By DAVID CRAWFORD/ Montana State News

The west side of Bozeman was plunged into darkness twice over a recent weekend when a series of equipment failures plagued NorthWest Energy. Though inconvenient for those affected, no harm was reported due to the outages.

Jena Mathers, 26, a resident of the area thought it was like any other power outage. “I went to go reset my breaker. Then when the power didn’t come back on I started to worry, so I called NorthWestern Energy and the hold times were up to 30 minutes.  I just decided to sit by candlelight and chat with my roommate.”

Cole Schram, a supervisor at Costco, said, “We were worried about the customers; as soon as the lights went out, we got out flash lights and started escorting the customers to the registers.  Fortunately, 95 percent of the people were still able to make their purchases and there was no sense of real panic.”

On Jan. 25, two NorthWestern Energy transformer-banks tripped offline at the west side substation, causing power outages for over 3,800 customers in the Bozeman area.

According to Patrick Patterson, manager of operations for the Bozeman Division of NorthWestern Energy, “On Saturday morning at 6 a.m., the relay device gave a false trip, causing the new transformer to blow three of its five circuits, leaving the whole west side of town without power.” Patterson said the device was only 2 years old, and there was no evidence as to why it malfunctioned.

NorthWestern Energy transferred the load to an older transformer that hadn’t been in use.  Patterson says that they added the new transformer to the substation two years ago to manage the extra power that would be needed to sustain the residential and commercial growth on the west side of town.

All was well, until 6 p.m. Sunday night when the power went out again, this time causing outages to 8,200 residential and commercial customers, including Costco, Target and the Ridge. The outage reached from Valley Center Drive, to past Huffine Lane and from 19th Avenue all the way to Jackrabbit Lane.

This time the older transformer that the load was transferred to hit its cap rating and blew all five of its circuits leaving no way to provide service for the whole west side of Bozeman which was now in the dark.

Patterson said that their team was doing everything they could to get the power back on in a  reasonable amount of time, but having both transformers in the substation down, there was no way to direct power out of the substation—some troubleshooting needed to be done.

Within two hours, Northwestern Energy was able to re-route some of the load to feeders and other substations to restore the power.  The following Monday they were able to fix the relay on the new transformer and are now looking into setting up an alarm system to communicate when the load is reaching capacity.  As far as the faulty relay, they are looking into other service stations to see if they had issues with this device so changes can be made immediately.

Patterson said he was pleased with the way his team at Northwestern Energy handled the crisis and now they have protocols in place to prevent situations like this from happening in the future.  Patterson says this doesn’t happen very often and there is no need to worry about it happening again, “After all, 99 percent of the time we are always on.”

 – Edited by Jordan Garceau

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