Localization of faults in low-voltage cables, with special reference to factory technique

Practical limitations of well-known fault-locating tests are considered, and some new tests capable of high accuracy are described. They include a d.c. valve-voltmeter circuit for core-to-sheath insulation faults, audio-frequency search methods for open-circuits, and radiofrequency tests for conductor defects. Mention is also made of fault localization based on wave-reflection effects. The paper deals mainly with factory technique for rubber- and plastic-insulated cables, but some of the methods can be applied to other types and to field work.