Equipment designed to dissipate electricity caused the power outage Tuesday that affected more than 6,000 customers in Durango and Hermosa.
The line arrester helps protect the system from lightning and surges of electricity. When a breaker at the Bodo substation sensed a problem, it shut off electricity to three substations, one in Greenmount, one near East Fourth Avenue and one near 32nd Street, which serves Hermosa, said Justin Talbot, manager of operations with La Plata Electric Association.
Crews checked lines between Bodo and the Greenmount substation and did not immediately find a problem. But when they tested the system, the arrester exploded.
“It physically blew glass all over,” he said.
If the arrester had exploded when the outage started, crews likely could have limited the almost two-hour outage to 45 minutes, Talbot said.
Talbot could not say why the arrester stopped working.
“At some point, it might have taken a shot of lightning, therefore shortening its lifespan,” he said.
This type of outage is rare, and this type of equipment is inspected monthly.
Once the arrester problem was discovered, the repair took about 45 minutes, Talbot said. If crews had started working on restoring power by rerouting it, customers would have likely faced the same wait.
In general, Talbot considers rerouting electricity when an outage lasts about two hours.
If more than 6,000 people had been affected by the outage, he would have shortened the timeline for rerouting power.