Underground Cable Fault Finding

Cable fault on two cables.

Underground cable fault finding.

Loop tests for locating faults in underground cables. For further resources why not check out our video support library and our electrical testing electrical safety blog. We ve assembled helpful technical guides on cable testing and cable fault location from leading manufacturers in the field if you are looking for something specific don t hesitate to contact us. Two of the popular techniques are the murray and varley loop tests for locating faults in underground cables this article explains about few other popular techniques for locating faults in underground cables viz.

This discontinuity also occurs when the cable comes out of its joint due to mechanical stress. Following are the types of loop tests. Loop tests to finding cable faults. Cable faults can be easily located if a sound cable runs along with the grounded cables.

If the fault is on secondary cable knowing the exact route is even more critical. Fault locators are essential tools for personnel who install and repair underground electrical and communications cable. We manufacture a wide range of fault location instruments that have been developed to be easy to use. Open circuit fault as the name suggests this fault involves an open circuit in the conductors.

Before attempting to locate underground cable faults on direct buried primary cable it is necessary to know where the cable is located and what route it takes. Finding the type of a fault in underground cables using a megger should not be a difficult task. But finding the exact location of the cable fault needs special techniques. There are many locating methods coupled with new detection technologies that make this task much easier and less time consuming.

A common approach to test cable and determine insulation integrity is to use a hi pot test in a hi pot test a dc voltage is applied for 5 to 15 min. Correctly used ground fault locator and cable fault locator equipment can accurately identify the location and depth of underground cable even when it is inside conduit and can pinpoint breaks or faults in underground cable. In cable identification the faulty cables are identified from the fault free cables at the already determined site. Cable fault finding guide.

Finding the location of an underground cable fault doesn t have to be like finding a needle in a haystack. This is known as open circuit fault. Ieee 400 specifies that the hi pot voltage for a 15 kv class cable is 56 kv for an acceptance test and 46 kv for a maintenance test ansi ieee std. When one or more cable conductors cores break it leads to discontinuity.

These kinds of tests are carried out on short circuit faults or earth fault in underground cables. The cable fault location process has multiple steps and it s vital that it s completed as quickly and safely as possible to minimise the time that customers are without supply.