High voltage D-C testing of rubber-insulated wire

AT DIFFERENT STAGES in the manufacture of insulated wire and cable, various electrical and physical tests are made to ensure the quality and serviceability of the completed cable. One of the most important of these tests is the high voltage test, a-c or d-c. It may be applied to short sections of the insulated conductor as it passes through electrodes of various types, dry or wet, or to full factory lengths of the insulated wire, dry or wet.