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Some cases I've seen:
-Nature:
-lightning strikes near line
-fires (I've seen farmers burn weeds out from under a line - the fire ionizes the air, and with the added particulates in the air create a path to ground)
-snow storms/icing on lines (can cause lines to sag)
-high winds (can cause lines to blow out, possibly making contact with trees, or can cause enough stress to break poles). Winds can also blow stuff into the lines
-tornados
-Animals:
-Two bears climbing a pole
-Two owls fighting near a line
-Eagle/other large birds swooping down between conductors
-Eagle/other large bird pooping on conductors
-People:
-farmers touching power lines with harvesting equipment
-crop dusters attempting to fly under lines
-people crashing cars into poles
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Why do power transmission lines not have neutral conductor?
No neutral is necessary, because the transmission line's line currents are roughly balanced and, so, the phasor sum of those currents will be relatively insignificant, rendering the need for a neutral conductor to be an unnecessary expense. In practise, for most transmission towers, each of the three 'lines' comprises not just a single conductor but, rather, a number of conductors which are bundled together in order to reduce electric stress surrounding the line. The number of conductors per bundle increases with transmission voltages. In the UK, for example, 400-kV transmission lines normally comprise bundles of four conductors, whereas 275-kV transmission lines normally comprise bundles of two, and 132-kV lines just one. Running along the top of transmission towers is an earthed conductor, called a 'guard conductor', whose function is to protect the lines from lightning strikes during electrical storms. Many transmission towers also have two, separate, three-phase circuits -one circuit on each side of the tower. But, definitely, no neutral!
How many wire are used in transmission line?
Transmission lines are three-phase systems. There are three line conductors in a three-phase system. However, to reduce electric stress at higher voltages, these lines are frequently made up of 'bundled' conductors -so each line might have two, three, or four separate conductors. In addition, transmission towers usually carry separate circuits -i.e. separate three-phase circuits on opposite sides of each tower. So, in the UK for example, a typical 400-kV transmission line will consist of two, separate, three-phase circuits suspended on each side of each tower, with each line consisting of four bundled conductors. That's 24 conductors.
Why 400kVA and above the transmission line have bundled conductor?
To reduce the electric field intensity at the surface of the conductor which can lead to corona discharge and insulation breakdown. By using bundled conductors, the electric field is distributed between the four (in the case of 400-kV lines) conductors, thus reducing the field intensity per conductor.
Design a combinational circuit that accepts a three bit number and generates a binary output equal to twice the input value?
There is no need for a combinatorial circuit to multiply a number by two. A binary number, left shifted one place, is twice the original binary number. The specific answer to the question is that you would connect the three input lines to the three high order output line of four output lines, and connect the low order bit of the four output lines to logic 0. If the three input lines were labelled A, B, and C, the output would be A, B, C, and 0.
What is function of 89s52 microcontroller?
The 89S52 has four different ports. Each one of the ports has eight input/output lines. The ports are used to output data.
What causes 2004 Chevy half ton four wheel drive pickup Auto Transmission to slip in drive and not reverse?
a blown transmission
What is a stanza called that has four lines?
A stanza of four lines is called a quatrain.
Is three phase transmission line is example of bundle conductor?
'Bundled' conductors describe a line in which two or more conductors are supported from the same insulator chain. In the UK, 275-kV transmission lines typically use two conductors per line, and 400-kV transmission lines typically use four conductors per line. The purpose of bundling conductors is to spread the electric stress on the conductors (e.g. for four conductors, the same amount of electric flux will be 'shared' between the four conductors, rather than concentrated on the surface of one conductor).
What is a couplet quatrain?
A quatrain is, in poetry, a specific type of poem. There are not many rules to follow, and writing a quatrain is fairly simple. The quatrain contains just four lines. That's it and that's all the rules for writing a quatrain.
Can the engine coolant contaminate the transmission on a 1999 Toyota four runner?
Yes. The transmission fluid is cooled by a separate set of cooling lines in the radiator that cools your engine. If the radiator has an internal leak, cross-contamination may indeed occur. Only a little amount of engine coolant in your transmission can cause a transmission malfunction.
What are quadrilateral lines?
They are four lines that coincide pairwise in at least four distinct points.
Which figure has exactly four lines of symmetry?
A square has exactly four lines of symmetry.
What has four lines of symmetry?
If you think about it youwill know.But a Square has four lines of symmetry.
What is another word for stanza with four lines?
A quatrain is a stanza with four lines.
How many lines of a verse of sonnet?
Four. Qua is a prefix, meaning four.
How do you make the square with four lines answer with picture?
This site doesn't let you use pictures, but I assume you just connect all four lines, since a square has four lines...
How many lines does a stick figure have?
four lines
