How to Locate Cable Faults with the Murray Loop Test

There are 3 types of faults that are likely to occur in underground power cables. Open circuit faults occur due to broken conductors. Short circuit fault occurs due to insulation failure and earth fault occurs when the cable is torn. Since the underground cables are buried, if the fault occurs, it is invisible to our naked eye. By measuring the resistance, we can identify the faulted cable. Yes, we can find which cable has a fault. However, we cannot identify the exact location of the fault. There are several methods for locating the faults in underground cables. In this video, we are just concentrating on the Murray loop test. This is used to locate the earth fault and short circuit fault. It uses the principle of the Wheatstone Bridge. Chapters: 00:00 Intro 01:08 Wheatstone Bridge 02:13 Murray loop test for Earth fault 05:37 Murray loop test for short circuit fault 06:05 Limitation of Murray loop test