I was just surfing on the net when I read your question. I donnot know too much how much we can tell about the manufacturers.
For distribution lines fault locator you can find the right products manufactured by Hathaway (now belonging to QUALITROL). There are two existing products, the TWS and...
For overhead lines one technic is to use travel wave fault locator. It can be used on tranmission lines of any voltage. The signal is taken from the CT. Each fault occuring on the line will generate a pulse that will travel in both directions. Providing that a locator is installed at both ends...
