How To Identify Faulty Underground Cable

It happens at one of my project....the underground cable from main substation experience a faulty.

This faulty cable causing the Main Switch Board to trip over certain period of energizing (not an instantaneous tripping).

Since the underground cable are laid over more than 150 meter, the location of the faulty cable may not be seen through naked eye.

In order to identify the fault location, voltage injection need to be apply to the faulty cable. This is to ensure the faulty cable will produce spark.

The spark that appear below ground will produce sound (sounds like dup...dup..dup). The sound was so soft that you need microscopic equipment to hear it.

By using that microscopic equipment, place the equipment on the ground and walk along the routing of the faulty cable until the sound are stronger. Once the fault location are found, the digging process started and cable rectification to be done.

This is how the video look like during the process.

Enjoy....