DNV GL China

Fault locator

The unique fault locator feature of DNV GL's Smart Cable Guard detects and locates faults in any network to within 1% of the cable length

Helping you reduce SAIDI and SAIFI even further by detecting faults more easily and more accurately

Smart Cable Guard Fault Locator Helping you reduce SAIDI and SAIFI even further by detecting faults more easily and more accurately Network grounding configurations can make faults in underground cable networks difficult to detect. In particular, faults in high impedance grounded networks can stay undetected, or at least un-interrupted, for a long time. Furthermore a cross-country faults can leave the network with two faults to be found and repaired. Cable networks or networks with a mix of lines and cables are especially vulnerable.
Detect and Locate Faults Our Smart Cable Guard's unique Fault Locator feature detects and locates these faults as soon as they occur. This helps network operators reduce system outage duration (SAIDI) and outage frequency (SAIFI) even further. Unlike traditional protection equipment which measure 50 Hz short circuit currents, Smart Cable Guard's Fault Locator detects the travelling wave that comes from a fault. The wave indicates the start of a short-circuit current and is always present, independent of the network grounding. This means Smart Cable Guard can detect faults that would otherwise be missed.  When a travelling wave passes Smart Cable Guard's sensors, the arrival time of the first slope is recorded providing a very accurate indicator for the fault position. Within minutes of a breakdown occurring, the operator receives a message (via SMS or email) with its exact time and location.
Versatile monitoring  By detecting these waves Smart Cable Guard's Fault Locator can be used successfully in any situation, including:

  • In networks with low or high grounding impedance to find and locate any fault
  • Self-restoring faults which occur then recover, only to re-appear after a few days or months
    • normally difficult to locate because of their temporary nature
  • Faults with unwanted high-ohmic characteristics after it is switched-off
    • Smart Cable Guard is not influenced by the ohmic nature of the fault
All these faults are found immediately with a location accuracy of 1% of the cable length measured by Smart Cable Guard.