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WAYS AND MEASURES IN PROTECTING DISTRIBUTION LINE CONDUCTORS FROM DAMAGES

WAYS AND MEASURES IN PROTECTING DISTRIBUTION LINE CONDUCTORS FROM DAMAGES
 What are the ways in protecting line from damages that occur in transmission and distribution lines?



Gentle Handling of Cable - Careful handling in the field to avoid scratches, cuts or kinks in the conductor is desirable during the field operations of paying out, stringing, and tying or clipping in.

Follow Sag-Tension Charts - Sagging conductors at tensions higher than recommended increases susceptibility to aeolian vibration. Sagging in at tensions lower than recommended reduces the probability of aeolian vibration but increases susceptibility to galloping.

The Use of Armor Rods on Conductors - Armor Rods are intended for clamp supports, but they can also be used at tied supports. Armor rods are effective in sacrificing their surface to abrasion instead of the conductor’s outside surface. In addition, they provide protection against electrical burning of the conductor from flashovers. Armor rods distribute the bending stresses imposed on the conductor at line angles.

The Use of Ties - PLP factory-formed ties with pads are recommended as a superior replacement for a hand tie wire, with or without profective rods. One reason is that the tie surrounds the conductor with a resilient cushion that eliminates abrasion at the conductor insulator interface. By comparison, protective rods sacrifice their outside surfaces to abrasion but do not eliminate abrasion. Ties not only replace protective rods, but also replace hand tie wire or clamp top insulators as a means of securing conductors to insulators.

Use of Dampers - For distribution lines where experience indicates that prolonged periods of aeolian vibration may lead to fatigue of the conductor, cause inner wire fretting, or score the insulator’s glaze, it is recommended that dampers be installed. Because all of the conditions conductive to aeolian vibration cannot be continuously monitored in the field, emphasis is on a utility’s own experience in recognizing damage caused by aeolian vibration.
A number of precautionary measures to counteract conductor motion and its effects are currently available to the line designer and construction personnel. These methods vary in expense, complexity and effectiveness. A brief description and qualitative estimate of the feasibility of each protective measure are contained in the following paragraphs.

Comments

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