Touch Voltage Radiation Shells Around A Light Pole, 2 Questions

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Traffic Control

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My question is regarding the ?shell? voltage radiating out from a light pole with no effective ground-fault current path. I am assuming that if there is a ground fault by the HOT wire in contact with the metal light pole outer edge, the fault current is trying to find it?s way back to the earth grounding rod at the closest service. I have two questions:

1) given a fault by the HOT wire on to the metal pole, could fault current find it?s way back to possibly 2 service locations?

2) If there is only 1 service location for the light pole, will the ?touch voltage? radiating out into the earth shell from a short by the HOT wire to the metal pole be symmetrical circles of voltage potential or will the ?touch voltage? be higher between the pole and the service, versus the other side of the pole (the side of the pole NOT between the pole and the service)? In other words, if an electrician was standing on the side of the light pole that is not between the service ground rod, would the ?touch voltage? be the same? Thanks!:?

Please feel free to correct and wording or technical terms. :D
 
Traffic Control said:
My question is regarding the ?shell? voltage radiating out from a light pole with no effective ground-fault current path. I am assuming that if there is a ground fault by the HOT wire in contact with the metal light pole outer edge, the fault current is trying to find it?s way back to the earth grounding rod at the closest service. I have two questions:

1) given a fault by the HOT wire on to the metal pole, could fault current find it?s way back to possibly 2 service locations?

2) If there is only 1 service location for the light pole, will the ?touch voltage? radiating out into the earth shell from a short by the HOT wire to the metal pole be symmetrical circles of voltage potential or will the ?touch voltage? be higher between the pole and the service, versus the other side of the pole (the side of the pole NOT between the pole and the service)? In other words, if an electrician was standing on the side of the light pole that is not between the service ground rod, would the ?touch voltage? be the same? Thanks!:?

Please feel free to correct and wording or technical terms. :D
Click to expand...

IMHO,

Question 1 I would say Yes... as long as both services are served by the same transformer...
Question 2. I would say symmetrical circles... once the pole is energized by a hot conductor, it becomes a hot conductor and a very large one. Is there any difference between the front and back side of a #12 conductor? :)
 
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xformer said:
IMHO,

Question 1 I would say Yes... as long as both services are served by the same transformer...
Question 2. I would say symmetrical circles... once the pole is energized by a hot conductor, it becomes a hot conductor and a very large one. Is there any difference between the front and back side of a #12 conductor? :)
Click to expand...
I see your point on the wire, but I can't help think that as you would move away from both the pole and the service ground that the voltage drop across the ground would get much less vs if you were to headed toward the service ground. The distances we are speaking of would be hundreds of times larger than a #12 wire. Also it's the ground we're talking about not 99.9% copper. :)..Thoughts?
 
1: Yes (See #3)
2: I'll see if I can make a graphic but based on others I have made I will say non-symmetric unless I get proof otherwise.
 
Non symmetric, certainly, but not one-sided either.
As long as you are well outside the 90% voltage drop zone of the remote electrode, there is little to bias the field around the pole in that direction.

Tapatalk!
 
mivey said:
1: Yes (See #3)
2: I'll see if I can make a graphic but based on others I have made I will say non-symmetric unless I get proof otherwise.
Click to expand...
Not symmetrical. The closer the pole and service the greater the influence but the surface voltage equipotential lines are closer together between the pole and service. Kinda "squished" between the two if you want a visualization.
 
mivey said:
Not symmetrical. The closer the pole and service the greater the influence but the surface voltage equipotential lines are closer together between the pole and service. Kinda "squished" between the two if you want a visualization.
Click to expand...

perhaps the word symmetrical is the wrong word... would concentric be better?
 
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