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suppose there is a Transmission line, and if there is some fault on the line, then how we can trace the fault. and suppose we do not have any Numerical relay on the panel, then how can we know the nature of the fault wheather it is overcurrent or any Earth fault.

Any body tell me the how this Transmissio line fualt can be trace out, whether that is over current or Earth fault and how can it be trace out on the actual line? how do we find the place where this fault occurs?