luke warmwater
Senior Member
Anybody watching this show tonight? It's on now and is about Electricity.
Modern Marvels on History Channel
- Thread starter luke warmwater
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luke warmwater
Senior Member
Re: Modern Marvels on History Channel
Well it's over.
I'm not sure if they ran this show before or not. It was actually on High Voltage.
Primarily Linemen history, and yes it had the famous helicopter part.
The beginning touched on Edison's D.C. system.
Some great old photos.
Original lineman death ratio was 1/2.
According to this show, a lineman would "get between the wires and send electricity to the ground."
Well it's over.
I'm not sure if they ran this show before or not. It was actually on High Voltage.
Primarily Linemen history, and yes it had the famous helicopter part.
The beginning touched on Edison's D.C. system.
Some great old photos.
Original lineman death ratio was 1/2.
According to this show, a lineman would "get between the wires and send electricity to the ground."
Re: Modern Marvels on History Channel
Yes, I enjoyed watching the linemen "barehand" the wires. I am somewhat confused about the "bonding on" part. You see the arc of current until they bond on. Where is the arc going (since it can't go to ground)? Is seems like the current must be going somewhere, and I don't understand why that doesn't shock anyone.
Steve
Yes, I enjoyed watching the linemen "barehand" the wires. I am somewhat confused about the "bonding on" part. You see the arc of current until they bond on. Where is the arc going (since it can't go to ground)? Is seems like the current must be going somewhere, and I don't understand why that doesn't shock anyone.
Steve
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: Modern Marvels on History Channel
Steve once you Bond on you are at the same potential that the wire is at. This is just like the birds sitting on a wire. When you go to bond on if the voltage is high enough the resistance of the air is high enough to cause a spark. This is more of a static discharge. as the line runs for miles and will build up a charge. it's even a bigger spark when bonding on from a helicopter as the rotor wash will drive it's own static charge.
It also depends on the area of what you are using as a static sink, as the larger the area, like a big plat form or bucket can increase the discharge to the bond stick.
Steve once you Bond on you are at the same potential that the wire is at. This is just like the birds sitting on a wire. When you go to bond on if the voltage is high enough the resistance of the air is high enough to cause a spark. This is more of a static discharge. as the line runs for miles and will build up a charge. it's even a bigger spark when bonding on from a helicopter as the rotor wash will drive it's own static charge.
It also depends on the area of what you are using as a static sink, as the larger the area, like a big plat form or bucket can increase the discharge to the bond stick.
caosesvida
Senior Member
Re: Modern Marvels on History Channel
hurk is the line a static charge or a capcitive charge? just curious
hurk is the line a static charge or a capcitive charge? just curious
luke warmwater
Senior Member
Re: Modern Marvels on History Channel
I watched it the second run also.
On at least 3 different occasions, the show said that electricity is trying to get to ground.
One was by a lineman fron Georgia Power. He stated that electricity will take the least resistive path to ground, be it a copper wire or a human body.
What are they teaching their lineman in Georgia???
People watch these shows and hear this and take it for truth.
I watched it the second run also.
On at least 3 different occasions, the show said that electricity is trying to get to ground.
One was by a lineman fron Georgia Power. He stated that electricity will take the least resistive path to ground, be it a copper wire or a human body.
What are they teaching their lineman in Georgia???
People watch these shows and hear this and take it for truth.
charlie
Senior Member
- Location
- Indianapolis
Re: Modern Marvels on History Channel
Todd, you are stuck in the low voltage applications. They are dealing with high voltage. I am guessing that the secondary of the transformers are indeed configured in a wye and only static lines are taken to cover the phase conductors. We know that the power is always trying to get back to the source which is the substation transformer. At that voltage, that path will be through the ground when a ground fault occurs.
Even medium voltage will work with the earth used for a fault current return path. Our distribution voltage is 13.2Y/7.62 kV, plug 7620 volts into ohms law.
The bottom line is, for line work, that electricity will take the least resistive path to ground, be it a copper wire or a human body.
Todd, you are stuck in the low voltage applications. They are dealing with high voltage. I am guessing that the secondary of the transformers are indeed configured in a wye and only static lines are taken to cover the phase conductors. We know that the power is always trying to get back to the source which is the substation transformer. At that voltage, that path will be through the ground when a ground fault occurs.
Even medium voltage will work with the earth used for a fault current return path. Our distribution voltage is 13.2Y/7.62 kV, plug 7620 volts into ohms law.
The bottom line is, for line work, that electricity will take the least resistive path to ground, be it a copper wire or a human body.
luke warmwater
Senior Member
Re: Modern Marvels on History Channel
Charlie,
thank-you, but I knew that You would correct me.
Charlie,
thank-you, but I knew that You would correct me.
luke warmwater
Senior Member
Re: Modern Marvels on History Channel
bennie, I'll check it out, thanx.
bennie, I'll check it out, thanx.
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: Modern Marvels on History Channel
Batch
They are the same phase we use to set the triangle spacers on lines like that. but we used a cart that would ride on the bottom two and we would pull our selves along by the top one seting the triangles behind us. these lines crossed the country and if I remember right were above a million volts. we had to be set down by helicopter. and the bond on stick was over 20' long. and when it got close it made a loud "POW" like a lightning strike. It took a few to get use to. Wind had to be less than 2 MPH and once in a while a gust of over 5 MPH would hit and you felt like you were on a roller coaster.
Batch
They are the same phase we use to set the triangle spacers on lines like that. but we used a cart that would ride on the bottom two and we would pull our selves along by the top one seting the triangles behind us. these lines crossed the country and if I remember right were above a million volts. we had to be set down by helicopter. and the bond on stick was over 20' long. and when it got close it made a loud "POW" like a lightning strike. It took a few to get use to. Wind had to be less than 2 MPH and once in a while a gust of over 5 MPH would hit and you felt like you were on a roller coaster.
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