IEEE 563-2002 pdf download IEEE Guide on Conductor Self- Damping Measurements
3.Self-Damping Definition
The self-damping of a conductor subjected to a load T is defined by the power dissipated per unit length of aconductor vibrating in a natural mode, with a loop length ( and an antinode displacement amplitude y and arequency f The power per unit conductor length P is expressed as a function in the n ” mode 14:
P=f(T.lfy)
4. Conductor Definition
The conductor, to which the damping data are referred. should be clearly described. Together with the usualconductor data (stranding, weight per unit length, nominal RTS), information should be supplied on the typeof lubricant or grease applied to it or whether it is degreased, and on the origin of the tested specimen (thatis, if new ex-factory or taken from previously erected lengths). lf the specimen is taken from a previouslyerected length, the tensile loads to which it has been subjected and the period of time during which it hasbeen on the line should be stated.
5. Test Span Arrangement
The test span arrangement should be briefly described and shown in a sketch siilar to Fig 2. The free lengthL of the test specimen should be stated.
The free span length L,for damping measurements required for aeolian vibration problems, should prefera’bly be at least ten times longer than the longest loop length used in the tests. For consistent results, a spanlength greater than 50 m is recommended but satisfactory results can be obtained with spans in the range ot30 m. For shorter spans, the termination losses can be critical and it may be essential to use the standingwave method to measure the power loss in the conductor.
5.1 Termination
Preference should be given to a test arrangement which would minimize energy dissipation at the span endterminations. If there is uncertainty about this, the energy should be assessed and eventually accounted forby using the “standing wave” method.
To minimize the energy dissipation at the span terminations, the following precautions are suggested: 1) The terminating Þxtures be of massive concrete with a weight of the order of 10 percent of the ulti- mate tensile strength of the largest conductor to be tested. These should be a single piece and prefer- ably be common or solidly connected with the foundation to avoid relative motion occurring between the various components. 2) The termination losses may be minimized by terminating the conductor by a ßexure member, such as a ßexible cantilever, to avoid bending the conductor through a sharp radius of curvature where it would normally enter the clamp. (See Fig 4 .)
IEEE 563-2002 pdf download
PS:Thank you for your support!
