Kneejerk Bombas
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Can you line clearance guys, say these two lines (connected together on the insulator across from guy) are definately not hot?
Line clearance question
- Thread starter Kneejerk Bombas
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OTG BOSTON
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no one can
No one can say for sure from here. Why is it insulated if it is not hot??
No one can say for sure from here. Why is it insulated if it is not hot??
Kneejerk Bombas
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A couple years back I was sent to trim some trees and noticed there was a transmission line running through them, so I declined to climb and told the homeowner to call the electric company. They sent a guy out and he said the line was dead and they wouldn't do the trimming.
I went back and noticed the line terminated at an insullator but then followed it back to see it was running a whole street and was hot.
Now I'm sceptical.
These wires run out to an island, and they disconnect them during the winter because theres no emergency access to the island. The power company said the were not hot, but I can't follow them back to see. Does the fact that they are two lines twisted together mean anything?
I went back and noticed the line terminated at an insullator but then followed it back to see it was running a whole street and was hot.
Now I'm sceptical.
These wires run out to an island, and they disconnect them during the winter because theres no emergency access to the island. The power company said the were not hot, but I can't follow them back to see. Does the fact that they are two lines twisted together mean anything?
antigrassguy
ArboristSite Operative
That is an interesting configuration. Where do the twisted wires go to at other end? They look like ground wires, BUT with that many insulators would lead me to think there hot. Also where is the transformer for all those service wires and where do those service wires go? Two look to be going in same direction as ones in question. Are they the only power going to the island or is there a bigger one somewhere?
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begleytree
H. sapiens moderatus
With the line not grounded out, yes, consider it hot. Even an open circuit overhead that is not locked out (tied off to neutral) can be backfed either from other connections, or a customers generator.
I understand what they did (lacking more of a view along the line) because there is no clear neutral to ground of to. I looks like the jumper was wrapped back along the line and clamped off to itself. this is not an approved method of disconnection here, or anywhere else I have done storm work. The jumper is to clamp to the neutral so that any power comming in wether by line or backfeed would ground out, and blow the breakers on the line or in the home if a homeowner forgot to pull the mains.
consider it hot and don't climb near it until the utility certifies it safe. demand a lockout tag/do not energize tag on the pole and the line flagged as off. if it's truely off, its not but a bolt to drop the entire line to the ground. not too much to ask in exchange for your life Mike. imo, you did exactly the right thing.
-Ralph
I understand what they did (lacking more of a view along the line) because there is no clear neutral to ground of to. I looks like the jumper was wrapped back along the line and clamped off to itself. this is not an approved method of disconnection here, or anywhere else I have done storm work. The jumper is to clamp to the neutral so that any power comming in wether by line or backfeed would ground out, and blow the breakers on the line or in the home if a homeowner forgot to pull the mains.
consider it hot and don't climb near it until the utility certifies it safe. demand a lockout tag/do not energize tag on the pole and the line flagged as off. if it's truely off, its not but a bolt to drop the entire line to the ground. not too much to ask in exchange for your life Mike. imo, you did exactly the right thing.
-Ralph
Kneejerk Bombas
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The lower service lines go to the property I'm working at, the two transmission lines that are twisted together run out to the island, and they have more transformers out on the island (I guess) to service the homes on the island.
beowulf343
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One of the first things they taught me when doing line clearance-treat every line as if it's live! I've seen that mantra save lives-lines thought to be dead but back fed by generators, lines the power company said were dead but really weren't, etc.
antigrassguy
ArboristSite Operative
Can you see the pole where these twisted ones are hooked too? Is it possible that when they cut power to the island that they disconnect the primary and just attached it to the neutral to hold it there? Blow up your pic and look at where they are connected. Also on the hot primary look to the right of the insulator, is that part of the wrap or old hook up? As long as those are the ONLY wires going to the island and nothing from any other side, Id think they are dead....but Ive been wrong before.
Davey Dog
ArboristSite Operative
One more thing to think about with back feed... Transformers work with 120v the same as they do with 34kv on distribution lines..
Meaning if back feed does accure, it will be kicked up to the original 34kv rating....
On sub tranny lines it is much higher being in the range of 69-138 kv...
And tranny lines ar much, much higher being rated up 765 kv.....
Meaning if back feed does accure, it will be kicked up to the original 34kv rating....
On sub tranny lines it is much higher being in the range of 69-138 kv...
And tranny lines ar much, much higher being rated up 765 kv.....
Dadatwins
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By letter of electrical training 101 ALL lines are to be considered hot unless grounded. Tell the power company to ground it to be sure.
funny story
A few years ago during during hurricane cleanup a block of trees had knocked down several spans of poles and wires. My crew was ordered to clean up the downed trees so the power company could bring in their equipment to get the poles and wires back up. I met the power company rep on site and told him I wanted the wires grounded on both ends of the damaged spans before I would send my guys in to do the cleanup. He insisted the lines were dead and would not ground them out. We walked off the site. A couple of phone calls up the line to superiors and we were back the next day, same story from the power company rep. This time I asked him to write his name, title and statement that the lines were not energized on paper. He refused and said fine he will connect the ground lines as I had requested. He then proceeds to suit up with the rubber arm-gloves and grounds his bucket truck to a ground rod at the base of a pole. I sarcastically asked why he was doing all that if the lines were dead, and his answer was "he had to follow the standard procedure" Moral of the story, Don't do anything you are not comfortable with, and tell the power company to put it in writing and they will do whatever you ask.
funny story
A few years ago during during hurricane cleanup a block of trees had knocked down several spans of poles and wires. My crew was ordered to clean up the downed trees so the power company could bring in their equipment to get the poles and wires back up. I met the power company rep on site and told him I wanted the wires grounded on both ends of the damaged spans before I would send my guys in to do the cleanup. He insisted the lines were dead and would not ground them out. We walked off the site. A couple of phone calls up the line to superiors and we were back the next day, same story from the power company rep. This time I asked him to write his name, title and statement that the lines were not energized on paper. He refused and said fine he will connect the ground lines as I had requested. He then proceeds to suit up with the rubber arm-gloves and grounds his bucket truck to a ground rod at the base of a pole. I sarcastically asked why he was doing all that if the lines were dead, and his answer was "he had to follow the standard procedure" Moral of the story, Don't do anything you are not comfortable with, and tell the power company to put it in writing and they will do whatever you ask.
Manco
ArboristSite Operative
It is unbelievable how many accidents were/are caused by supposedly " dead" lines. By tree cutters and even linemen.
The standard procedure story happens quite often. On storms the linemen sometimes don't seem to mind at all gambling with your life. "Standard procedure" kicks in when its their butt that could get fried !
There are lots and lots of linemen with missing toes, fingers, hands, feet, etc. because they came in contact somehow with a "dead" line. Then, factor in all the close calls that resulted in a shock with minor injury that didn't get reported. NEVER accept "I think its dead" or, "Its supposed to be dead" as a criteria for working near a power line. JUst because someone has a power co. shirt on doesn't mean they're a lineman. They could be a meter reader or someone who is never out of the office except during storms. They possess less knowledge of the lines than most foreman on trained line clearance crews.
When in doubt, ask the lineman or whoever tells you its dead to prove it !
The standard procedure story happens quite often. On storms the linemen sometimes don't seem to mind at all gambling with your life. "Standard procedure" kicks in when its their butt that could get fried !
There are lots and lots of linemen with missing toes, fingers, hands, feet, etc. because they came in contact somehow with a "dead" line. Then, factor in all the close calls that resulted in a shock with minor injury that didn't get reported. NEVER accept "I think its dead" or, "Its supposed to be dead" as a criteria for working near a power line. JUst because someone has a power co. shirt on doesn't mean they're a lineman. They could be a meter reader or someone who is never out of the office except during storms. They possess less knowledge of the lines than most foreman on trained line clearance crews.
When in doubt, ask the lineman or whoever tells you its dead to prove it !
Manco
ArboristSite Operative
How far back do the lines stay doubled? That appears to be too long to be the jumper wire to hook back up to the primary.Maybe the angle.
The neutral or ground is on the insulator on the crossarm. The extra wire on the primary to the right of the insulator is tie wrap wire- to fasten the wire to the insulator.
From what this looks like it is as you describe to be a dead line. But as other posts mentioned, a common house generator wired in the breaker box can backfeed and step the voltage "via transformer" back to the lines original voltage ! Be absolutely sure and get the power co. to ground the lines on both sides of your work area.
The neutral or ground is on the insulator on the crossarm. The extra wire on the primary to the right of the insulator is tie wrap wire- to fasten the wire to the insulator.
From what this looks like it is as you describe to be a dead line. But as other posts mentioned, a common house generator wired in the breaker box can backfeed and step the voltage "via transformer" back to the lines original voltage ! Be absolutely sure and get the power co. to ground the lines on both sides of your work area.
diltree
ArboristSite Guru
My father told me a story about a storm that hit our area many years ago. Our company was a contractor for Boston Edison and was called out along with several other tree companies that had contracts with the Utility. My Dads crew and another were sent to remove a huge tree that had fallen on the three phase. The Utility guys said they had killed the power when our crew arrived on the job, the other crew had already set up and were beginning to work on the tree......and Zap! The wires were live! This is why the golden rule of line clearance is to treat every wire as if it is live, whether it is a 3-phase that was assumed dead or even if your trimming telephone lines for verizon.....this picture shows an insulator which is a clear indicator the line is charged at some point, proceed with caution. Mike is there bucket access? are you line clearance qualified?
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Kneejerk Bombas
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Thanks for the comments.
Both wires run out to the island. Could they just be 220V?
Here's the original photo (big):
Both wires run out to the island. Could they just be 220V?
Here's the original photo (big):
Kneejerk Bombas
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No and no.
What do those wires attach to on the island? or do you know. There's no connection to voltage on the pole any where that I can see. It seems the source of any current would be at the other end. What is on the island?
Kneejerk Bombas
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8 or 10 summer cottages.
asiegler04
ArboristSite Lurker
I would always assume the line is energized and be extremely careful.
oh yeah
diltree
ArboristSite Guru
Mike considering there is no bucket access and that you don't have experience around live wires, I would request for the utility to meet you on the job and ground out the line with you watching. If the utility will not meet with you; get an estimate from some one line clearance qualified and sub the job out, tacking on a few bucks for yourself!
