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_______________ Insulator is used when there is a Long Span or dead-end or sharp corner in transmission line
Suspension
Strain
Pin
Shackle
Strain
A strain insulator is designed to handle high mechanical tensile loads and is used in transmission lines where the conductor ends, changes direction (sharp corners), or spans a long distance. Unlike suspension insulators which carry the weight of the conductor vertically, strain insulators are installed in a horizontal plane to counteract the mechanical tension of the line.
A strain insulator is designed to handle high mechanical tensile loads and is used in transmission lines where the conductor ends, changes direction (sharp corners), or spans a long distance. Unlike suspension insulators which carry the weight of the conductor vertically, strain insulators are installed in a horizontal plane to counteract the mechanical tension of the line.
TtotalтАЛ=TconductorтАЛ тАФ the tensile force balanced by the strain insulator string
VstringтАЛ=VphaseтАЛ├ЧNunitsтАЛ тАФ approximate voltage handling capacity proportional to unit count
In a long span or dead-end, the tension on the conductor is extremely high. To relieve the transmission towers from this excessive mechanical stress, strain insulators are used. They are typically arranged horizontally so that the mechanical tension is transmitted through the insulator strings to the support tower, while maintaining electrical isolation between the live conductor and the tower structure.
Strain insulators are used at dead-ends, sharp corners, and long river spans.
They are placed in a horizontal orientation to resist mechanical tension.
For low voltage lines, shackle insulators are used as strain insulators.
For high voltage lines, a string of suspension insulators is used in a horizontal configuration as a strain insulator.
High mechanical strength to withstand heavy conductor tension
Provides reliable isolation at termination points
Requires more physical space compared to vertical suspension arrangements
Installation is more complex due to the requirement for heavy-duty dead-end towers
Transmission line dead-end towers
Large river or valley crossings
Sharp bends in distribution and transmission routes
Pin insulators are only for voltages up to 33kV and cannot handle high mechanical tension.
Suspension insulators are typically used vertically to support the weight of the conductor.
Shackle insulators are a type of strain insulator used only for low voltage distribution lines.
B is correct тАФ Strain insulators are specifically designed to withstand the high mechanical tension encountered at dead-ends and sharp turns in transmission lines.
Always remember: 'Pin' is for support, 'Suspension' is for vertical weight, and 'Strain' is for horizontal tension.