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Why NOT to touch power lines.

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ItsASecretDummy

Jan 1, 1970
0
Just how stupid can someone be to be walking un top of a train bare footed
and reach up and touch a high voltage power line?


We used to cook hot dogs that way back when AC power was cheap.

Also, he would have had a problem even with a lower voltage. The only
reason one can call it high voltage is because the electrical power
industry (err... the NEC) has defined "high voltage" as starting at like
600 Volts. Other standards place it at 1000 Volts.

That train was likely fed by a 400 Volt line. Not high voltage, but
you can bet that the "resistor" that a person poses to that line to
ground isn't high enough to keep the person from frying like a 1973 hot
dog in a tray on pins plugged into the wall.

Not high voltage. Certainly high enough though. The idiot was free from
it, and he touched it a second time.

Reminds me of Dilbert's manager.
 
R

Rheilly Phoull

Jan 1, 1970
0
ItsASecretDummy said:
We used to cook hot dogs that way back when AC power was cheap.

Also, he would have had a problem even with a lower voltage. The only
reason one can call it high voltage is because the electrical power
industry (err... the NEC) has defined "high voltage" as starting at like
600 Volts. Other standards place it at 1000 Volts.

That train was likely fed by a 400 Volt line. Not high voltage, but
you can bet that the "resistor" that a person poses to that line to
ground isn't high enough to keep the person from frying like a 1973 hot
dog in a tray on pins plugged into the wall.

Not high voltage. Certainly high enough though. The idiot was free from
it, and he touched it a second time.

Reminds me of Dilbert's manager.

I doubt that would only be 400v, much more likely 4digit power.

Rheilly P
 
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ItsASecretDummy

Jan 1, 1970
0
I doubt that would only be 400v, much more likely 4digit power.

Rheilly P

The trolley and the other electric trains in the US are at 400V to my
knowledge.

Keeping arcing down is one reason. Watts are watts. The motors do not
need "4digit power". It is far safer that way, especially in wet areas.
The lines are not that far above the trains. Sheesh. The trains are
made by Siemens.

The train in the picture in India must be a local, 1.5kV DC. There was
one arc, then a body roast arc, then a body roast fire. He was dead
faster than any electric chair ever made.

That was not your little 1.5 kV photo flash source, which makes a snap
as it sends a single 1/10 second arc through you, if that.

That was POWER behind that 1.5kV. It remained at 1.5kV, and was a very
low value resistor for a few seconds.

Unbelievable! I am surprised that a broadcast or cable news service
didn't pick it up. (not the video, the mention of it).
 
I

ItsASecretDummy

Jan 1, 1970
0
From my student days, I still remember going to an AIEE lecture on
electrocution. The speaker claimed that there were few documented cases
of people dying from dc unless there was an inductive kick or actual
cooking involved.

Note that the person was very much so being cooked. One could see the
arc through his entire body.
I also remember, of reading in that great scientific
journal True magazine :=) of a broadcast tech getting hung up on a 20kV
power supply. He ended up getting thrown across the room but survived
with injury and aches.

He sure would have backed Edison if the war of currents were still going
on.

A 20kV or even a 400kV power supply for a friggin transmitter has no
balls whatsoever compared to a high amperage DC feed for powering a
train.

Most DC supplies are current limited against dead shorts as well.

A DC fed train gets orders of magnitude more available current AT
voltage than a simple supply for a transmitter is capable of providing.
 
A

Andrew Gabriel

Jan 1, 1970
0
We used to cook hot dogs that way back when AC power was cheap.

Also, he would have had a problem even with a lower voltage. The only
reason one can call it high voltage is because the electrical power
industry (err... the NEC) has defined "high voltage" as starting at like
600 Volts. Other standards place it at 1000 Volts.

That train was likely fed by a 400 Volt line. Not high voltage, but

Mostly, India is same as UK, i.e. 25kV on overhead rail pantographs.
 
I

ItsASecretDummy

Jan 1, 1970
0
Maybe I did not make myself clear. The point is that this dc source did
not kill. Ac sources with much less total energy can kill by starting
fibrillation.

If you are stupid enough to believe Edison's bullshit, you are more
ignorant of history than I thought. DC most certainly can kill, and it
ALSO can kill by way of causing a defibrillation of the heart. DC deaths
are not all attributable to the frying of flesh.

It is less likely, but absolutely possible to get a fibrillation event
from DC..
120VAC has often been deadly.

I can take two #16 bare solid wires at six inch strip, and grab the
bare ends while the other ends are plugged in. I can crawl up the wires
with my hands until the curl in my wrists can no longer take it.

Most deaths from such a low voltage are due to the element of fear.

If I am working on a chassis, and that same 120 VAC hits me
unknowingly, it will knock me across the room.

If I know it is there, I can touch it. I would not dare do this,
however, with 240 or a higher than 120 Volt source.


No let go current is rather
 
I

ItsASecretDummy

Jan 1, 1970
0
Mostly, India is same as UK, i.e. 25kV on overhead rail pantographs.


India's long inter-city runs are 25kV AC.

Their local runs are 1.5kV DC.

That guy got hit with DC from what I could see.
 
D

Don Kelly

Jan 1, 1970
0
ItsASecretDummy said:
India's long inter-city runs are 25kV AC.

Their local runs are 1.5kV DC.

That guy got hit with DC from what I could see.

Hard to tell.
I suspect AC- there were two distinct jolts with no arcing between and no
follow up arcing after the second jolt -when his hand was still near the
line- this is indicative of AC rather than DC. I also suspect that the
line was cleared by a recloser and then re-energized, cleared again and
locked out. Again, more typically AC practice. He deliberately touched the
line once- he was dead before the second touch or near touch. I also
suspect 25KV as most lines outside the Mumbai area appear to be 25KV AC -
and one source indicated that this was supposed to be converted by 2002.

Don Kelly
[email protected]
remove the x to reply
 
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ItsASecretDummy

Jan 1, 1970
0
Hard to tell.
I suspect AC- there were two distinct jolts with no arcing between and no
follow up arcing after the second jolt -when his hand was still near the
line- this is indicative of AC rather than DC.

That is silly. The time gap was huge. Several hundredths of seconds
easily. I saw two distinct pops. an AC "flash" is usually blue, and the
AC cycles are the reason. The DC POP arc is usually the same color as
what it practically instantly vaporizes at the entry/exit site. AC also
causes reverberatory spasm responses. He stood there while the current
fried the resistor.
I also suspect that the
line was cleared by a recloser and then re-energized,

I doubt that seriously, considering the instantaneous currents required
by trains on the track. It was far more able to completely fry him and
not even wince at the loading.
cleared again and
locked out.

It isn't a sub-station service feed.
Again, more typically AC practice.

But that is not what happened.
He deliberately touched the
line once- he was dead before the second touch or near touch.

It was 1.5kV DC. If it was their 25kV line, it would have arced to him
before he even got to it, and would have continued to arc as he pulled
away. It was clearly DC, and it was clearly low enough voltage that the
arc remained below a couple inches, as the video demonstrates to the
trained eye. Had it been AC, he would have had an arc as he pulled away
the first time.

Again, there will be no breakers opening with a load as "small" as a
human on this type of feed. His entire incident used far less juice than
a train does as it pulls out from a platform. And the immediacy of the
event wouldn't "trip" anything either. A person on the wire will get
continuously fried. A BAR across the feed *would* trip an interruptor.

That guy fried so fast, the power source thought an engineer farted.
Nothing more. A train represents a far lower resistance load. The "slew
rate" by which his "event" made the current go up likely wouldn't cause
more than a yawn, much less a trip.
I also
suspect 25KV as most lines outside the Mumbai area appear to be 25KV AC -
and one source indicated that this was supposed to be converted by 2002.


As I stated before, I read the discussions, and it was stated earlier
by a guy claiming to be there (India, not the station) that they use 25kV
for the long inter-city runs, and 1.5kV for the short run trains, which
is a different rail system. Not interconnected. Replacing all those
trains would be quite expensive.

I think it was the DC set from the video. Ac would have arced to him
before he got to it. Also, a big platform, there would have been no way
they would have let him up onto the train. In the smaller system, it
would be easier.

It is just conjecture by both of us though. We both observed the same
thing, and have both described plausible event chain theories.

We should ask the "slumdog up in smoke" if such excitement leads to
orgasm. We could ask David too. Oh, wait a minute! It's too late to
ask either one! :) Now, we'll never know.
 
I

ItsASecretDummy

Jan 1, 1970
0
My question here is, what was the outcome of the guy lying dead on top of
the train after the incident? Did they leave him there to slide off later
when the train went rolling down the tracks throughthe country side?
Noticed all the public audiance ran when they saw him arc, what did they do
after the final flash.... stand there and stare at the dead body?

Please REFRAIN from top posting in Usenet. This is not your email
client.

They obviously waited until he was no longer burning, or they dowsed
him, and then pulled him down. Very unlikely that they moved the train
with him up there. The train was likely already dormant as a result of
his presence.
 
I

ItsASecretDummy

Jan 1, 1970
0
You remember correctly, it was the Presto Hot Dogger.
http://www.gpopc.com/catalog/item/5313687/5766786.htm

Yep. We had one, and one of my mom and dad's friends had one.

They had a lid that actuated an interlock switch.

I always thought they were a little exposed, but defeating the interlock
was not easy to do. IIRC, it was pre-polarized plug days, ala early to
mid seventies.
 
I

ItsASecretDummy

Jan 1, 1970
0
The presto shows five cooking at once. At 8 amps each that
would be 40 amps total. I need to cook another one on the
nails and look at that current again.

Bwuahahahaha!I thought it looked a bit high.
I have a clamp on now
maybe I can put it over the dog and see if that matches the
ampmeter on my variac.


hahahaha! It would yield a readings it is conducting and exhibiting a
field.
 
A

Archimedes' Lever

Jan 1, 1970
0
There's a video on youtube whose title claims it's 25kV AC.

So what? There are other posts of it elsewhere that have folks that are
from India discussing it. They refer to two different systems being in
use.
A second video says it's 26kV but was removed.

None of it is at 26kV.
I also saw the video elsewhere with better sound and heard a 50 Hz buzz.

I heard no buzz at all, and I had one where all the platform folks'
dialogs were clear. I heard a pop. No buzzing or humming.
 
A

Archimedes' Lever

Jan 1, 1970
0
I listened to it again, and it's not the quality of the recording, it was
the fact I was using headphones the first time, but using my laptop's
speakers the other times. I just listened to the video again with the
headphones and there's a definite 100 Hz (not 50 Hz like I wrote) hum/buzz
with headphones, kind of like plucking a string, but without them it just
sounds like a pop.

These are el-cheapo headphones, too. It's actually a cool sound, other
than the fact someone died making it.


The hall of souls was glad to have it back, since it appeared that he
didn't want it any more.
 
D

Don Kelly

Jan 1, 1970
0
ItsASecretDummy said:
That is silly. The time gap was huge. Several hundredths of seconds
easily. I saw two distinct pops. an AC "flash" is usually blue, and the
AC cycles are the reason. The DC POP arc is usually the same color as
what it practically instantly vaporizes at the entry/exit site. AC also
causes reverberatory spasm responses. He stood there while the current
fried the resistor.
------
Several hundreths of seconds or possibly 30-60 cycles. no big deal. Colour
of arc depends on the material and temperature involved. AC flashes, even
at light current are not necessarily blue- I have seen many that aren't.
Streamer flashover as an insulator starts to break down is generally
bluish but once a solid arc is established, it is yellow. Blue for
ionization but yellow for follow current in a plasma.
Reverbatory spasm results-why? 100-120Hz pulses- the body won't spasm at
that rate-particularly above "let-go" .
-------------
I doubt that seriously, considering the instantaneous currents required
by trains on the track. It was far more able to completely fry him and
not even wince at the loading.
----------
Possibly -it was a conjecture- neither of us know. However, I have known of
a case where a person in contact with a line did cause tripping and repeated
reclosure. He ended up on the ground with the wire on top of him (7200V) The
interval between reclosures was longer and the current was not enough to
kill him or render him unconcious but did do terrible damage. Rubber boots
burnt through at the ankles, holes in his back -he lived as a basket case.
All due to a combination of drunken bravado and stupidity.
The reclosure conjecture came about from the dead time betweeen pops.
-----
It isn't a sub-station service feed.
-------
True but this doesn't mean that some kind of recloser system isn't in use.
Again no information
------------------------
But that is not what happened.


It was 1.5kV DC. If it was their 25kV line, it would have arced to him
before he even got to it, and would have continued to arc as he pulled
away. It was clearly DC, and it was clearly low enough voltage that the
arc remained below a couple inches, as the video demonstrates to the
trained eye. Had it been AC, he would have had an arc as he pulled away
the first time.
-------
His hand was not far enough away between the pops for a 1.5KV arc to
extinguish. I have pulled arcs of 1/2 to 1 inch at 5-10A at 120V. where AC
simply produces a minor spark at the same voltage and current. The current
would have been far less than that but DC arcs are recalcritant . Yes, 25KV
would have arced to him but it is not possible to see if there was a pre-arc
but it was possible to see that it was out momentarily
---------------
Again, there will be no breakers opening with a load as "small" as a
human on this type of feed. His entire incident used far less juice than
a train does as it pulls out from a platform. And the immediacy of the
event wouldn't "trip" anything either. A person on the wire will get
continuously fried. A BAR across the feed *would* trip an interruptor.
----------
Actually, I can't argue with that - which then points to AC.
-----------
That guy fried so fast, the power source thought an engineer farted.
Nothing more. A train represents a far lower resistance load. The "slew
rate" by which his "event" made the current go up likely wouldn't cause
more than a yawn, much less a trip.



As I stated before, I read the discussions, and it was stated earlier
by a guy claiming to be there (India, not the station) that they use 25kV
for the long inter-city runs, and 1.5kV for the short run trains, which
is a different rail system. Not interconnected. Replacing all those
trains would be quite expensive.
-------
And the last of the 1.5KV DC was supposed to be phased out about 7 years
ago.
----------------
I think it was the DC set from the video. Ac would have arced to him
before he got to it. Also, a big platform, there would have been no way
they would have let him up onto the train. In the smaller system, it
would be easier.
------------
Questionable - the video doesn't give the detail well enough to say. As for
a big platform - please note the station building in the background
It is just conjecture by both of us though. We both observed the same
thing, and have both described plausible event chain theories.

Agreed- we don't have any information as to where and when, nor, in
particular the actual voltage involved.
So we can both conjecture and blow smoke.
 
D

Don Kelly

Jan 1, 1970
0
ItsASecretDummy said:
Yep. We had one, and one of my mom and dad's friends had one.

They had a lid that actuated an interlock switch.

I always thought they were a little exposed, but defeating the interlock
was not easy to do. IIRC, it was pre-polarized plug days, ala early to
mid seventies.

A favourite demonstration by the local utility consisted of grounding
(through a limiting resistor) one end of a hot dog on a "hot stick" and
touching a 2300V line with the other end. "See, Kids, don't go after your
kites- call us"
 
A

Andrew Gabriel

Jan 1, 1970
0
Agreed- we don't have any information as to where and when, nor, in

Mahananda Express at Etawah in Uttar Pradesh, May 29, 2009 (or
maybe a day or two beforehand - that might be the reporting date).
 
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