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Utility poles

blog.plover.com

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Re: Utility poles

#111

Post by eptil »

souprock wrote: post #37
pan69 wrote: post #6

I have always wondered about utility poles, they always seem very fragile. Why not just stick everything in the ground?

Florida has this solved. Wood rots and breaks. Burial has flood issues. The solution is to install better poles. Most commonly, the poles are concrete with a square cross-section. Some are round concrete, spun while hardening to allow a hollow interior. Some are galvanized steel, with perhaps a decagonal cross section. One near my house is about 2 feet thick, with a label that says 50,000 pounds. These are not fragil…

We have also started using ductile iron poles. They are much easier to drill and last longer than the galvanized.

Re: Utility poles

#112

Post by eptil »

shmerl wrote: post #31

I'm now spotting fiber optic cables on different poles :) They commonly use distinguishable splice enclosures which look like this: * https://fiber-optic-catalog.ofsoptics.com/Asset/Closure.jpg * https://thumbs.dreamstime.com/z/fiber-optic-enclosure-splice...

Your bottom picture also shows half of a snowshoe fiber slack storage location. They are used at almost every splice so the splice can be moved to the ground easily and placed into a splicing trailer. That fiber pictured is a strand and lash construction where a high strength steel wire is placed and then the fiber is basically tied to it. We have stopped using any of it in favor of ADSS fiber which means all dielectric self supporting. We can place it in the power space and avoid dealing with the communications space problems.

Re: Utility poles

#113

Post by eptil »

pdelbarba wrote: post #57
philg_jr wrote: post #36

Earlier quoted context omitted.

Something that completely fascinates me are cell towers/equipment. They are everywhere, yet I know almost nothing about them and rarely get to see them up close. Even less often (pretty much never) meet anyone who work on the equipment. I imagine each base station is basically a mini datacenter. I was at Mammoth Mountain recently for the first time and got to see the cell towers at the top of one of the lifts up clos…

I would absolutely love a big writeup on how they're set up and what the components are, as well as all the real-estate stuff that certainly surrounds them. I'm also noticing a lot of new towers that look like big cylinders on a pole, sort of like a TACAN so I often wonder what's up with that. I do know that the traditional ones are triangle shaped such that they each form the intersection of a hexagon tessellation (…

The cell companies are actually moving away from the large towers as 5g service is deployed in favor of microcells.

http://www.steelintheair.com/Blog/2017/04/top-10-things-the-...

They can be built into decorative lighting poles such that you would really have to pay attention to notice them.

Re: Utility poles

#114

Post by eptil »

dustinmoorenet wrote: post #81

I was looking at the transmission lines one day and was curious about why there are always 4 wires. Basically, 3 lines carry equal voltage phased 120 degrees apart from one another. This kind of power is easily generated from 3 phase power generators at the power plant. The 4th wire is a common return for all three wires. It is normally smaller than any single load wire because, if the power is distributed evenly, no…

Its not so much that you have to balance the load in a given area. You must balance the load beyond breakers as much as possible. If the load becomes too far out of balance, the much larger feeder breakers at the substations will trip to protect the grid upstream from the imbalance.

Re: Utility poles

#115

Post by sevensor »

ranger207 wrote: post #16
sevensor wrote: post #9

Earlier quoted context omitted.

> and not where it can have direct contact with people. Could you expand on that? My elementary school had a playground structure made of old utility poles. Other than getting pitch on our clothes, they didn't seem particularly hazardous.

They're treated with lots of preservatives. They're probably not all that dangerous in the short term (unless you eat some of the pitch), but it's annoying to deal with the potential long term safety. My scoutmaster worked for the power company, and I was going to ask him if we could have a couple of poles for my Eagle project, but after looking at what you had to do to reuse them I decided it was simply too much of…

Could be a lack of awareness, as this was several decades ago. We also had a jungle gym made from pipes set in a concrete pad.

Re: Utility poles

#117

Post by mjd »

Waterluvian wrote: post #2

I absolutely love reading about a topic from a super enthusiastic non-expert. I want to subscribe to a weekly series called "Reasonably Intelligent Person Obsesses Over Something"

Thanks! Can I suggest that you might enjoy following my blog regularly? In addition to utility poles, I have also discussed this year: Samuel Johnson's feud with James Macpherson, a fraudulent poet; the panicked history of England in 1533 after Henry VIII's mistress got pregnant; the Slaughter electric needle injector; how plutonium is used to power medical devices; equivalents of "Joe Blow" in Turkish and Hebrew. Also a lot of other stuff more or less random.

https://blog.plover.com/

Re: Utility poles

#118

Post by shaneford »

phasetransition wrote: post #100
Dangeranger wrote: post #84

Earlier quoted context omitted.

Most distribution transformers have a maximum rating of 200kVA. So depending on their voltage you can calculate the max amps by (200kVA / voltage). Minimum amps is a bit harder to calculate but I would make a best guess of 20% of the max 200kVA. You can read a bit more about the calculations here[0] [0] https://yorkcentraltechtalk.wordpress.com/2012/06/27/transfo... Edit: noted that 200kVA is the maximum rating, not…

Do the distribution transformers have "winter" ratings like the local center tapped step down transformers that feed houses? Around here it is pretty clear that Georgia Power doesn't pay much attention to the name plate ratings, winter or otherwise, when sizing and determining the number of homes per xformer.

Distribution transformers are not usually thought of as having a winter rating. On the other hand, distributions lines definitely do. Sometimes work on lines can only be done during the winter, because the load has to be shifted to lines that can only handle the increased temporary load during the winter.

There is a science and an art to sizing residential xfmrs. Generally is depends on the square footage, number of bedrooms and type of fuel used to condition the house.

Probably where GP is running into problem(like most electrical utilities) is that the use of electricity per square foot keeps going up.(caused by the increase of electrical devices in the home) So while the xfmr might have been sized correctly when installed 20-40 years ago, it is no longer sufficient. This causes problems.

Source: I was a distribution engineer for 7 years.

Re: Utility poles

#119

Post by mturmon »

blattimwind wrote: post #65
rdiddly wrote: post #61

Earlier quoted context omitted.

Correct, and more conventions in the US that are mostly true so don't bet your life on them: hot has black insulation, neutral white hot wire insulation will be smooth, neutral ribbed hot terminal screws will be brass, neutral silver (chrome)

Screw terminals in a house installation?!

Many electricians don't like to use "back-stab" or push-in connectors in receptacles, and prefer to use the screw terminals -- see, e.g., https://diy.stackexchange.com/questions/7977/when-to-use-hol...

Re: Utility poles

#120

Post by jsjohnst »

philg_jr wrote: post #36
Waterluvian wrote: post #2

I absolutely love reading about a topic from a super enthusiastic non-expert. I want to subscribe to a weekly series called "Reasonably Intelligent Person Obsesses Over Something"

Something that completely fascinates me are cell towers/equipment. They are everywhere, yet I know almost nothing about them and rarely get to see them up close. Even less often (pretty much never) meet anyone who work on the equipment. I imagine each base station is basically a mini datacenter. I was at Mammoth Mountain recently for the first time and got to see the cell towers at the top of one of the lifts up clos…

I’ll try to write up a blog post on it. The newer stuff I’m out of touch with, but I’ve worked on a good chunk of the gear you commonly see still.
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