This test is used to determine the insulation elasticity and propagation of damage through the wire/cable insulation. A wire/cable’s insulation should be sufficiently elastic so that if the wire is bent, there is little risk of the insulation cracking and jeopardizing the insulation integrity. A less elastic wire insulation is more likely that it will wear out and crack in-service.
This test is commonly included as an assessment following environmental exposure (e.g. thermal shock test, fluid immersion, etc.), but can also be performed as part of a new wire/cable assessment.
Visually examine the sample for defects or damage. Record any discrepancies.
Cut the sample to the specified length.
Affix one end of the sample to a mandrel of specified diameter. Affix to the other end the specified weight.
Slowly wrap the sample around the mandrel with minimum separation between successive wraps.
Wrap in the other direction.
Repeat to the required number of wraps.
Examine the sample insulation for any cracks and/or deformation.