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Why are electricity wires connected to poles with a sag between it?
Two reasons: 1. It almost impossible to pull a wire tight enough that it is straight. 2. The sag also can "give" a little if the wires shrink to to cold. If they could not "give" a little, then they would simply break.
Why overhead electric cables sag on hot sunny days?
There's little choice. Conductors (not 'cables') sag, because of their weight. However, there's also a practical reason for deliberately allowing conductors to sag; if they were too 'tight', then they would not be able to contract during cold weather without pulling the poles over.
What will happen to the telephone lines if they are fitted tightly from pole to pole?
When a pole shifts with the earth it will pull the wires apart and cause a break somewhere in the line. The poles are meant to suspend the wires in air, not to stretch them... Accurate answer is the lines will break. While breaking is not normally due to poles shifting, that could happen. The reason the wires are slung loosely is because of the expansion and contraction properties of the metal wires. If you look at the lines in the winter, they do not sag much (are tighter) and in the summer the sag is pronounced (looser). If they were strung tightly, they would eventually break during the cold weather.
What happenes to telephone wires when they expand with heat?
became sag loosen
How many droop have in 1 ml?
To droop is to hang loosely or sag. There is no volume associated with it.
Why is a sag provided in the transmission line?
Sag is provided in transmission lines in order to lessen the tension of the transmission lines. Sag literally means to be bend in shape. In overhead transmission lines , the difference in level between points of supports (towers or utility poles) and the lowest point on the conductor is called a sag. Explanation: While erecting an overhead line, it is very important that the conductors are under safe tension. If the conductors are too much stressed between the supports ( towers, utility poles), then the stress on the conductors may reach to an unsafe level and the conductor may break due to excessive pressure ( i,e tension). in order to permit safe tension in the conductors, the conductors ( i.e the transmission lines) are not fully stretched but are allowed to have a dip or a sag.
Why electric transmission lines between two poles are found to sag in summer?
The metal conductor in the line contracts in the cold of winter making the line more taunt, and expands making the line longer in the summer's heat. Thus the summer 'sag.'
Why are electric wires left lose between poles?
To allow for expansion and contraction of the metal wire. In the heat of the summer, the wire will expand (lengthen) and will appear to sag between the poles. In the cold of winter, the wire contracts (shortens) and will tighten up between the poles.
What is the definition of Sag current in transmission line?
sag means the deepest point of the conductorAnswerSag is defined as follows: 'Sag, under any system of conductor loading, is the distance measured in the direction of the resultant load, between the conductor and the midpoint of a straight line joining adjacent supports'.So, draw an imaginary line beween two adjacent supports (towers or poles) and, from the midway point, draw a vertical line to where it intersects the conductor, and that vertical line represents the sag.
What is sag in transmission lines?
Catenary
How do sag's in power transmission formed?
The plural of sag is sags, not sag's! Sag is caused by the weight of the conductor between its supports, and is (a) unavoidable and (b) necessary to allow for the conductor's expansion and contraction during variations in temperature. When surveyors design a power line, the amount of necessary sag is calculated and built into the design, while ensuring that the clearance between the conductor and the ground remains within safe limits.
The different between sag and surges?
The different between sag and surges
Why do power lines sag lower between telephone poles in summer than winter?
the metal inside the wire heats up leading to the expansion of the wire.
Why do telephone lines sag instead of being straight across?
Everything has a weight/mass. The larger the distance between the poles, the more wire is used, which means more weight. Gravity pulls down on the wire causeing it to sag where not supported. If construstion workers were to make the wire as tight as possible it may pull the poles right out of the ground. This also provides flexibility in times of high winds or when the poles shift. In addition, a sag is intentionally provided to provide slack for when the line contracts in cold weather.
Why sag setting in Transmission line?
The sag setting is necessary because it is physically impossible to have a suspended line with no sag. The sag is specified because there has to be a minimum clearance value for the height above ground at the centre of the sag where the cable is at its minimum height.
What is hot curve and cold curve in the sag template of Transmission line design?
plot of conductor sag and span lengths
Is production of sag is useful for transmission of line?
It's unavoidable.
