IEEE 400.2-2004

This guide describes very low frequency (VLF) withstand and diagnostic tests and the measurements that are performed in the field on service-aged shielded medium voltage cables with extruded and laminated dielectric insulation. VLF test methods utilize ac signals at frequencies less than 1 Hz. The most commonly used, commercially available, VLF test frequency is 0.1 Hz. Whenever possible, cable systems are treated in a similar manner to individual cables. Charts are included as an aid in identifying the effectiveness of the VLF test for various cable insulation problems.