Don’t touch downed power lines? Nuts. (scratches item off To Do list). So much for that new hobby.
When I was a kid I had a friend whose father had no arms. He was a Safety guy at SC Electric and Gas. He taught safety classes. One day, he had been working in a cherry picker on a line, and for a reason he cannot understand, he took his gloves off and grabbed the line. Was not thinking. He had a mechanical claw on his right arm stub, but nothing on the left. Took them off at the shoulder.
It made a profound impact on me for safety consciousness.
The reason that a van de graf generator or just plain static from your clothes isn’t very harmful is that the electrical discharge is very high in frequency (which means it tends to travel along the surface instead of deep inside you) and very short in duration. A shock from a power line is much lower in frequency and has a lot more current behind it.
Electricity basically has two ways of killing you. The first is that it can interrupt your heartbeat. If someone is standing next to you with a portable defib then they can knock it back into a normal heartbeat, otherwise you’re in serious trouble. The funny thing about your heartbeat is that it is fairly sensitive to getting thrown out of whack at 60 Hz. This is why shocks where the current goes across your chest are particularly hazerdous.
The second way electricity kills you is that it can cook you. One of the old science experiments that I’ve seen a lot of people use to demonstrate this is to stick a nail in either end of a hot dog, and attach regular 120 volt house current across the nails. The hot dog is nicely cooked in a fairly short amount of time. The electric chair and power lines are fatal mostly because of cooking rather than relying on screwing up your heartbeat. If a 120 volt line will cook a hot dog in 15 to 30 seconds, imagine what a 5,000 volt line can do to you in a fairly short amount of time.
Also keep in mind that higher voltages can arc farther than lower voltages. If the voltage is high enough the electricity can jump from the line to you long before you touch the wire.
By the way, in case anyone attempts to reproduce the old hot dog trick, people in the electrical business tend to call a power cord with exposed ends like that a “suicide cord” and for good reason. Be careful.
Depends on what you mean by “lots of amps.” The total power through a transformer has to stay the same (you can’t defy physics, and a transformer doesn’t create energy). So, if you house is using 20 amps at 120 volts, it will be a mere 2 amps off of a 1200 volt line or 0.2 amps off of a 12 kV line. However, it’s not just your current that’s on the main distribution lines, but the current to every house in your neighborhood, the neighborhood down the road a few miles, and whatever else is fed by that main line. The total current capability of the wire depends on the thickness of the wire they use, but I’d expect it to be able to carry a few hundred amps with no problem.
By the way, the reason the voltages are pumped up so much is that the losses in the line are proportional to the current squared multiplied by the resistance of the wire, and as in the above example 0.2 squared is a much smaller number than 20 squared.
precisely
at 100,000 volts at 1000 amps, powerlines cant use insulation because it would be too heavy and too thick to string out over the hundreds of miles. Thats why they put it way up there so no ordinary fool can get to it. (the special fools will always find the way)
Another factor is that transmitting that much power produces a static charge which tends to arc over any insulation that you might use. Men who work with these powerline always make sure they are properly grounded before even coming near those things.
as a safety advice, at 100,000 volts with 1000 amps, theres really no such thing as insulation.
semi-related story:
A couple days ago, we lost all our power for a few hours–putting a serious cramp in the plans of people who were cooking for christmas dinner–because the top 30’ section of a pine tree had snapped off in some high wind and lay resting across the power lines (4200V x three) just in front of my office. Although the tree top was still suspended some 20’ in the air, it immediately caught fire and burned for the next couple of hours until the utility service arrived to take it down.
It was a pretty impressive display.
Not only don’t touch it. If you are close to it, don’t even point at it. If you get the chance, watch the History channel film on high voltage power lines.
The modern method of working on them is to do it from an insulated bucket, or put someone on the lines from a helicopter.
Since the bucket or the 'copter are at a different voltage from the line, even if not grounded, those voltages must be equalized before the lineman can touch the line to work on it. So when the bucket is about 6 to 8 ft. away, a long conductive probe that is connected to the bucket reaches out toward the line to clamp on. When it gets in the vicinity of a foot away from the line a spark as thick as the man’s forearm jumps between line and probe before the clamp is applied to the line to make a firm connection.