METHOD AND MEANS FOR TESTING INSULATION INTEGRITY ON LOW-VOLTAGE, UNSHIELDED ELECTRICAL CABLES

摘要

The insulation of low-voltage unshielded electrical cables (10) is tested for defects by placing the cable (10) in an atmosphere (14) of ionizable gas, applying a high-voltage transient electrical pulse from a power supply (18) to the electrical cable (10), and simultaneously applying a DC voltage from a DC power supply (20) to the electrical cable (10). The high-voltage transient electrical pulse creates an electrical field around the cable which is sufficient to cause corona discharge at a defect in the insulation of the cable. The DC voltage provides a DC current to the cable which travels along a corona discharge to ground, thereby indicating the presence of an insulation defect.