Spiral Vibration Dampers: The Ultimate Review Wind-induced vibration also called Aeolian vibration o
Wind-induced vibration also called Aeolian vibration of overhead cables is a common occurrence throughout the world.
Aeolian vibration is a major issue in transmission lines because it results in fatigue failure of conductor strands or equipment associated with support such as cable suspension clamps, deadends, spacers, spacer dampers, etc.
The figure below shows the effect of Aeolian vibration on a stranded wire.
A spiral vibration damper is used to lengthen the cable line’s lifespan. It reduces wind-induced vibration or Aeolian vibration in cables such as the optical ground wires (OPGW), overhead shield wires (OHSW), and delicate cables and conductors up to 0.75 inches (diameter).
When strands break their share of electric current is shared with other strands causing conductor fatigue. Using SVDs is the easiest and cheapest way to prevent this kind of breakage from happening.
As the length and tension of a cable line increases, its self-damping properties decrease. Generally, the self-damping abilities of a strand are related to the looseness of the individual strands or how they can freely move. Therefore, vibration activity is more prevalent in the coldest months when the cable is tighter.
This issue is resolved by introducing additional damping using damping devices such as Spiral vibration dampers (SVDs). The SVDs reduce the stress in the conductor strands.
The intensity needed to bring about Aeolian vibration also varies. It depends on factors like the topography of the area, height and direction of the cable, span length, and types of conductors and clamps. For example, the smaller the diameter of the cable or conductor, the higher the frequency of the vibration. The SVDs should therefore meet the requirements for wind velocity range or frequency range.
The spiral vibration dampers need to be placed in a suitable position to ensure success. They should be installed near but not in contact with the following support equipment (leave a gap about 6-8 inches).
SVD installation is easy and, more or less, follows the same procedure for all manufacturers.
Step 1: Install ADSS (All Dielectric Self Support) cables correctly between poles or any securing points along the lines. This should be done according to the manufacturer’s instructions.
Step 2: Hold the SVD next to the ADSS cable with the gripping end away from you and the damping area closer to you. This is done to determine the proper gap to leave before you start installing.
Note: As mentioned earlier, the SVD should never touch the armor rods or any hardware at the end. There should be an approximate 8-inch gap from the ends of the hardware to the SVD.
Step 3: Install the SVD by wrapping it around the line starting from the gripping end or tighter end fast. This is done until the whole SVD length wraps around the cable.
The spiral vibration damper is very vital in reducing the Aeolian vibration and increasing the lifespan of transmission lines. Remember, these problem-causing vibrations are caused by smooth winds that occur day to day (2-15 mph). This means that the SVD should be a permanent requirement for your cable line.
At Powertelcom, we produce the best spiral vibration dampers using the latest tech and automatic machinery. Our SVDs are made of weather-proof, non-corrosive material with a conduction-friendly spiral/helical design.
We have a wide array of SVDs suitable for different cable sizes and vibration frequencies. Each cable is color coded to make it easy for our customers to get the right one for their application.
Contact us today and get the best guidance on SVDs, SVD installation, and other electrical devices.