What is sag of conductor?
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What is sag of conductor?
In a transmission line, sag is defined as the vertical difference in level between points of support (most commonly transmission towers) and the lowest point of the conductor. The shape of the conductor is a parabola and the lowest point of the conductor is O.
How is sag conductor calculated?
Calculation of Sag:
- Case1: When the conductor supports are at equal level.
- Sag = WL2/8T.
- Case2: When the conductor supports are at unequal level.
- Sag = WtL2/2T.
Can a conductor have uniform volume charge density?
Volume density is zero inside a conductor.
What is the reason for the sag in the transmission line?
The lines are often heavily loaded because of increased power consumption, and the conductors, which are generally made of copper or aluminum, expand when heated. That expansion increases the slack between transmission line structures, causing them to sag.
Why the conductor sag should be minimum?
The conductor sag should be kept to a minimum in order to reduce the conductor material required and to avoid extra pole height for sufficient clearance above ground level.
Why is SAG important power sector sag?
The difference in level between the points of support and the lowest point on the conductor is called as sag. Keeping the desired sag in overhead power lines is an important consideration. If the amount of sag is very low, the conductor is exposed to a higher mechanical tension which may break the conductor.
What factors affects sag?
Factors affecting the sag
- Conductor weight – Sag of the conductor is directly proportional to its weight.
- Span – Sag is directly proportional to the square of the span length.
- Tension -The sag is inversely proportional to the tension in the conductor.
- Wind – It increases sag in the inclined direction.
What is SAG and formula?
So, when the conductor has wind and ice loading. i) the sag of the conductor will be:- This sag represents the slant sag in a direction making an angle θ to the vertical. We can easily calculate the value of slant slag by using the above formula. ii) The vertical sag = S cos ϴ
Why is charge density inside a conductor 0?
It has a direction determined entirely by the charge on its surface. It is always zero. The net electric field inside a conductor is always zero. This surface can be imagined around any point inside the conductor with the same result, so the charge density must be zero everywhere inside the conductor.
Why electric field inside a conductor is zero?
Electric field is zero inside a charged conductor. For a charged conductor, the charges will lie on the surface of the conductor.So, there will not be any charges inside the conductor. When there is no charge there will not be electric field.
What are the effects of sag?
If there is too much sag in a transmission line, it will increase the amount of conductor used, increasing the cost more than is necessary. It Causes Power Failure: When a transmission line sag excessively, it is liable of causing power failure.
What are the factors affecting sag?
Factors affecting the sag Conductor weight – Sag of the conductor is directly proportional to its weight. The weight of the conductors is increased due to ice loading. Span – Sag is directly proportional to the square of the span length. Longer span gives more sag.