The Technical Department of SAPREM offers our customers an engineering service to give response to different requests.
1. TESTS IN LABORATORY SPAN
2. DAMPING STUDIES
3. AEOLIAN VIBRATION FIELD TEST RECORDING
All the tests, measurements and/or studies are in accordance with International Standards or, under request, in accordance with customer’s specifications
SAPREM has a test span of more than 40m long, to make different test such as,
- SELF-DAMPING TEST (ACSR, ACSR/AW, AAAC, AAC, OPGW, GTACSR, …)
- AEOLIAN VIBRATION TEST FOR CONVENTIONAL CABLES.
- AEOLIAN VIBRATION TEST FOR OPTIC FIBRE CABLES, with optical attenuation measurement.
- GALLOPING TEST, with optical attenuation measurement.
- DAMPER EFFECTIVENESS TEST IN LABORATORY TEST SPAN.
- SAG-TEMPERATURE TEST SPANS. SAPREM has two test spans, one indoor of more than 42m, and other outdoor of around 150m long, for sag-temperature measurement testing.
SAPREM has internationally recognised vibration simulation software to make Damping Studies of overhead line conductors (single or bundle), Ground wires or OPGW.
Our software is according with IEC 61897. SAPREM does not provide an installation table for the vibration dampers. Instead a personalised study of each case is conducted by means of a software that simulates the vibration conditions on the line and predicts the behaviour of the conductor, with or without armour rods, and up to six dampers in each end of the studied span.
As a result a report is given with a proposal for the necessary number of dampers and their location for each span in such a way that, the limit strain in the conductor strands at the exit of the tension or suspension clamp, as well as that of the damper, are never going to be reached, making sure that the amplitude of the damper does not surpass its fatigue limit.
Study WITHOUT dampers
Study WITH dampers
To carry out a damping study of this kind, there are some parameters that SAPREM requires to the customer:
a) Line identification: country, name, voltage, etc.
b) Mechanical and dimensional characteristics of conductor.
c) Description of clamps and armour rods, if any.
d) Tensile load in the average span, without overload, at the average temperature in the coldest month of the year. When this tensile is not available, it must be provided enough data for its calculation, specially the above mentioned temperature or a logic approximation to it.
e) Minimum, average and maximum span length.
f) Orography, type of terrain and vegetation along the line. Eolical particularities.
g) Special spans: crossings of lakes, rivers, gully and steep riverbanks, spans over 700 m. Description of other particular characteristics.
Please, contact the Technical Department of SAPREM to ask for Damping Studies Questionnaire.
SAPREM has available several vibration recorders to monitoring overhead lines.