Future: DC yes, AC no?

June 25th, 2016 at 11:23:39 AM permalink
petroglyph
Member since: Aug 3, 2014
Threads: 12
Posts: 1940
Quote: Face
For real =)

I make my living on the road. As far as "dangerous jobs" go, sitting defenseless and invisible to most of the pop has gotta be right up there. And the pay's gotta be a damn sight better. And no Xmas rush? Where do I sign?!

I could hold a chopper steady, I'm sure. OK, not sure, but willing to try! =D
I think the local union near you is Local #3, New York?

Call them, demand paperwork and tell them you are trying to meet the country's energy needs. I think you would be a shoe in.

I'd proudly send you my belt and hooks.
Everyone gets thrown from the plane to maintain altitude
June 25th, 2016 at 1:39:30 PM permalink
Pacomartin
Member since: Oct 24, 2012
Threads: 706
Posts: 8142
Quote: petroglyph
I'd proudly send you my belt and hooks.


Can I ask a question since we are on this subject. There is a 50 yard spur into my next door neighbor's utility easement which is heavily wooded with old growth trees. They have a single utility pole and a 7200V line running to that pole with a 50 kVA transformer that feeds three homes and a garage apartment.

The kicker is that one of the homes feeding off the 50 kVA is about 150 yards away, and they string the drop along two intermediate utility poles. The first 50 yards simply doubles back underneath the 7200V line.

We just had a fire caused by a tree blowing into a 7200V line. The utility pole had been damaged for years and was leaning over half splintered into the tree. The power company refused to replace the pole even though it was visibly damaged. Finally one windy night the tree blew into the line and caught on fire.

I asked them if they could relocate the 50 kVa transformer off the heavily wooded private property and put it back on the street where it would be safer. Right now the trees are almost 70-100' higher than the utility pole, and they could drop branches onto the 7200V line.

Driving around the area I can't see any other place where such an odd arrangement is done, so I think it is relatively unique.

================
I called the utility and asked about the 150 yard 240V "drop" to the house that uses two intermediate utility poles. It says on their website that 50 yards is their maximum "drop". They told me that the "drop" is actually a mechanical term and is defined as the distance from the last pole to the home, and has nothing to do with the length of the 220-240V line.

The wikipedia article is unclear as to what a service drop means.
https://en.wikipedia.org/wiki/Service_drop

That doesn't seem right to me, as there has to be a limitation on how long the 220-240V cable can be, or losses would be too great. I always though the drop was the length of cable from the transformer to the meter.

Service Drop: The overhead conductors between the utility electric supply system and the service point. These utility conductors are not covered by the NEC. Service Drop conductors are covered by the NESC. The service drop conductors are utility wires and connect to the premises wiring system at the service point. They are normally installed by the utility according to the National Electrical Safety Code (NESC). The overhead service conductors are part of the premises wiring system and are installed by an electrical contractor according to the National Electrical Code (NEC).

June 25th, 2016 at 2:43:09 PM permalink
petroglyph
Member since: Aug 3, 2014
Threads: 12
Posts: 1940
Quote: Pacomartin
Can I ask a question since we are on this subject.
Absolutely.

Quote:
There is a 50 yard spur into my next door neighbor's utility easement which is heavily wooded with old growth trees. They have a single utility pole and a 7200V line running to that pole with a 50 kVA transformer that feeds three homes and a garage apartment.

The kicker is that one of the homes feeding off the 50 kVA is about 150 yards away, and they string the drop along two intermediate utility poles. The first 50 yards simply doubles back underneath the 7200V line.
I think national standards are a max. of 350ft. IIRC The longer the service the more "line loss" there is in the voltage. Your electric service voltage is only guaranteed to be 120v +/- 10%. That blew me away when I learned that one. I almost posted to that when you mentioned Mexican utility's boosting voltage to increase service fees. I think Kenarman said, if you raise the voltage it lowers the amperage according to Ohm's law. Ohm's law being Voltage = amps times resistance. Resistance being the load. To figure power expressed in watts, the formula is volts time amps will equal watts or P= E I.

So as far as the Mexican utility boosting voltage [I heard that rumor years ago as well], in most cases it does not theoretically change the watts or kw consumed. If you boost the voltage to a water heater coil for instance, it lowers the amperage but watts to maintain a certain water temp stays exactly the same. If you increase the voltage to a motor it turns faster, so if for instance you were powering a drill, it would turn faster and the hole would get drilled faster, consuming the same amount of watts. Admittedly there is some difference causing light bulbs to burn out faster. Take an air conditioner as a last example, if you boost the voltage [and lower the amperage], the room cools quicker and the thermostat turns off the air conditioning until the temp rises to put it back in cooling mode?

So, back to the right of way. The 50 yd. distance is a company policy, it varies according to company and the size and height of the conductor. There are laws about how high the wires must be. For instance it has to maintain a min. of 15ft. over roads. Usually below the power is other cabling, tv and phone, so that elevates the electricity a few more feet.

I think your concern is at minimum two fold. Safety comes first, and lets face it, a power line in your face is unsightly. I have a transmission line in my back yard that I see every time I look south. I think it is some kind of pennance for all the beautiful vista's I have taken part in ruining, placing power across the wilderness?

Did you say you are a customer of PP&L or Pacific Corp? They have easement to put all kinds of ugly things in our view, but I have seen them challenged and lose. I will guess they have a thirty ft. easement into your neighbors property? So the line is in the middle, with 15ft. to be maintained by the power company on either side. That easement includes limbs. If an owner has a tree 20 ft. from the line, and the limbs encroach on the line row, the power company is obligated to trim those limbs. Many a court case has been decided over this dispute, some owners don't want them trimmed, some do. But it is absolutely a safety hazard regarding any limbs that can touch the line, or any "dead" trees that possibly could fall into the line for the company to make their best effort to remove.

If this pole you mentioned has a large split in it, causing it to lean [all wood poles have splits] and you told them about it, they are being negligent. If it sparks near these wires, or caused a fire or outages and you called it in, unfortunately " the squeaky wheel gets the grease". Every power company I have worked for [dozens] have done what they call "delayed maintenance". Basically they have lists of work that needs done, and they are postponing it. When I worked for PG&E in Portland during ice storms, it was easy to tell when the damage had reached there one million dollar deductible, after that no expense was to great, before the million they nickel and dimed it. [My opinion].

The problem with the length of service is voltage drop. Depending on the size of wire the line per ft. will lose x amount of volts. The power company only has to get within 10% of the declared voltage, so if they are saying it is 120, they only have to provide between 108 and 132v. That is a noticeable change in the lighting in our houses. We can tell every night here at 11pm, they switch something and our lights dim.

Many of these transformers have a dial on them, [which moves the tap on the secondary coil] which will raise or lower the output voltage on the secondary. It was put there because of voltage drop over long distances on the primary, but is also a tool for instances like the one we are talking about. The customer there with the short drop has a higher voltage then the customer with the long one. There are also physical limitations on the last length between the pole and house. In order to keep the elevation at the minimum clearance at the bottom of the parabola of the wire, tension is pulled at the ends. The problem here is, if they pull to hard, it destroys the masthead at the house. The company has probably adjusted the dial in order to give the furthest customer 115 or so volts, [during mid day]. That might say make the closest customer 122? Night comes, week ends, load on the line changes, house voltage changes.

There is possibly some complaint here that will effect management, but usually has to be safety related which it appears you have picked up on. They usually aren't willing to change anything, once it is installed. But they are not immune to exposure or complaints. They are in fact very sensitive to complaints, but they don't want you to know it. Call your states PUC, public utility's commission. They have a customer complaint dept. and tell them what you have said here about the broken pole, the sparks, the flame, the danger to you and your family and mention the manager by name who refused to do proper diligence on this obviously life threatening condition. Heads will roll, so will trucks. Take a picture of the split and the lean, and send it to the PUC.

My theory has always been to hand them a bigger hammer. If the person you speak with at the PUC hasn't spoken with the manager of your power company, CC it to your state senators complaint dept, and cc it to the power company. If you want the trucks there within a week, find out who your power company's insurance dept. is and cc them.

Paco, I don't know if I answered anything or just rambled? You need to go around the voice that won't hear.
Everyone gets thrown from the plane to maintain altitude
June 25th, 2016 at 4:25:07 PM permalink
Pacomartin
Member since: Oct 24, 2012
Threads: 706
Posts: 8142
Quote: petroglyph
I think your concern is at minimum two fold. Safety comes first, and lets face it, a power line in your face is unsightly. I have a transmission line in my back yard that I see every time I look south. I think it is some kind of pennance for all the beautiful vista's I have taken part in ruining, placing power across the wilderness?


As near as I can tell they put the utility poles across the creek in 1920. They started with ~4 poles to serve one 19th century home, then when a second home was built in late 1920's, they simply added four more poles to reach it. I am not sure when the pad mounted transformers and underground feeds became common, but most of the homes in the township are fed that way. Another 9 homes in this subdivision were built from 1954-1963, but since the lots were large because of lack of sewers, they didn't put anything underground. Now we have 14 utility poles and 7 transformers feeding 12 houses.

Unsightly is an issue, but it seems almost impossible to bury the whole neighborhood power lines. But as far as I can see, PP&L avoids putting the 7200 Volt lines onto easements on private property except in some cases where there is a mile long stretch following a tree line planted in the 19th century. Other than that they stick to the roads.

In this case it is a single pole on private property. They replaced both the utility pole and the 50 kVA transformer about 4 years ago, which would have been a perfect opportunity to relocate it to the street. I don't know if you can download some images from my drive.

https://drive.google.com/file/d/0B4r7l039-pqHcnNxMWg5WU4xelk/view?usp=sharing

The split pole was a different one that was nearby. They didn't replace it until there was a fire and they had to send out a crew on a friday night to cut down branches and replace the pole. It screwed up an event
June 25th, 2016 at 6:59:24 PM permalink
Dalex64
Member since: Mar 8, 2014
Threads: 2
Posts: 1766
V = I x R

V / R = I

If your load is a lightbulb, or a toaster oven, it has a fixed resistance. If you give it more voltage, you will get more current.
V / R = I
2V / R = 2I
Double the voltage, you will double the current. The resistor will get very hot.

If the Mexican utility is charging more for higher voltage, and billing by KWH, it is justified. The higher voltage will give higher amperage, disspipating/providing more Watts (work)

That is the simplified, more general DC explaination. AC power calculations are somewhat more complicated, but the same general ideas hold in the simple cases.
"Everyone is entitled to his own opinion, but not to his own facts." Daniel Patrick Moynihan
June 25th, 2016 at 8:00:12 PM permalink
petroglyph
Member since: Aug 3, 2014
Threads: 12
Posts: 1940
Quote: Pacomartin
As near as I can tell they put the utility poles across the creek in 1920. They started with ~4 poles to serve one 19th century home, then when a second home was built in late 1920's, they simply added four more poles to reach it. I am not sure when the pad mounted transformers and underground feeds became common, but most of the homes in the township are fed that way. Another 9 homes in this subdivision were built from 1954-1963, but since the lots were large because of lack of sewers, they didn't put anything underground. Now we have 14 utility poles and 7 transformers feeding 12 houses.
I have seen where a utility company just assumes they have easement, and a landowner or two has taken them to task with their state PUC. Utility's are in this battle constantly. The power company may not have easement, and it would be fairly easy to get them to do what you would prefer, if they do not. It would be on the title description if there were easements given. Another thing I have seen is, just because the power company has an easement, does not mean the phone and cable company have easement. They may be trespassing. Somewhere there is someone else's mistake here, when you find it, they become much more agreeable.

Quote:
Unsightly is an issue, but it seems almost impossible to bury the whole neighborhood power lines. But as far as I can see, PP&L avoids putting the 7200 Volt lines onto easements on private property except in some cases where there is a mile long stretch following a tree line planted in the 19th century. Other than that they stick to the roads.
When there are permits to develop an area, the utility's are spelled out in the permitting. For your entire area, it may well be agreed that there will be no more overhead service unless it comes from an existing source. When residential UG became popular in the west during the 70's, power company's learned a very expensive lesson putting power along back property lines. When the original lines were laid access was easy. Years later many people built fences and had landscapers and grew expensive ornamental trees, etc. The cable is only viable for around twenty years, and often fails sooner. Going into those backyards and replacing and repairing the lines and making all the landowners happy about the damage, cost fortunes.

Quote:
In this case it is a single pole on private property. They replaced both the utility pole and the 50 kVA transformer about 4 years ago, which would have been a perfect opportunity to relocate it to the street. I don't know if you can download some images from my drive.
Would the 50 feed the lots 38L through R? If so the lines get to long and the voltage drop would be unacceptable.

Quote:
https://drive.google.com/file/d/0B4r7l039-pqHNDVtZTdYOUJkOTg/view?usp=sharing
I was able to view these photo's.

There many laws about safe clearance. No electric wire is supposed to be within 2 feet of anything else on a pole. Notice in the second photo that the neutral is below the xfmr., and from here it looks like their spacing is 7 feet between the primary and secondary on a xmfr. pole. All the utility's, power, phone cable, fiber, they have agreements about placement and height, and separation.

In photo 3 where you would prefer to have the xfmr. placed, notice the relation between the phase and the neutral, I think there it is 4 ft.? They just aren't going to place a xmfr. below the neutral for safety reasons. What you would like there, probably requires a taller pole, to maintain clearance's. Also raising the primary in both directions? All in all, it is a quality looking installation, but they are not nearly as pleasant to view as they once were.

I think your best angle is finding out if they really do have easement. Those trees will at some time make contact with the line. If the tree that makes contact with the line falls from outside the row, sometimes the power company will go after the landowner for not maintaining their trees.

Quote:
The split pole was a different one that was nearby. They didn't replace it until there was a fire and they had to send out a crew on a friday night to cut down branches and replace the pole. It screwed up an event
There is money to be made from chaos. Nation wide, there is an unbelievable amount of "delayed maintenance" that is past do. For L.A. W&P, there were crews near Compton that would go around tying ropes to the poles and the transformers because some fell to the street, do to everything rotting to the point of failure.
Everyone gets thrown from the plane to maintain altitude
June 25th, 2016 at 8:39:43 PM permalink
petroglyph
Member since: Aug 3, 2014
Threads: 12
Posts: 1940
Quote: Dalex64
Double the voltage, you will double the current. The resistor will get very hot.

If the Mexican utility is charging more for higher voltage, and billing by KWH, it is justified.
Look at a typical lamp. Inside it says maximum 60 watts, or there abouts. If you increase the current and therefore the heat, you have created a fire hazard in every ones home. Not justified.
Everyone gets thrown from the plane to maintain altitude
June 25th, 2016 at 10:27:57 PM permalink
Pacomartin
Member since: Oct 24, 2012
Threads: 706
Posts: 8142
Quote: petroglyph
Would the 50 feed the lots 38L through R? If so the lines get to long and the voltage drop would be unacceptable.
I was able to view these photo's.

No, those homes are about 17-18 years old and they have pad mounted 75 kVa transformers and underground service. I tried to draw little arrows to show which lots are served by each transformer in the development. The 50 kVA serves the lot to the north, the lot to the south which has a secondary garage apartment in the back. Each of these lines are about 100' to 120'. Also the 50 kVA has a 300' secondary line that crosses the street using 2 intermediate utility poles underneath the neutral and high voltage line to feed a house back across the street.

Quote: petroglyph
In photo 3 where you would prefer to have the xfmr. placed, notice the relation between the phase and the neutral, I think there it is 4 ft.? They just aren't going to place a xmfr. below the neutral for safety reasons. What you would like there, probably requires a taller pole, to maintain clearance's.


That pole is very old and has been shored up, so it must be replaced anyway. PP&Ls policy is to replace poles today that are in that condition. The lineman told me that it would require a new taller pole.

All the utility poles in the development are in the "right of way" of the street. That is land that is designated to the township for the street, but it is not paved. The paved section of the street is called a "cartway". This pole with the 50 kVA xformer is the only one on private property. The maps say "water easement", but I am fairly certain that a utility pole has been there since 1930.

In addition the two properties together have 108,000 square feet of land. A building lot only has to be 18,000 square feet. Without the easement, the two property owners could shave off 50' from each side and sell a 100' * 180' lot for pretty good money.
The utility poles are blue in the image. The magenta lines are the drops (not the 7200V lines)

https://drive.google.com/file/d/0B4r7l039-pqHX2tnampidTlsdDQ/view?usp=sharing
June 26th, 2016 at 6:35:59 AM permalink
Dalex64
Member since: Mar 8, 2014
Threads: 2
Posts: 1766
Quote: petroglyph
Look at a typical lamp. Inside it says maximum 60 watts, or there abouts. If you increase the current and therefore the heat, you have created a fire hazard in every ones home. Not justified.

You are talking about something different now.

I'm not talking about safety, just energy.
"Everyone is entitled to his own opinion, but not to his own facts." Daniel Patrick Moynihan
June 26th, 2016 at 11:59:42 AM permalink
Pacomartin
Member since: Oct 24, 2012
Threads: 706
Posts: 8142
Quote: Dalex64
If the Mexican utility is charging more for higher voltage, and billing by KWH, it is justified. The higher voltage will give higher amperage, disspipating/providing more Watts (work)



Quote: How much are you paying for electricity? J. Brad Grieve

After studying many homes here at Lake Chapala, it is interesting to learn to how much electricity each home uses and, more interesting, how much the home owner is paying for their electricity.Electricity is billed in kilowatt-hours (kWh),

...
One general issue could be the higher than average voltage at your home. In one case, I measured the voltage at a group of six homes and the voltage measured at each house was 140 volts; this means the home owners are actually consuming approximately 36% more kWh than a house that has exactly 120 volts all the time. By Federal Law ( Reglamento de la Ley del Servicio Público de Energía Eléctrica, Chapter Five, Article 18) the CFE must provide service within a 10% tolerance, which means residential voltages are to be regulated between 108 volts and 132 volts.

My experience here at Lake Chapala is that the voltages have been ranging between 126 and 132 volts however, for the few cases where the voltage has been consistently high over a period of time, the homeowner needs to report this voltage problem to the CFE.
http://www.mexconnect.com/articles/487-how-much-are-you-paying-for-electricity


While I agree that more voltage means more watts, it seems like the owner will be having more problems with light bulbs burning out, and with appliances or electronics failing. Appliances and electronics are much more expensive in Mexico than they are in the USA and replacing them more often can be costly.

Quote: petroglyph
Your electric service voltage is only guaranteed to be 120v +/- 10%. That blew me away when I learned that one. I almost posted to that when you mentioned Mexican utility's boosting voltage to increase service fees.


It would seem that the 10% tolerance applies to the USA as well. However, I think that as a matter of practice, it is much more common to exceed the tolerance in Mexico. I don't know if it is deliberate or not. That would be difficult to determine. But if the author is correct that 6 out of 6 homes in an area primarily occupied by Canadian and USA retirees measured 140V, then you have to wonder if it is by chance.