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Transmission lines have protection systems to protect themselves from lightning strikes, but in the case of a strike hitting a line under test - how is the user protected?

I'm looking for an answer in the scenarios of a strike hitting the line 20 miles from the engineer, and a strike hitting the line under test directly at the engineers location? - if there is a difference in these scenarios of course.

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    They don't climb towers during a storm. – Tony Stewart EE75 Apr 06 '18 at 20:11
  • Yes, of course. Freak strikes can occur, or for example a storm down the line unknown to the engineer. –  Apr 06 '18 at 20:13
  • Then they are not protected. – Eugene Sh. Apr 06 '18 at 20:15
  • https://en.wikipedia.org/wiki/Lightning_arrester .. https://www.youtube.com/watch?v=Zi4kXgDBFhw as you can see high voltage is harmless. – cm64 Apr 06 '18 at 20:20
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    You probably don't want to be touching both the wire and the tower at the same time, whether there's a lightning strike or not. – The Photon Apr 06 '18 at 20:26
  • nothing they do would be affected by lightning 20 miles away. – dandavis Apr 06 '18 at 20:36
  • @cm64 nice, safe from lighting and most of the RF in the 2 m band as a thin wire Faraday cage attenuates alot. but not enough for NEMP – Tony Stewart EE75 Apr 06 '18 at 20:38
  • I was hit by lightning 15 miles away in a metal boat. with a 100m Seismic cable in my hand. But no worse than neoprene shoes in a hotel with old Nylon carpet and 25kV – Tony Stewart EE75 Apr 06 '18 at 20:39
  • The Chinese have some of the biggest and higest voltage networks in the world. > 1GV http://www.euronews.com/2017/12/30/workers-make-final-checks-on-china-s-new-power-line – Tony Stewart EE75 Apr 06 '18 at 20:44
  • The magnetic field stored in a charged transformer is also high risk of discharge currents just like a high voltage cap or a battery returning to nominal V except coils continue to produce current from remanence and charged dielectric while discharging. 100 kVac arcing 2 meters from me didn't scare me or harm me but 100kVdc arcing behind me a floating wall girder 30 meters behind me made me curious. (but I figured it out) I love the Chinese Power Engineers as much as the Japanese Electronic Engineers I have worked with, for their skills. – Tony Stewart EE75 Apr 06 '18 at 20:56
  • I was taught that very long open lines are at danger from solar flares that can charge the capacity of the line and should not be contacted without discharging them first. Ground at both ends. – Optionparty Apr 07 '18 at 21:03

2 Answers2

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Maybe it is more safe on a transmission line tower than standing on earth because of the following reasons: 1) A standing person is higher above ground and is more likely to catch a lightning strike, whereas on the tower, the lightning will always hit the tower first. 2) A iron tower is a better conductor than earth, which leads to smaller voltage drop per distance at the same lightning strike current (U=R x I)

Stefan Wyss
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There is extensive training for safety which would fill a book.

1) Insulation. > 4 meter fiberglass rods for moving live lines with hook. Tools cleaned daily. Insulated Bucket truck lift. Safety arc flash gear. Double insulated boots etc .

2) Earth bonding mobile equipment

3) Overhead protection

According to the NOAA, over the last 20 years, the United States averaged 51 annual lightning strike fatalities, placing it in the second position, just behind floods for deadly weather. In the US, between 9% and 10% of those struck die, for an average of 40 to 50 deaths per year (28 in 2008).

Meanwhile USA has that many death by firearms every week.

Anecdotal

Last year I was at the Coral Castle in a rain storm in Florida, the lightning capital of North America , our guide was too afraid to take us outside. So I asked him, has there been any recent reports of power interruptions or worker deaths? He said No but still wouldn't go out. I said see those little antenna at the top of every wooden power line pole. Its an earthed tungsten sharp tip that acts like an antenna above the trees. That's why.

Some are coiled which slows down the current ionzation but reduces the induced voltage. The best are short sharp tungsten tips on top of every pole well bonded to earth to bypass the structure.

There are still risks and more details to cover, but this gives some idea.

We went out in an umbrella surrounded by the castle and much taller poles along the street closely spaced with lightning protection. Every city does not do this, but in Florida it works. They need it. enter image description here

Tony Stewart EE75
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