What DFA reported
In fair weather, with no customer complaints, DFA alerted that the same fault had occurred twice in 18 days on a 125-mile overhead circuit with about 20 unmonitored line reclosers. Its details (phase C, a single-phase operation, open intervals of 2.0 and 2.1 seconds, and the share of load each operation dropped) matched only one recloser.
What the crew found
That replaced the usual round of counter checks and cut the search area by 76%. DFA's fault current of 510 A, run through the circuit model beyond that recloser, pointed to a small area. The crew found a failing arrester within four spans.
Why it matters
Replacing it averted a future outage for 53 customers.
Keep reading
Two blinks a day apart led to a charred crossarm beside a pine forest
Nobody lost power for more than a blink. DFA matched the two faults, and the crew found a conductor burning into its crossarm six spans from the prediction.
Six faults in nine hours, no outage, no calls, and a branch removed
A hanging branch tripped a recloser six times without an outage. DFA grouped the faults into one report, and a targeted patrol found it.
Same fault twice in six days, and a dead squirrel found within hours
A breaker trip interrupted more than 1,200 customers twice. DFA linked the two faults within a minute, and the report took the crew to one pole.