Extreme Jobs - High Voltage Power Line Inspection
Why Electrical Engineering Stack Exchange recommends it
Electronics Stack Exchange answerers and commenters link it as a vivid real-world example of capacitive coupling, floating potentials and why a Faraday suit lets someone touch a live line without being shocked.
Recommended by 2 people across 2 different months, 2018 to 2023.
What it is
A short World Channel clip from the 'Extreme Jobs' series showing linemen inspecting energised high-voltage power lines. A worker in a metal-mesh Faraday suit is carried by helicopter to the line and crawls along the live conductor, using a wand to equalise potential first.
What people said
Recommends user201365 · 2018-10 · Electrical Engineering Stack Exchange · on “Wouldn't Charge Flow On Power Lines Due to Capacitance”
Yes, very much so, for an excellent visuals, see: [this video] and [LINK] Note that these linemen are wearing Faraday (metal mesh) suits.
Recommends crasic · 2022-02 · Electrical Engineering Stack Exchange · on “Why does AC pass through my body if I touch a hot wire? Is there a closed circuit created?”
This video of high voltage maintenance has been shared here before [this video] high voltage electricity lines are inspected while powered. While being 100 feet in the air adequately prevents a short circuit to the earth, capacitative coupling of the helicopter requires an equalization wand to bring the helicopter (and the person) to line voltage. The inspectors themselves are wearing fireproof suits built in a fashion to function as faraday cage for any other stray fields around the high voltage conductors. Worth a watch.
Cites SalahTheGoat · 2020-09 · Electrical Engineering Stack Exchange · on “Can you get shocked if you touch a hot wire whilst perfectly electrically insulated?”
Okay this issue has been bothering me immensely so hopefully someone will be able to help me out or steer me in the right direction. Lets say hypothetically I possessed an absolutely perfectly insulating chair and I stood on it and then touched the hot wire of a three prong socket, would I get shocked? My existing knowledge tells me that I will get 'somewhat' of a shock. This will be because a human body has a non-zero capacitance and so charge will flow onto and off me sequentially in sync with the frequency of the mains supply as it oscillates my potential up and down with the wire that I am presumed to be touching. The question of whether this oscillating current into and out of my body a
Cites hacktastical · 2021-01 · Electrical Engineering Stack Exchange · on “Professor said no current flows to ground”
In your example, the battery and resistors are floating as a separate circuit, except for the single tie to ground at one point between the two resistors. Because there is only that one ground tie, no loop to ground is formed, so no current flows into or out of ground. It’s the ‘loop’ part - or lack thereof - that your professor forgot to tell you about. Anyway, the question is only interested in current . Because of this, we also know we can ignore the ground tie (no loop, so no current flows to or from it). It's a red herring. This in mind, we can conclude that the only current flowing in the circuit is the loop formed by the battery and 2 resistors . Kirchhoff's Current Law tells us that
Cites Solomon Slow · 2022-06 · Electrical Engineering Stack Exchange · on “High voltage three phase power lines and ground danger”
@explogx, You mean, like in an academic journal? No. But have a look at this video [this video] . It shows a lineman climbing onto a high voltage line from a hovering helicopter. At 1:05 in the video, He reaches out with a probe to electrically connect the helicopter to the line. It draws an arc, half a meter long. That's current flowing between the _completely isolated,_ hovering helo and the wire. Can you imagine him doing that with his hand instead of the probe? Also, see [LINK]
Cites hacktastical · 2023-11 · Electrical Engineering Stack Exchange · on “Why does current flow through my body if I touch a hot wire?”
This answer may shed some light on all this: Professor said no current flows to ground [LINK] Power lines are referenced to earth ground, and so are you, assuming you're not wearing insulated shoes or are suspended in mid-air [this video] . The ground behaves like a huge, low-resistance wire between you and the power generator. If you're unlucky enough to touch the power line, you complete the path from generator, through the line, through you, then through ground back to the power generator. Because the voltage is so high, even with a resistive body and body-to-ground path enough current can flow to be painful, if not fatal. Now, why didn't your LED light when you connected it to the battery thr