Overhead URD

[harley]

I have been given the task of coming up with a way to put URD overhead because of tree issues. Don’t laugh; I live in the middle of tree hugger central. So I need your help with some of the issues:

1. Have you ever put a well bushing on an overhead transformer (I know TXU did at one time for transformers in a vault)?

2. Would you lash the URD to a support wire or sag it in to below the manufacturers spec?

3. Would you dead-end the URD with a pulling sock (becket)?

This is what I have come up with so far:

The cable has to be shielded so I went with URD

I need to use materials that are already in the storeroom (URD, elbows, grips)

The best part is they gave me less than 30 days to come up with the solution and generate a cost per foot for the conversion.

Thanks for any help

[topgroove]

I'm not so sure URD wire is durable enough for arial installation. Even if it were lashed to a messenger I would think the squirrels would love to chew on the concentric nuetral not to mention the UV beating it would take from the sun. If you had the slightest rub in a tree it would dammage the cable in no time. They make tree wire in all kinds of sizes that would work great. Its a bitch to skin but the stuff is practicly indestructable.If you have to go with the URD route I would lash it to 10M guy wire and use terminations to a open air cutout and then #2 copper into the transformer bushings

[Stanman, at ComEdy Il.]

Let the wizards in the office figure it out. If URD was intended to be strung it wouldn't be called URD. I'm sure they'll come up with something brilliant like management always does.

[harley]

Let the wizards in the office figure it out. If URD was intended to be strung it wouldn't be called URD. I'm sure they'll come up with something brilliant like management always does.
I agree - they want to use shielded cable because of the zero clearance requirements. The people with the polictical pull are the ones pushing this, not the poor sobs that have to put it up in the field.
Tree cable will not work because it is not considered shielded cable.
Thanks for the suggestions, please keep them comming

[alanbt]

i have run ug wire overhead several times, what size is the wire, insulating value and copper or aluminum? we used 4/3 1/0 messenger and lashed the wire to the messenger supported with tanget brackets

[harley]

1/0 alum. with a concentric nuetral XLP type. How did you terminate the wire to the transformer?

[topgroove]

Is it going to just one transformer? Also have you thought about spun arial cable? Its considerd shielded and is installed below the secondary.

[topgroove]

Aerial cable
Kerite pre-assembled aerial cable is fully shielded for personnel safety and can be installed in very narrow rights of way. This design features the same time proven Permashield® and EP rubber insulation system insulation system as in Kerite Power cables. The unique free-stripping insulation shield assures fast and reliable terminations and splices. Kerite Cable Services can provide turnkey installation.

go to: www.kerite.com

[harley]

Topgroove,

I have a catalogue with that Kerite cable in it. How do they terminate it? Have you ever worked with it. The designer doesn't want any cutouts on the pole. He wants to run 1 URD cable per transformer and terminate with an elbow on the top of the transformer. 2 years to retirement is my new mantra.

[topgroove]

I've always terminated it with a elastamold cold shrink terminations into a cutout or 600 amp disconnect. I suppose if you retrofit the transformers with well type urd bushings you could put a elbow on it and I'm sure it would work fine as long as you stripped the shield back and semicon layer.
I hope there's no more than three transformers involved because the spun aerial cable comes with three conducters lashed to a messenger. I'm also assuming its a wye primary.

[liledgy]

Com ed has been putting urd cable on overhaed poles for at leasst 4 years, 4/0 lashed to a messenger. they use it when the need a new feeder but don'y want to set new taller poles. They have had brackets break and damn near killes some people, now the heve small cable around cable connected to pole as a backup. Can't wait for an ice storm and see the poles start going over.

[dbrown20]

Good God! dbrown20

[Lizzy Borden]

You never mentioned 1phs or 3phs. Whats the load?

Whats wrong with Spacer cable or balogna cable. Fuse it and dont tell the designer........what they dont know wont hurt them.

Eventually the trees will rub through the insulation and burn up his tree anyway.

[graybeard]

You never said but but is there a reason that you can't make that part of the circut u/g?

[just say no]

hey harley,2 more years till retirement and your worried about that shit....

[dbrown20]

What's wrong with directional boring and going strictly URD? Too much money?

If a customer requests a change in his facilities the cost is his baby. At least where I have experienced.

Like someone said. Just use tree wire. Also you can build a platform on the pole for the pad mount. Please enclose a picture when you do this. Elbows can be pulled off the pd mt from the bucket. Please send video of this operation. We may be breaking new ground here. dbrown20

[harley]

The politics of this city is something to see. Being a muni you are directed by the city council to do things that make no business sense. After we get the test line up I will post some pictures. The end result is that they do not want to use tree cable; the cable has to be shielded. You can’t have a cut out on the pole because of tree clearance issues and this line needs to be installed on the rear lot line by hand. I can think of at least a 100 reasons not to do this stupid shit; but I am trying to make the best out of a bad situation. I have found that Central Moloney makes a bushing for the H1 bushing on a conventional transformer that you can plug an elbow on to. The load at this time will be residential, mostly single phase with a few 3 phase customer. The last thing I want to do it screw the guys in the field, I keep trying to talk them out of this but the Director and his flunkies will not stand up to the city council and tell them that we will not do this

They don't want to go u/g because of the cost and these f---up people might be inconvenienced.The people in the neighborhoods think the utility has no right to trim their trees and should also pay for burying the overhead lines. This is supposed to be a less costly way of making these assholes happy.

[topgroove]

The load at this time will be residential, mostly single phase with a few 3 phase customer. .[/color][/size][/font][/color]


I hope you decide to go with the kerite spun aerial cable. At each elbow your gonna need a feed through device. Elastamold makes a double bushing. That would let you feed the transformer and then continue that phase on to the next elbow. I hope you build it so if you ever have to work on it you can kill it and ground it cause your not gonna want to lift any energized elbows out of your hooks

[Stanman, at ComEdy Il.]

You still have to fuse that shit, even if you find a bushing connector! Besides stocking parts and new transformers that will adapt. Tell them the money that needs to be invested in case of needed repairs.

Also tell your management, "No one else in the world has anything like their talking about!" Or better yet, have them show you! It doesn't exist!

Like CHI.HAND said, we have some of that shit in the air! But you have to pull the mesenger to 5000 lbs.. So you have to anchor both sides real well. They are basically express feeders, no transformers, just disconnects at one end and a switchgear at the other.

Even if you get elbows on top of the trans. how the hell would you pull them? Especially in the rear lot. Tell them there is "no safe way" to do it! You wouldn't be lying! Elbows aren't intended for outdoor use, the weather would break them down rather quickly. I believe this would be a nightmare waiting to happen.

[dbrown20]

Where has your renegade ass been? Have missed your radical views. Computer been goobered up? dbrown20

[md2]

Peco puts all sorts of urd cable on messenger
we lash it with a j lasher...everything from single phase #2 15kv to 3 phase 750 35 kv...they use it for feeders, to go under another 33 circuit without tieing to it, for where the trees are too heavy and people don't want tree trimming... you have to crank the messenger up to 4000 lbs to set the pole before you pull the big stuff so you don't snap off pole while pulling. the messenger rides on big malliable iron clamps and get rings to help hold it up should the lashing break

[keithz]

They Make Overhead Tree Wire

[Squizzy]

We use aerial bundled conductor (abc) in areas with alot of trees. Done heaps of work installing the low voltage stuff. Have yet to install any of the high voltage gear its made (originally) by the French its all insulated and the HV is screened covered in HDPVC (high desity pvc) may be the way to go....

[harley]

We worked the job yesterday. Thanks for the all the advice, it did help alot. The job was replacing 3 poles and installing the URD. It was a pain in the ass. Lucky for us we were able to kill out the tap line to install the URD. I would not want to try to lash in the primary zone with the primary spread out. They want to do this s-it on the property line. The transformer will be changed out next week as we could not get the well bushing in on time . The job had to be worked this week for a cost and construction presentation to the city council. I will post the pictures in the photo section
Questions?

[THE KID]

Harley,

The pictures on Powerlineman.com putting in URD as overhead from you?

[edski104]

yes ,i wish that the people who ask us to do miracles would have to work on some of the stuff that they have us come up with to get the job done. no cutouts to a can,so if one goes bad,you have to take out the whole loop to replace it. nice.good luck,brother.in boston we had to put up,oh god i can't for the life of me remember the name of them right now, in vaults for multiple feeding of circuits from one feed.shit.like a 4 way feed thru. we had to put them up in the air on crossarms and make up elbows to feed the overhead when we were doing a large conversion from 4KV to 13KV. thought it was kind of sllly. still do.if anyones ever in boston,look around,lots of them still up.

[harley]

Harley,

The pictures on Powerlineman.com putting in URD as overhead from you?

yes, that is us installing the URD

[CenterPointEX]

"Keep Austin Weird!"

[Linemanblood]

Hendrix cable is the ticket. It will take any and everything such as sun , squirrels metal rub. etc

[linemanfrog]

Tree cable (hendrix) is a much better alternative than stringing URD. We have been using it for years and have learned a few things. First and foremost, DO NOT use the 7#8 alumaweld for the messenger. This is what the company will attempt to sell you on. The problem is that when a something larger than a limb falls on it you break just not the nearest pole but possibly a few poles. (Although it is good for overtime =) ). We started stringing the cable in without messenger to prevent all the broken poles. We frame for standard bare conductor spacing and use chiken wings to put the insulators on. Another option if your company "must" use the messenger configuration is to use #4 ACSR or #2AAAC.

Also buy the grips designed for the conductor. It should look alot like a flat grip but be scalloped (not serrated). the serrated grip will end up slipping alot especially on wire that has been in the air a long time.

Also remember that just because the insulation is no the wire it should still be treated just as you would treat a bare conductor since the insulation has no safety rating and is exposed to the elements continually.

[harley]

We have used Hendrix in some locations, but Hendrix is not shielded cable. For a cable to be considered shielded it has to be grounded on the outside ie: the concentric on the URD when hooked up to the neutral acts as the shield.

[lweford]

Look at these pictures. I thought this was pretty good idea for the tx poles. They used a feed through with elbows so they could deenergize the tx if needed. I figure they used a 3M pothead straight into the tx bushing.

http://www.powerlineman.com/pictures/2006/august/king/king.htm

[Budda]

Harley, have you considered Hendrix vice ug

[PA BEN]

Look at these pictures. I thought this was pretty good idea for the tx poles. They used a feed through with elbows so they could deenergize the tx if needed. I figure they used a 3M pothead straight into the tx bushing.

http://www.powerlineman.com/pictures/2006/august/king/king.htm

Are the pictures on the old picture page? If so how do you find them? Maybe you could post them on the new page:D

[tramp67]

I was on a job once where we wrecked out a bunch of what the utility called "tree wire", but was in fact URD lashed to 3/8" guy wire, which in turn was attached to trees with D.A. bolts and three bolt clamps. The URD ran down the tree trunks to feed ranch runner transformers. They finally decided to bury new cable underground because they got tired of all the outages from the cable faulting out all the time. The insulation would break down from the constant movement while it was energized, and also the occasional bear chomping into the cable didn't help it much either. Must have been another one of those big brainstorms by someone that doesn't have a clue.:eek:

[old lineman]

Hamilton Hydro in Hamilton, Ontario, Canada has be using URD bushins on their overhead TX's for decades. The receive their TX's from the supplier built to spec.
They use URD elbows and URD cable for the cable to primary bushing.
This was done to avoid tracking problems from an era gone by where the air borne polution used to causing tracking and burn off problems.
Their official company name has been changed to Horizon Utilities.
Check it out and see what they can contibute.
The Old Lineman