This calculator is designed for engineers and professionals working in electrical power systems to determine the sag and tension of overhead lines, ensuring safe and efficient power distribution.
Calculate Sag and Tension
Results
Data Source and Methodology
Calculations are based on standard engineering practices. Refer to ASCE 7-22 for detailed methodologies. All calculations strictly adhere to the formulas and data provided by this source.
The Formula Explained
The sag \( S \) of a conductor is calculated using the formula:
Glossary of Variables
- Span Length (L): The horizontal distance between two support points.
- Conductor Weight (w): The weight of the conductor per meter length.
- Tension (T): The force applied to the conductor to keep it taut.
- Sag: The vertical distance between the highest and lowest point of the conductor.
How It Works: A Step-by-Step Example
For a span length of 150m, conductor weight of 1.2kg/m, and tension of 1500N, the sag is calculated as follows:
Using the formula,
\[ S = \frac{1.2 \times 150^2}{8 \times 1500} \]
The resulting sag is approximately 1.35 meters.
Frequently Asked Questions (FAQ)
What is sag in an overhead line?
Sag is the vertical distance between the highest point of a conductor and the lowest point. It is crucial for determining the safe clearance of power lines.
How is tension related to sag?
Tension is inversely related to sag; increasing the tension in a line reduces the sag, which can help maintain safe clearances.
Why is calculating sag important?
Accurate sag calculations ensure the safety and reliability of power transmission, preventing contact with obstacles and maintaining proper clearance.
What factors affect sag in overhead lines?
Sag is affected by span length, conductor weight, tension, temperature, and wind load.
Can weather conditions influence sag?
Yes, weather conditions such as temperature changes and wind can significantly influence sag and tension in overhead lines.
Formula (LaTeX) + variables + units
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S = \frac{w \cdot L^2}{8 \cdot T}
S = \frac{1.2 \times 150^2}{8 \times 1500}
\[ S = \frac{w \cdot L^2}{8 \cdot T} \]
- No variables provided in audit spec.
- NIST — Weights and measures — nist.gov · Accessed 2026-01-19
https://www.nist.gov/pml/weights-and-measures - FTC — Consumer advice — consumer.ftc.gov · Accessed 2026-01-19
https://consumer.ftc.gov/
Last code update: 2026-01-19
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