KV and because of the critical nature of power for the control tower, the tests were performed at 15KV by an outside company. When the technician shouted into the manhole that everything was fine, I reached to disconnect the clips and was suddenly bouncing around the manhole like a frog in a bowl making high-pitched noises.
Being naïve also has disadvantages, and I forgot to discharge the testing voltage that was stored in nearly a mile of cable. If I had been in a bucket, I would have popped out like toast from a toaster. High voltages can sometimes throw you free, but you’re also looking a few magnitudes of the forces that can kill you easily.
I’ll give one last incident because I’m back at writing again and it’s a good war story. It also fits the concerns and comments in this thread:
3) Friday, 4:30 in the afternoon, and three foremen are gathered around a panel in the switchgear room of a new downtown building in Chicago. Ron was trying to insert a 600v fuse in the clips of the panel and started to pound on the fuse with his linesman’s pliers. Right behind him, I shouted, “No!” and raised my hand to stop him. His pliers rolled from the clip and hit the steel back of the panel. The panel section vaporized and we were flung against the switchgear behind us with our silhouettes still there in the spatters of molten copper.
We were all blind from the flash and I didn’t know what would blow next because all the gear enclosures were open, so I started to drag the most injured guy, Ron, out of the room and down the stairs. I went back for Rod, the other foreman and we waited at the bottom of the stairs for help. The whole building had gone down, which was not supposed to happen, and it took some time to find us in the dark.
When flashlights finally showed up, I could see enough to cut the buried watch out of Ron’s swollen wrist and send an apprentice to get ice from the bar across the street. He returned saying they wouldn’t give him any, and I sent three men back with him to explain that we would indeed be getting ice.
My raised hand saved my eyes, and luckily, the copper in their eyes missed their corneas, but they had bad burns and were off for a short time. Ron seemed just as stupid and irresponsible when he returned, and I wondered if there was any lesson was for him on that afternoon. It didn’t matter. The job was finishing up and we all went our own ways with our own memories.
There are obvious lessons here:
Fridays and approaching quitting times are distractions in the pressures about leaving the job. Finishing in a hurry, with or without electricity, put us at risk and generally, we remember that. However, as stated by others in this thread, electricity lurks in hidden circumstances and is easily overlooked when we rush..
In the first incident, I was paralyzed from "only" 120v, but could still figure a way out of that disaster. How very smart of me. Change the circumstances ever so slightly, however, and instead of being smart, I’d just be memories for my family.
In the second incident, I was not a conscious participant in anything. My body was flung around in a violent response that ended only when it chose. Me? I now prefer something more self-controlled in my dancing near the edges of my life.
In my war story, it’s an illustration of the raw power of electricity. The fuses that shut down the building were filled with sand that turned to glass to stop the attempted infinite current flow. They did their job, but it was stupidity that started them working..
Likely no one here will be exposed to this staggering power, but the dangers are still present on a smaller scale. I’m not exactly frightened of electricity and fancy I learned as best I could. However in each incident, I wasn’t as smart as I thought, and I would have assured everyone that I knew what I was doing.
I don’t like the shield of ignorance and I don’t like arrogance of dogma. Each is an easy substitute for knowledge, real honest knowledge that can keep us safe because it is flexible and accommodate change.
As to the ever present, “It’s not the voltage, but the current that kills ya.” Clichés and platitudes aren’t ever any insulation against electricity. (I'll write later on this.)
Knowledge sometimes is—and sometimes might be. The rest of it is a crap shoot if we don’t take the time to learn, remember, and think a bit…
wulkowicz
