Why are there weights on power lines? The weights are mounted on flexible arms, typically a length of stiff cable, which allow the assembly to absorb energy that might otherwise be imparted to the longer power lines, or more accurately, that kinetic energy (movement) is removed from the lines, preventing oscillation.
Why do you put weights on a fishing line?
They are there to prevent the line from whipping up and down so much during high winds. Those oscillations can put more tugging force on the line than the line can handle. Putting weights on the line does slightly increase the tugging force on the line, but it prevents that force from becoming too large.
What happens to power lines in the winter?
In winter, ice and wind, even wind alone, can be just as dangerous and destructive to power lines, leading to a disruption in service. Each drop of freezing rain adds weight to power lines and their structures.
Does putting weights on a line increase tugging force?
Putting weights on the line does slightly increase the tugging force on the line, but it prevents that force from becoming too large. FYI, dampeners are those things which keep potted plants moist. And why would you assume the middle of the line remains stationary during oscillations?
What makes power lines stand out in a landscape?
Many places with power lines that feature markers have dense forests, mountain ranges or fields in the distance that can make the lines difficult to see. The bright colors of power line balls contrast well with dark green or grey landscapes to make power lines stand out.
How does buffeting work?
How does detuning affect conductor dynamics?
Which is more effective, stockbridge or stockbridge dampers?
Why do you put weights on a fishing line?
Why is it necessary to separate frequencies one from each other?
How is wind energy injected into the vertical motion?
Why is steel wire needed for pole to pole?
See 4 more
About this website
Why are there concrete weights on power lines?
Vibration dampers. Wind can cause aeolian vibration in taught cables. The weights prevent the vibration.
What are the metal triangles hanging from power lines?
What are those odd looking things you always see attached to power lines? Turns out, they're called lightning arresters and they're crucial to preventing certain blackouts.
What are the buckets on power lines?
The barrels that look like oil drums or trash cans hanging off utility poles are called transformers. They're used to lower the amount of voltage between the primary wires and secondary lines.
What are the silver things on power lines?
Mylar balloons are the metallic shiny, silver-like balloons which cause thousands of power outages each year when they float away and come into contact with power lines.
What does a red ball on a powerline mean?
visibility markersWell, those balls are visibility markers. They weigh about 17 pounds each, and you will often find them near mountain passes, in deep valley areas, near major freeway crossings and around airports. Visibility markers are placed on power lines to make the conductor crossings visible to aircraft pilots.
What happens if you touch a power line with a metal pole?
However, a ladder, a pole or even something as small as a wet string that comes in contact with a power line provides the electric current with a new path to the ground and can be dangerous.
Why don't birds get electrocuted when they sit on power lines?
Birds sitting on a wire don't touch the ground (or anything in contact with the ground), so electricity stays in the power line. But, if a bird touches a power line and equipment or other metal that is grounded, it gives electricity a path to the ground, and the bird could be shocked.
How many volts is lethal?
Assuming a steady current flow (as opposed to a shock from a capacitor or from static electricity), shocks above 2,700 volts are often fatal, with those above 11,000 volts being usually fatal, though exceptional cases have been noted.
What are the teardrop things on power lines?
It's called a “snowshoe” and is used to take up slack on communication lines to allow for splice repairs.
Why are there triangles on power lines?
The fins stabilise the lines in a windstorm to prevent them from whipping.
Why is there a piece of wood on the power lines?
In a wooded area, wires can rub against a tree trunk or branch, wearing down the bark. As the tree grows, it grows around the wire. That isn't necessarily a problem with some wires, but it is with higher-voltage electric lines.
Why do power lines have 3 wires?
Advantages. As compared to a single-phase AC power supply that uses two conductors (phase and neutral), a three-phase supply with no neutral and the same phase-to-ground voltage and current capacity per phase can transmit three times as much power using just 1.5 times as many wires (i.e., three instead of two).
Why are there triangles on power lines?
The fins stabilise the lines in a windstorm to prevent them from whipping.
What are the triangular flaps on power lines?
The fins are triangular pieces of electric equipment that are installed on power lines. They are a type of disconnect switch that our crews call “shark fins.” They are used to de-energize part of a power line when there is damage to the line.
What are the triangles on power poles?
If conductor separation couldn't be achieved and covering or reframing is impractical, perch guards (triangles—like the one pictured to left) have been used to deter birds from landing or nesting on a certain pole to begin with.
What are the tags hanging from power lines?
Bird flight diverters — or the “spinning things on power lines” as some folks call them — serve a dual purpose: They help keep the lights on and help preserve wildlife.
03C-003 WEIGHTS 9-2015 - Lindsey Manufacturing Co.
Copyright © 2015 Lindsey Manufacturing Co. P.O. Box 877, 760 N. Georgia Av., Azusa, CA 91702 USA Tel. +1(626) 969 3471 Fax. +1(626) 969 3177`
Socket Eye | PLP - Preformed Line Products
Body: forged steel (1), ductile iron (2), hot dip galvanized; Hardware: galvanized steel; Cotter Pin: stainless steel
Suspension & Support | PLP - Preformed Line Products
Preformed Line Products (PLP) serves the communications, energy, special industries and solar markets with connections you can count on.
Weights | Suspension Clamp | Clamps - Hubbell Power Systems
Hubbell Power Systems is a proud member of the Hubbell family. Click to learn more.
How does buffeting work?
Buffeting has an effect like galloping - long wavelength oscillation. Galloping, caused by interaction of vortexes with cable rotation, can be controlled by controlling the rotation of the cable-bundle. Buffeting can't be controlled that way, because the vortexes are shed off the hill, not off the cable.
How does detuning affect conductor dynamics?
Thus, while the despacering technique relies on changing the ice shape from a potentially unstable shape to a stable one, detuning accepts the ice shape but modifies the conductor dynamics in order to prevent the potential aerodynamic instability.
Which is more effective, stockbridge or stockbridge dampers?
These weights, in other words, are more effective for the low frequency vibrations linked particularly to torsional vibration expected at this specific location than stockbridge dampers would be. Stockbridge dampers are more useful for high frequency vibrations (flutter, 10Hz or so).
Why do you put weights on a fishing line?
Those oscillations can put more tugging force on the line than the line can handle. Putting weights on the line does slightly increase the tugging force on the line, but it prevents that force from becoming too large.
Why is it necessary to separate frequencies one from each other?
To avoid frequency coalescence between torsion and vertical movement, which is at the basis of the instability, it is necessary to separate the frequencies one from each other (so called detuning). So, the principle of detuning is the avoidance of such frequency coalescence due to torsional stiffness increase.
How is wind energy injected into the vertical motion?
Wind energy is injected to the vertical motion through torsional movement. The control of torsion can control the vertical movement. This occurs only when the torsional movement is close to the frequency of the vertical motion, which is valid for bundle conductor lines.
Why is steel wire needed for pole to pole?
The steel wire is suspended between the poles and is needed because the comms cable's own weight would inevitably cause it to stretch and fail.
What is the shape of ice on power lines?
As ice accumulates on power lines, it forms a teardrop shape. When wind blows, wires can start to move up and down in an oscillating motion. In essence, the wires encased in ice act like an aerodynamic airplane wing. This is known as “galloping.”.
How much ice can an OPPD line handle?
Distribution lines are designed to handle up to 1/2-inch of ice and 40-mph winds. New OPPD transmission lines are designed to handle 1 1/4 inches of ice with no wind, or winds of up to 90 miles-per-hour (equivalent to a weak EF1 tornado) with no ice.
What is it called when a wire touches the ground?
This is known as “galloping .”. Galloping can cause wires to eventually touch, resulting in a fault or subsequent power outage. The increased movement can also cause cross-arms to break, bringing lines to the ground.
What are the threats to electrical power lines?
Lightning, thunderstorms and tornadoes aren’t the only threats to the electrical infrastructure. In winter, ice and wind, even wind alone, can be just as dangerous and destructive to power lines, leading to a disruption in service. Each drop of freezing rain adds weight to power lines and their structures.
How does freezing rain affect power lines?
Each drop of freezing rain adds weight to power lines and their structures. It also adds more pressure and strain.
Who is Laura King-Homan?
Laura King-Homan is the managing editor of The Wire and a brand journalism strategist at Omaha Public Power District. She has nearly 20 years of print journalism and design experience, including the Omaha World-Herald.
Why are there line weights?
Modeling Operation Error: Error Code Number is 102007 Failed to perform blend. Failure while chamfering. 1
Why are there line weights?
I'm unclear on the printing. As I understand, we print/plot/publish using colors which is good but why then are there weights to layers? I am also considering the fact that on any files I have worked on in this office the line weights are always off/disabled.
How many pilot wires are there for street lights?
Three for the Active phases, Red Yellow Blue. One for Neutral and Two pilot wires for control of streetlights and hotwater systems
How many wires are there in a substation?
Near substations there may be even 8 wires where there are express streetlight and hotwater pilots.
Why are overhead wires insulated?
Note that overhead secondary (120/240v) wires are almost always insulated, mainly because they are mounted to the poles with much less spacing , or are even twisted together in many cases. Again, this insulation often degrades and hangs off the wires. See Youtube for some videos of these wires shorting. The arcs aren’t as impressive as at primary voltage but the much higher fault currents usually cause the rest of the insulation to burn, and the wires eventually melt and fall.
What happens if a bird squats on a wire?
When a bird squats down on a wire, its tendons cause the talons to close and clench automatically. That’s what allows them to sleep by sitting on top of a wire. They can’t unlock their grip until they straighten their legs. So if a bird perches on a wire and accidentally spreads its wings and touches two wires at once, it too will be electrocuted and die. But when that happens, if the shock doesn’t immediately blow the dead bird off the wire, the bird has lost its internal balance mechanism and it will flip over and the weight of the bird will straighten the legs, thereby releasing the automatic grip it had on the wire. It will fall to the ground and no one sees it. It won’t be long before a cat or something comes along and eats it.
How to tell if lightning shield wires are connected?
You can tell if this is the case by looking for insulators. The phase lines will be separated from the tower by long insulators, but the lightning shield wires will connect directly to it, grounding them out. This also protects the system against electrostatic build-up.
How many wires are there in 230/400?
For 230/400 Volts distribution in New Zealand there are often 6 wires.
What to do if a power line falls on your car?
The rubber tires are preventing you from contacting ground. If you absolutely must exit the car, before a rescue team can remove the wire and discharge the voltage that's now on the metal of the car (let's say, the car has caught fire, or something ), then it's imperative that you jump out of the car, without touching the metal and the ground, at the same time. And, don't think something thin, like a thin piece of cloth, or a thin gap of air, will be enough to separate you from the voltage or the ground. A high voltage spark can jump such a gap.
How does buffeting work?
Buffeting has an effect like galloping - long wavelength oscillation. Galloping, caused by interaction of vortexes with cable rotation, can be controlled by controlling the rotation of the cable-bundle. Buffeting can't be controlled that way, because the vortexes are shed off the hill, not off the cable.
How does detuning affect conductor dynamics?
Thus, while the despacering technique relies on changing the ice shape from a potentially unstable shape to a stable one, detuning accepts the ice shape but modifies the conductor dynamics in order to prevent the potential aerodynamic instability.
Which is more effective, stockbridge or stockbridge dampers?
These weights, in other words, are more effective for the low frequency vibrations linked particularly to torsional vibration expected at this specific location than stockbridge dampers would be. Stockbridge dampers are more useful for high frequency vibrations (flutter, 10Hz or so).
Why do you put weights on a fishing line?
Those oscillations can put more tugging force on the line than the line can handle. Putting weights on the line does slightly increase the tugging force on the line, but it prevents that force from becoming too large.
Why is it necessary to separate frequencies one from each other?
To avoid frequency coalescence between torsion and vertical movement, which is at the basis of the instability, it is necessary to separate the frequencies one from each other (so called detuning). So, the principle of detuning is the avoidance of such frequency coalescence due to torsional stiffness increase.
How is wind energy injected into the vertical motion?
Wind energy is injected to the vertical motion through torsional movement. The control of torsion can control the vertical movement. This occurs only when the torsional movement is close to the frequency of the vertical motion, which is valid for bundle conductor lines.
Why is steel wire needed for pole to pole?
The steel wire is suspended between the poles and is needed because the comms cable's own weight would inevitably cause it to stretch and fail.
