Low temperature mechanical tests
By performing elongation, bending and/or impact tests at low temperatures, the mechanical performance of cables during operating in extreme cold is verified.
Elongation at low temperature: UNE-EN 60811-505
This test is for round cables with a diameter over 12.5 mm and flat cables with a width over 12.5 mm, when preparing dumbbell samples is possible.
By using a tensile machine fitted with a cooling device or inside a refrigeration chamber, the dumbbell samples are taken down to the temperature established in the specific standard for the product
When the sample is stable at the required temperature, a tensile force is applied and the maximum elongation is assessed. The test is considered to be satisfactory if the elongation achieved is higher than the requirements established in the standard for the specific product
Impact test at low temperature: UNE-EN 60811-506
To perform this test, the impact equipment and the sample must be prepared in the same refrigeration chamber to the temperature set in the standard for the specific product (Link to cable types).
After dropping the hammer on the sample it is tempered again at room temperature and then inspected visually to check for any visible cracks after the impact.
Bending tests at low temperature: UNE-EN 60811-504
This test is for round cables with a diameter less than or equal to 12.5 mm and flat cables with a width less than or equal to 12.5 mm. It is also applicable to cables of larger dimensions if required in the specific product standard.
- Test applied to insulation
The samples are prepared by removing the outer coating of the insulated conductors.
Once the sample is fitted to the equipment, based on a rotating mandrel, it is placed in the refrigeration chamber to the temperature set in the standard for the specific product
After the cooling period, the sample is made to turn on the mandrel for sufficient time to reach room temperature before inspecting it for visible cracks without the sample previously being unwound.
- Test applied to sheaths
To assess the bending performance at low temperature of the sheath, the complete cable must be tested, separating the sheath from any coatings.
The prepared sample is fitted to the equipment, based on a rotating mandrel, it is placed in the refrigeration chamber to the temperature set in the standard for the specific product After the cooling period, the sample is made to turn around the mandrel and tempered to room temperature. It is then inspected visually for any cracks without unwinding the sample from the mandrel.