EnergyLines July 2017

What causes outages and how they are tracked


Have you ever wondered what causes a power outage? Glance up to the sky and the answer likely lies above. Nine times out of 10 when those clear blue skies change, electric service is threatened.


How can you outguess Mother Nature? You can’t. But that doesn’t sway the Hoosier Energy Power Delivery team. It challenges them.


They are always monitoring the weather, and if a storm rolls in or lightning strikes, they are ready.


“We prepare and stay up on the weather as best we can,” says Bob Hill, System Control Coordinator/EMS and Communications, a 17-year veteran of system operations. “If a line does go out of service, we are there as quickly as possible to determine the cause, isolate it safely and restore service.”


The team’s ground assault comes in different forms including technological controls that divert energy to nearby lines while crews work to fix the problem area.


Digital fault recorders (DFRs), a tool Hoosier Energy technicians were instrumental in developing more than three decades ago, are invaluable in identifying the problem area within a very short distance of a fault.


“We restore all the load we can by SCADA (electronic) control and notify member co-ops involved. The DFRs give us a pretty good idea where the fault is, but we won’t know exactly what is out or where to sectionalize the line until the switchmen get there,” says Stan Elmore, System Control Coordinator, Operations and Training.


Six classifications of power outages

6 classifications of power outages graphic
Hoosier Energy has identified six classifications of power outages. A common cause is the result of equipment exposed to the elements. When it is difficult to determine the source of an outage it is labeled as “unknown.” These outages are often due to tree limbs blowing onto lines during storms. Outages labeled “other” are operational outages where Hoosier Energy system control takes a line out of service for safety reasons such as a pole fire.













Equipment failure

Over time, the elements take their toll on the aging electrical infrastructure, contributing to 4 EnergyLines | July 2017 equipment failure. Nearly half the outages on the Hoosier Energy system are due to equipment failure or vegetation. High winds can upend trees, flinging them into a right-of-way in a matter of seconds while severe weather can cause the inner workings of the equipment to deteriorate.



Animals also cause outages. One recent Friday night, a raccoon snuck into the Sexton substation in the RushShelby Energy area, causing a 12-kilovolt regulator to fail, blowing a bank of fuses. As members slept, the co-op worked to seamlessly transfer energy flows and fix the problem, preventing a potential service disruption.



Accidents involving automobiles, farm equipment and the recent, but rare, helicopter mishap, can take out poles or lines, causing damage to the system and cause potentially large-scale outages.


No matter the cause, every outage is recorded in an interruption report, charted and diagnosed to prevent a similar reoccurrence.


In his 36 years at Hoosier Energy, Elmore has seen most everything. But the biggest deterrent to an outage, he says, are the proactive measures the crews take to prevent one from occurring. Workers in the field perform routine checks of gauges, relays, switches and lines.


Two new mobile substations now help crews keep energy flowing while working on the equipment. Recently, a mobile substation was placed in service while crews repaired an interrupter failure, preventing an outage in the New Albany area, Elmore said.


“If we notice something is not quite right, we investigate it and fix it.”


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