Underground Cable Fault Finding

Finding the type of a fault in underground cables using a megger should not be a difficult task.

Underground cable fault finding.

We manufacture a wide range of fault location instruments that have been developed to be easy to use. When one or more cable conductors cores break it leads to discontinuity. 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. 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.

If the fault is on secondary cable knowing the exact route is even more critical. 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. But finding the exact location of the cable fault needs special techniques. In cable identification the faulty cables are identified from the fault free cables at the already determined site.

Open circuit fault as the name suggests this fault involves an open circuit in the conductors. Loop tests for locating faults in underground cables. 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. Cable fault on two cables.

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. Cable faults can be easily located if a sound cable runs along with the grounded cables. Finding the location of an underground cable fault doesn t have to be like finding a needle in a haystack. Fault locators are essential tools for personnel who install and repair underground electrical and communications cable.

These kinds of tests are carried out on short circuit faults or earth fault in underground cables. Route tracing is used to determine where the faulty cable lies and pinpointing is the process of determining the exact position of the cable fault. 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.

Cable fault finding guide. Following are the types of loop tests. There are many locating methods coupled with new detection technologies that make this task much easier and less time consuming. For further resources why not check out our video support library and our electrical testing electrical safety blog.

However you should understand that there is no single method or combination of methods that is best. Loop tests to finding cable faults.