You will NEVER see a bird land on an energized transmission line 69KV or greater

[Landon Caeli]

A bird's foot is connected to a bunch of non conducting, porous, non static charge acquiring feathers .. there is no circuit formed to anything having a lower potential. No appreciable current will flow.

The human being in the following video of a 7.65KV line, (see from 2:00 min mark onwards), is physically and electrically attached to a helicopter, (or a hollow flying sphere). That sphere is able to disperse any acquired charge immediately back to the air flowing over its conductive rotor blade skin .. that is, it, along with he human, becomes a conducting element in a circuit and current therefore flows. The human is also not killed as he approaches the wire (ie: as he penetrates the strong surrounding field) .. for the same reason a bird doesn't.

That is an outrageous claim. The line is clearly dead and grounded, because in order to do that operation energized requires "barehanding" which means he would need to be wearing a full-body metal mesh suit. What he's doing is bonding onto dead wire between grounds, which has a static charge build-up on it.

Also, they would never energize the line after pulling in that brand new wire, without installing the spacers beforehand.

 

[SelfSim]

It could very well be they can "see" it or perhaps they are able to "feel" the fields before they reach a dangerous level. Like sharks can feel/sense their prey.

They would probably feel/hear the acoustic vibrations set up in the air surrounding the conductors .. birds have pretty quick sound/touch response reflexes. Some birds are brave .. and even attack when their threat instinct is aroused, so they are capable of responding in ways we wouldn't necessarily expect, also.
Our expectations about electricity however have been pounded into us since birth, so there's no real reason to think birds would necessarily perceive a threat .. (nor is there a necessary one).

 

[Landon Caeli]

If the conductor on a 500KV line was so imperfect as to force a current to flow between a bird's legs, it wouldn't be much good for long haul transmission purposes, eh?

As anyone who understands science would tell you, conductors force nothing. The electricity goes wherever it want's, the conductor only provides a path for it.

...But electricity will take *every* path it possibly can.

 

[Landon Caeli]

...Really, you guys should be paying me for this class.

 

[SelfSim]

That is an outrageous claim. The line is clearly dead and grounded, because in order to do that operation energized requires "barehanding" which means he would need to be wearing a full-body metal mesh suit.

I think he's already donned the suit there(?) (Which is beside the point, anyway).

What he's doing is bonding onto dead wire between grounds, which has a static charge build-up on it.

Ahh .. so now you're finally starting to invoke a static induction mechanism in your explanation! (Seems like we're progressing a little then).
Why do you say the helicopter is at ground? What direction do you think the current is flowing in? Ie: from the helicopter to the wire, or vice versa?

Also, they would never energize the line after pulling in that brand new wire, without installing the spacers beforehand.

Its not a 500KV line, but this one clearly states they are bonding onto a 230KV live line (see/hear what it says at the 0:47min mark).

(Also says the resistance of the line is 8-12 micro ohms over what looks to be about a 3(?)metre span?)

 

[sjastro]

Are you ready for the giant hole to get shot through your argument...?? Here it is:

Birds are NOT a dielectric material..!

...They have "blood" running throughout their bodies, that consist of minerals including iron and copper... Conductive minerals..!

...Yes it's true... Animals are in fact, highly conductive, just like the dirty water in your bathtub is highly conductive, which is why we have GFCI outlets in the bathroom, in case your hair dryer falls in there, it doesn't kill you. In the same way as bathwater, blood is conductive, therfore birds are conductive.

Why not bring the kitchen sink into the discussion along with the dirty bathwater, CFCI outlets and hairdryers as it has as much relevance.
You clearly don’t understand what happens when electrocution occurs when a bird contacts two wires.
First there is dielectric breakdown of skin or feathers at higher voltages.

In the case of human skin;

The characteristics of the skin are non-linear however. If the voltage is above 450–600 V, then dielectric breakdown of the skin occurs.[16] The protection offered by the skin is lowered by perspiration, and this is accelerated if electricity causes muscles to contract above the let-go threshold for a sustained period of time.[10]

Then there are the burns caused when the current passes through the bird as a resistor not a conductor where electrical energy is converted into heat energy.
The resistor cannot dissipate heat as rapidly as the production of heat energy resulting in burns.
Animals are not highly conductive; human skin has a resistance between 1000-100,000 ohms, by comparison a highly conductive material such a copper is 0.017 ohms.

 

[SelfSim]

...Really, you guys should be paying me for this class.

(.. and demanding a full refund following it) ..

 

[sjastro]

...Guys, unlike what @sjastro has said, birds are *highly* conductive, just like people are, due to the minerals in our liquid-filled bodies...

The physics explanation was clearly beyond your level of comprehension so you had to engage in cherry picking and you couldn't even get that right as explained in my previous post.

 

[SelfSim]

As anyone who understands science would tell you, conductors force nothing. The electricity goes wherever it want's, the conductor only provides a path for it.

As anyone who understands Circuit Theory, (which is based on Kirchoff's Laws), resistive elements from nodes, divert current flows via less resistive path endpoints at that node.

 

[sjastro]

As anyone who understands Circuit Theory, (which is based on Kirchoff's Laws), resistive elements from nodes, divert current flows via less resistive path endpoints at that node.

Spoken like a true electrical engineer.....
BTW on the subject of electrocutions have you heard this one.

A chemist, a biologist and an electrical engineer were on death row waiting to go in the electric chair.

The chemist was brought forward first. "Do you have anything you want to say?" asked the executioner, strapping him in. "No," replied the chemist. The executioner flicked the switch and nothing happened. Under this particular State's law, if an execution attempt fails, the prisoner is to be released, so the chemist was released.

Then the biologist was brought forward. "Do you have anything you want to say?" "No, just get on with it." The executioner flicked the switch, and again nothing happened, so the biologist was released.

Then the electrical engineer was brought forward. "Do you have anything you want to say?" asked the executioner. "Yes," replied the engineer. "If you swap the red and the blue wires over, you might make this thing work."

 

[SelfSim]

"If you swap the red and the blue wires over, you might make this thing work."

It wasn't wired according to standard (colour coded) wiring conventions? That's a bit hard to swallow ..

 

[prodromos]

It wasn't wired according to standard (colour coded) wiring conventions? That's a bit hard to swallow ..

Who's wiring conventions? We had a Swedish guy working with us on a job where we were installing new 3-phase circuits in a switchboard. I twice had to remind him that Australian colors are not the same as European. He had wired the Neutral to an Active phase and one of the Active phases to the Neutral (AUS/NZ standard Red/White/Blue are phase colors, Black is Neutral. European standard Brown/Black/Red are phases, Light Blue is Neutral. Earth is Green-Yellow in both)

 

[Landon Caeli]

As anyone who understands Circuit Theory, (which is based on Kirchoff's Laws), resistive elements from nodes, divert current flows via less resistive path endpoints at that node.

@SelfSim, and @sjastro please answer this:
Do you think I, as a Lineman, can go up in an insulated bucket, with a totally insulated fiberglass boom, 100% isolated from ground, and be able to touch a 33KV line with my bare fingertip and feel nothing..?

<DISCLAIMER> (I am in no way ever going to do this, but hypothetically, I want to see what you think)

 

[Landon Caeli]

Who's wiring conventions? We had a Swedish guy working with us on a job where we were installing new 3-phase circuits in a switchboard. I twice had to remind him that Australian colors are not the same as European. He had wired the Neutral to an Active phase and one of the Active phases to the Neutral (AUS/NZ standard Red/White/Blue are phase colors, Black is Neutral. European standard Brown/Black/Red are phases, Light Blue is Neutral. Earth is Green-Yellow in both)

What color would you use for your wild leg..? We customarily always make that one the red one.

 

[SelfSim]

@SelfSim, and @sjastro please answer this:
Do you think I, as a Lineman, can go up in an insulated bucket, with a totally insulated fiberglass boom, 100% isolated from ground, and be able to touch a 33KV line with my bare fingertip and feel nothing..?

No .. because a lineman in a bucket, supported by a fibreglass boom attached to a truck, is not the same as a bird flying in from dry air ..

 

[Landon Caeli]

No .. because a lineman in a bucket, supported by a fibreglass boom attached to a truck, is not the same as a bird flying in from dry air ..

Why not? The boom has been dielectrically tested with 100,000 volts, and is totally clean.

 

[SelfSim]

Why not? The boom has been dielectrically tested with 100,000 volts, and is totally clean.

'Totally clean' and '100% isolated' are meaningless concepts.

 

[Landon Caeli]

'Totally clean' and '100% isolated' are meaningless concepts.

Wow. Who knew!?

 

[sjastro]

As anyone who understands Circuit Theory, (which is based on Kirchoff's Laws), resistive elements from nodes, divert current flows via less resistive path endpoints at that node.

This sounds like the stray current problem which effected the automotive industry in the late 20th century.
When I worked in the automotive industry a worldwide technological change occurred by replacing copper radiators with aluminum.
The automotive industry largely underestimated the significance of stray currents in the electrical system passing through the radiator coolant.
Copper radiators were resistant to stray current corrosion but aluminum could be destroyed within months.
Stray current became a universal problem with automotive manufacturers.

I recalled being dragged to Japan having to explain to my Japanese masters (Toyota) how we had solved a particular type of stray current corrosion that effected the coolant outlet spigot on the engine when their own design engineers failed.
In this case the corrosion was due to a cell reaction between the spigot and the radiator hose clip and there was a cooperate effort between Toyota Australia and an American radiator hose supplier.
The solution was to use a very high resistance hose well above the Toyota spec range.

Rather than receiving a pat on the back for a job well done I was accused of embarrassing their engineering staff who felt they lost face by keeping them out of the loop and most importantly for dealing with an American hose supplier and not a Japanese supplier.

 

[SelfSim]

Wow. Who knew!?

Doesn't help your case along though ..