* Conduct pressure testing on the pigtail by slowly pressurizing the pigtail and checking for damage. If the threads are damaged, the connection should be replacedThe cables may fail due to any combination of electrical, mechanical or thermal factors. TYPES OF COMMON DEFECTS IN LV CABLE 3. The corkscrew or “pigtail” effect occurs when torsional forces are released during operation due to incorrect cable configuration, pitch length and pitch direction. Cables that are constructed in layers rather. When the connection works for a few minutes, then drops unexpectedly, the fiber pigtail may have internal fractures that move under slight cable pressure.