Why No Improvements?

Huh? Our telco stuff is still all overhead, just like the power.

But not as cheap. Since there is no financial penalty for poor reliability, cheap wins.

Good advice.

I find it curious that "underground" is assumed to mean "reliable."

Yes, small overhead lines are vulnerable to tree limbs, etc., but it is hard to beat air and ceramic as reliable insulators.

Buried cables are not exposed to the elements in quite the same fashion as overhead lines, but soil movement, water entering cables and construction (digging) are all real risks. Too, while the mean time between failure may (or may not) be better for buried lines, I'd bet my boots that the mean time to locate and repair the failure is much, much longer.

LV buried cable might be more reliable in terms of failures/yr/foot, but I wouldn't want to bet on MV and up.

Any solid statistics out there?

Thanks >>

Buried utilities sound great until a couple of feet of salt water goes over them. You can drive a truck through 6" of water and fix a wire on a pole but these guys don't want to wear SCUBA gear to get to them.

So why not get the engineers to work on some better way? Is it under study?

My neighborhood is all new and all utilities are underground. We only lose power when the feeder that goes many miles thru older sections goes down. Makes me think the technology is available, just not used. If so, why?

Thanks again!

Because you've already got your answer: there is no monetary incentive to increase power reliability to residential customers. Dollars are all that counts.

FWIW where I live we have all our l> So why not get the engineers to work on some better way? Is it under > study?

$$$$$$$ Imagine what it would cost to replace all the overhead cables with underground cables.

in article Oy5%c.86378$4o.51371@fed1read01, ShoNuff at snipped-for-privacy@papernapkin.net wrote on 9/6/04 3:32 PM:

$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

If you give them enough of yours, you can have them bury the feeders.

Bill

Some areas the power supply is buried underground but surprisingly to me, this actually costs more than the pole method, so many areas just put in the poles. Keep in mind that many places the telco also runs its wires on the same utility poles.

I work as an electrical distribution operator/dispatcher and I agree will all the statements made in reply to the person's concern over our ancient distribution. Because of deregulation, electrical distribution companies are profit driven. The statement, "There is no monetary incentive to increase power reliability to residential customers...dollars are all that counts" is true to a certain extent. Companies have to weigh in the amount of Public Utilities Commission complaints made and profits made. Some corporate companies are beginning to invest there OWN money in new construction of switchgear and lines to increase reliability. This way, if a distribution line fails, a tie breaker will close into a different line. Underground development for electrical distribution began, I believe in the early 1970's. At that time, the insulation was of poor design and the techniques for burying lines were inadequate. That is why most of underground line failure is associated with old developments. But that is not always the case. For example, my development is underground and is fairly new. Just recently, a single phase line feeding the development went bad. My power was out for 40 hours! If my development was overhead, a lineman could easily go to an upstream fuse protection device and trying throwing a fuse in to see if it holds. MOST of the time it works. And power usually get restored 1-3 hours in non-storm situations. Causes are squirrels, bad arrestors, wind, tree branches and lightning. In underground, it is more involved. Once the fuse upstream doesn't hold, a crew has to use special equipment, which send signals down sections of cable and determine where the fault is. The process involved and time consuming. Overhead distribution will most likely not be converted to underground, because at the time of development, it was more cost-effective to go with overhead. As new developments are planned, the cost of underground is configured in with all the other construction costs that go into a development. Electrical distribution companies usually don't pay for new construction. So we are pretty much stuck with we have.

Dan

040906 2047 - BFoelsch posted:

Yes, and imagine the explosion that would occur with a backhoe striking a

48KV underground cable. Just in this summer construction season around this area construction crews have damaged several underground gas lines. Nobody ever thinks to check to see what they are digging into before they dig.

I have been putting MV( up to 35kv) underground for 15 years. Works just fine as long as the correct cable and conduit are installed.

Locating faults is not hard at all. We use an tracker on the grounded cable and you can find the fault pretty quickly. I have never seen an cable fault at any where other than physical damage, the terminations or splices. Terms and splices are in accessible places so they are not hard to get to.

There are a few HV underground installations that I know of. The cost of the cable is tremendous and usually HV is overhead because of that.

[snip]

Not to mention how much deeper you'd have to dig to set all those underground poles. ;-)

I once had a text file that described a repair to a HV (230KV, I believe) line somewhere in the LA area that was quite interesting. One line (paraphrased) was "I didn't pay any attention to the construction until I saw liquid nitrogen trucks at the site. That got my curiosity up..."

Unfortunately that file was lost in a disk crash long ago.

| I hope someone here can explain why, after all these years, that the power | companies have not come up with a better distribution method than poles and | wires. | | Every time there is a storm, people lose their electricity because something | blew, or more commonly, a tree fell and took down a line. | | Why doesn't the power company just bury the wires much like the phone | company has done? It seems that with all the knowledge and genius we have | in the USA that someone would come up with something more reliable.

There are plenty of installations underground, at least in part. But the higher the voltage gets, the more expensive it is. How much more would you like to pay on your electric bill?

Here's an example of an underground transformer:

$file/SDTOverviewPrestion.pdf Now we can't call them "pole pigs". Anyone got a good name for these? Maybe "ground hogs"?

| When I asked my local power company about it, she told me to go buy a | generator!!

They didn't try to sell you one? Some power companies are doing that.

I live in a neighborhood with underground utilities. Last year the transformer (located in MY yard unfortunately) had a seal failure in winter and blew up. No real damage to my property, until it was time to replace it. The tractors etc. necessary to swap the vault (too small for new xfmr) and the cranes did major damage to my landscaping, none of which was covered by the utility. They claimed that it was my responsibility to keep landscaping away from their right-of-way, as shown on my deed. In addition, it took almost a week to accomplish this, during which our entire 3 block neighborhood was without power. I can only imagine that a pole pig would have been swapped out in less than a day. Attached are pix of the "grand operation" involved.

6 months later, the 11kV primary feed for that xfmr had an insulation failure 20 feet away, probably as a result of the earlier xfmr problem. The cable was buried beneeth the sidewalk and the force of the explosion underground cracked and erupted the sidewalk concrete, as well as damaged the telco lines and TV cable buried in the same area. All 3 systems were down for another week waiting for coordination of the sidewalk removal, street blocking, parked car removal for tractor access etc. etc. etc. Again, I doubt that an overherad line failure would have taken so long to fix.

Along the same lines (no pun intended), the Telco system was installed in the 1970's when the tract was built, and they had the "foresight" to imagine that everyone in the neighborhood would want 2, count-em 2 phone lines per house. So that is EXACTLY how many conductors they buried. Now days of course, everyone wants a fax line and a DSL line etc etc,, plus over 30 years some of the wires have failed, so the telco is completely out of hard wires. They want to assess us over $1600 per home for the cost of diging up the sidewalks to replace the phone cables. In my old 'hood they simply added cables to the poles one day and offered me 4 extra lines for a nominal monthly adder.

Underground is no panacea, it just looks better IF you can afford it.

[snip]

You need to look at the line extension tariff that the telco has filed with your state utilities commission. In these parts, the telco (and any other utility) can only charge for a line extension if they have _no_ facilities serving your property. Once they have a line in, its their responsibility to upgrade it in order to provide service. The 'gotcha' here is that things like DSL might not fall under their definition of a regulated service, in which case they can charge you what they want.

The trick is to order the additional line as a class of regulated service and then, after they dig everything up and upgrade, drop that service and order a DSL line. "Why look here! An unused pair running right up to my house!"

| You need to look at the line extension tariff that the telco has filed | with your state utilities commission. In these parts, the telco (and any | other utility) can only charge for a line extension if they have _no_ | facilities serving your property. Once they have a line in, its their | responsibility to upgrade it in order to provide service. The 'gotcha' | here is that things like DSL might not fall under their definition of a | regulated service, in which case they can charge you what they want.

But that would only be for the DSL service.

A friend of mine had 2 phone lines in use. He ordered a 3rd and they pulled in another 2 pairs (no charge). Then he ordered 2 more pairs (5 total). They wised up and this time pulled in 25 pairs (no charge).

| The trick is to order the additional line as a class of regulated | service and then, after they dig everything up and upgrade, drop that | service and order a DSL line. "Why look here! An unused pair running | right up to my house!"

Or mention how your local cable company is now providing VoIP.

Yes. And any line improvements needed to support it.

That makes no difference to my local phone company. Their management has determined that the expense of lobbying congress to kill VoIP is far less than that required to provide competing service.