Major damage due to a seagull...

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mxslick

mxslick

Senior Member
Location
SE Idaho
At 7;15 am this morning I was awaken by the familiar sound of a major powerline fault. Looking out my bedroom window I could see the 16kv feeder lines bouncing around violently, so much so the pole outside my window was swaying.

As I got dressed the fire dept. showed up a block away. I walked up there to see a pretty incredible sight: FOUR full spans of 3-phase 16kv lateral burned to the ground, a badly damaged car that one of the phases had landed on, and up the street a poor dead seagull laying on the ground.

The bird had gotten across the lines and the resulting fault burned down over 1,000 linear feet of #4 solid copper feeder, leaving literally thousands of chunks and bits of the wire scattered over a full city block and leaving several homes and apts. with no power. A line crew is due to arrive shortly and begin reconstructing the lines.

One question pops up in my mind: why wasn't that lateral fused? I think a simple set of cutouts would have prevented the carnage.

I have taken video of all the damage (pretty impressive) but have no way of uploading it..if I do get it uploaded I will come back and post a link to it.

During the event our 4kv lines that serve my apts. went through a few sags.
 
ItsHot said:
Apparently everything the poco has is not protected??:-?
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More true than you may think....I have not noticed any fuses on any of the laterals in my area...a stupid design flaw since those skinny #4's are served by a feeder that is at least 500kcmil.

electricalperson said:
isnt there a recloser on the lines to stop this kind of damage?
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There is, on the main feeder. It was set to one-shot as the line only tried to clear once, thankfully. One of the phases was down on the 4kv phase that serves my building...it was in contact with the street and must not have had enough of a path to either blow clear from the 4kv or arc to the street.

In the underground fault on that same 16kv feeder a few years ago it tried to reclose three times..I wonder why it didn't this time?



LawnGuyLandSparky said:
I think utilities want that kind of fault to blow itself clear... and not cause an outage.
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Yes, but it should not blow the lines down in the process...literally four full spans of lateral, all three phases, are gone. The line crew hasn't shown up yet to start repairs...this is an outage of at least 50-100 customers who will most likely not see power until late tonight.

Again, some where someone in the POCO made (or didn't make) a decision that would have/could have prevented this whole situation. A simple set of cutouts on that lateral would have resulted in some blown fuses and a short outage for a few folks.

I'll try to get some shots with my still camera so I can upload them here.
 
I have found that with many utility's they will try to meet the reduced outage requirements of the state utility commission, by using larger OCPD's, at times much larger than the line can handle, allowing for a burn free instead of just having an outage in a much larger area.

I too have a problem with this as this could cause much more damage then just a line dropping to the ground.

But one of my pet peeves is they don't have much to prevent over voltage for long durations. We just went through one of these for the second time in about 5 years, in which a 69kv ling was dropped down on a 7200v line. in both cases it lasted over 15 to 20 seconds! and thats allot of cycles in electric terms. both times we lost a few houses to fire because of cheep TVSS plug strip's, these plug strip's have the on-board OCPD after the MOV's in them and when subject to long term duration OV surge tend to melt down the plastic housing that most of these plug strips are made in, add flammables close to these strips and you got a fire.

I have been in touch with UL to try to get them to force the OCPD's to be installed ahead of the TVSS device's but they replied that they don't control the manufactures design in this area.

My suggestion would be to install a one time fuse , maybe a thermal type, that would force the consumer to replace the strip in this kind of failure mode.
 
from what I've seen, to utilities, the conductors are the fuses. but I never did any line work, so I don't really know jack.
 
mxslick said:
. . . FOUR full spans of 3-phase 16kv lateral burned to the ground, . .
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Is it overhead spans or underground lateral conductors? Also, are you sure it is 16 kV? Normally, we stay with 15 kV class equipment or go up a bit to either 23 kV or 34.5 kV. I am also confused about the mention of 4 kV (normally 4.16 kV) in the area, is this a distribution voltage in the area that overbuilt higher voltage lines got into? :confused:
 
charlie said:
Is it overhead spans or underground lateral conductors? Also, are you sure it is 16 kV? Normally, we stay with 15 kV class equipment or go up a bit to either 23 kV or 34.5 kV. I am also confused about the mention of 4 kV (normally 4.16 kV) in the area, is this a distribution voltage in the area that overbuilt higher voltage lines got into? :confused:
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Hi Charlie:

These were overhead spans.

Yes it was 16kv (odd, but then again this is SCE territory). My area is served by 16kv for customers on North/South bound streets and 4kv on the East/West bound streets. :D

Luckily the 16kv jumpers from the feeder burned clear very fast and made very momentary contact with the 4kv, but the wire from the 16kv was still attached to the dead-end and touching the 4kv when I got to the scene. As I'd mentioned it was kinda odd that it was not arcing to the street when I got there.....the line repair crew were a bunch of great guys, they even gave me the set of dead-ends that had one bell shattered and burned. I'll post a pic of it with the others later.

I have some pics that I will post shortly. I do have one of the unfortunate bird but it is a bit too graphic for here.
 
The size of the conductors doesn't matter as much as the class of construction. If this was "main line" primary distribution, some electric utilities will use larger conductors like 397.5 kcmil or 795 kcmil out of the substation and reduce the size after getting out a ways from the substation. With this style of construction, we start out with 795 kcmil and change to 397.5 kcmil about a mile or so away from the substation without any overcurrent protection except the substation breaker. The #4 Cu. was probably left over from a conversion to the higher voltage and may or may not be changed in the future depending on the power requirements of the area. Since there is 4.16 kV in the area, they may still be in the conversion process. :smile:
 
Here are some pics from the outage:

Melted copper at the curb:
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Copper residue in the street:
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Wire remains and copper bits just across the street from the jumpers:
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More sidewalk bits:
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Interesting melt pattern on the walk:
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A look at the burned jumpers and damaged dead ends:
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Closer look at burned jumpers:
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Damage to the car, the powder is from a dry chem extinguisher, note copper deposit on windshield:

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More to follow in the next post!!
 
I have personally witnessed a goose flying down mainst West hampton beach about 15' off the ground.Where the primary crosses it changes from 3 vertical to 3 horizontal insulators and this is where the goose flies wing tip to wingtip 13.2kv. I saw a 12 foot round plasma cloud that looked like an orange sun and hauled my butt to where the goose was on the street shaking his head asking what was the number on that truck?? Right in front of the post office and the local paper took my pic with the goose. Timing is everything in life.
 
quogueelectric said:
I have personally witnessed a goose flying down mainst West hampton beach about 15' off the ground.Where the primary crosses it changes from 3 vertical to 3 horizontal insulators and this is where the goose flies wing tip to wingtip 13.2kv. I saw a 12 foot round plasma cloud that looked like an orange sun and hauled my butt to where the goose was on the street shaking his head asking what was the number on that truck?? Right in front of the post office and the local paper took my pic with the goose. Timing is everything in life.
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You know, of course, we will need to see that pic.:wink:
 
More pics and info:

More pics and info:

Here are more pics and info from the Jonathan Livingston Seagull incident.

Right after the outage, the one remaining line heading north you see was not burned by the fault, but it was replaced:
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The burned insulator dead end from the middle phase:
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The crack from that same insulator:
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More wire bits, these were across the street from the pole line!:
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Next-to-last transformer pole in the three-phase side of the lateral, fuse cutouts were opened by the POCO trouble crew:
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Burned sidewalk at a residence on the pole line side:
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Arc mark on the gate of that same residence:
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Mid-span pole transformer, note cutouts still closed:
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Some more data:

Initially, over 400 homes were affected by this outage, and one jumper to another lateral blew open during this incident all but the affected block had power restored within an hour;

Trouble crew agreed with my guess that this started as a phase-to-phase fault from the gull, then escalated into a full three-phase fault and also one phase went phase-to-ground, they confirmed that the breaker at the substation was set to one-shot and left there after the underground fault on the same feeder a few years ago;

The car that burned in my previous post was across the street from the pole line, the one outside phase blew all the way across the street and almost hit two other cars;

The contract line repair crew showed up around 1:30pm local time, and in just over six hours had power restored to all of the customers but one on the affected lateral (a taco place with lousy food, they were fed off a three-phase bank at the end of the lateral and failed to get an electrician on site in time to verify correct phasing for their service, a POCO crew later closed in the bank after verifying the rotation was correct.);

It took four bucket trucks, two digger trucks, and twelve men to repair this damage.

The line crew workers and foreman stated that this was the worst incident caused by a single bird contact they had ever seen.

Also an important correction: the wire serving this lateral is #6, NOT #4 as I had stated in my opening post.

We now have some nice shiny new copper in the air, but they STILL didn't install cutouts. Maybe after it burns down again...
 
Thank you. They only show a small percentage of the damage, I would literally have to take at least two dozen more to capture the full scope of the mess.

Talking to some of the residents while awaiting the repair crew I was told of how much of a light show it put on and how incredibly loud it was as well. One fellow less than 100 feet away saw the fireball on the jumper pole and said it was very bright and frightening.

A lot of luck was with many people on this incident...the sidewalks that the feeder and lateral follows and where the jumper pole is located are normally quite busy, especially in the morning, there are a lot of folks and kids walking around in the morning. I shudder to think what could have happened to anyone walking in that area when this went down, as there would have literally been nowhere safe from either flying molten copper, flying wire bits, electric shock or arc flash burns.

My apt. is over a block away with houses and trees between, and even with my front door closed it was loud enough to wake up me and scare my cat...it even set off a car alarm in front of my building!

I have over an hour of video I took during the aftermath and repairs, I will get it edited down and put up on Youtube as soon as I can.
 
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